[dpdk-dev] validate_abi: build faster by augmenting make with job count

  From: Neil Horman <nhorman@redhat.com>

John Mcnamara and I were discussing enhacing the validate_abi script to build
the dpdk tree faster with multiple jobs.  Theres no reason not to do it, so this
implements that requirement.  It uses a MAKE_JOBS variable that can be set by
the user to limit the job count.  By default the job count is set to the number
of online cpus.

Signed-off-by: Neil Horman <nhorman@tuxdrier.com>
CC: Thomas Monjalon <thomas.monjalon@6wind.com>
CC: "Mcnamara, John" <john.mcnamara@intel.com>
---
 scripts/validate-abi.sh | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)
  

2016-07-20 13:09, Neil Horman:
> From: Neil Horman <nhorman@redhat.com>
> 
> John Mcnamara and I were discussing enhacing the validate_abi script to build
> the dpdk tree faster with multiple jobs.  Theres no reason not to do it, so this
> implements that requirement.  It uses a MAKE_JOBS variable that can be set by
> the user to limit the job count.  By default the job count is set to the number
> of online cpus.

Please could you use the variable name DPDK_MAKE_JOBS?
This name is already used in scripts/test-build.sh.

> +if [ -z "$MAKE_JOBS" ]
> +then
> +	# This counts the number of cpus on the system
> +	MAKE_JOBS=`lscpu -p=cpu | grep -v "#" | wc -l`
> +fi

Is lscpu common enough?

Another acceptable default would be just "-j" without any number.
It would make the number of jobs unlimited.
  

On Wed, Jul 20, 2016 at 07:40:49PM +0200, Thomas Monjalon wrote:
> 2016-07-20 13:09, Neil Horman:
> > From: Neil Horman <nhorman@redhat.com>
> > 
> > John Mcnamara and I were discussing enhacing the validate_abi script to build
> > the dpdk tree faster with multiple jobs.  Theres no reason not to do it, so this
> > implements that requirement.  It uses a MAKE_JOBS variable that can be set by
> > the user to limit the job count.  By default the job count is set to the number
> > of online cpus.
> 
> Please could you use the variable name DPDK_MAKE_JOBS?
> This name is already used in scripts/test-build.sh.
> 
Sure

> > +if [ -z "$MAKE_JOBS" ]
> > +then
> > +	# This counts the number of cpus on the system
> > +	MAKE_JOBS=`lscpu -p=cpu | grep -v "#" | wc -l`
> > +fi
> 
> Is lscpu common enough?
> 
I'm not sure how to answer that.  lscpu is part of the util-linux package, which
is part of any base install.  Theres a variant for BSD, but I'm not sure how
common it is there.
Neil

> Another acceptable default would be just "-j" without any number.
> It would make the number of jobs unlimited.
  

> On Jul 20, 2016, at 12:48 PM, Neil Horman <nhorman@redhat.com> wrote:
> 
> On Wed, Jul 20, 2016 at 07:40:49PM +0200, Thomas Monjalon wrote:
>> 2016-07-20 13:09, Neil Horman:
>>> From: Neil Horman <nhorman@redhat.com>
>>> 
>>> John Mcnamara and I were discussing enhacing the validate_abi script to build
>>> the dpdk tree faster with multiple jobs.  Theres no reason not to do it, so this
>>> implements that requirement.  It uses a MAKE_JOBS variable that can be set by
>>> the user to limit the job count.  By default the job count is set to the number
>>> of online cpus.
>> 
>> Please could you use the variable name DPDK_MAKE_JOBS?
>> This name is already used in scripts/test-build.sh.
>> 
> Sure
> 
>>> +if [ -z "$MAKE_JOBS" ]
>>> +then
>>> +	# This counts the number of cpus on the system
>>> +	MAKE_JOBS=`lscpu -p=cpu | grep -v "#" | wc -l`
>>> +fi
>> 
>> Is lscpu common enough?
>> 
> I'm not sure how to answer that.  lscpu is part of the util-linux package, which
> is part of any base install.  Theres a variant for BSD, but I'm not sure how
> common it is there.
> Neil
> 
>> Another acceptable default would be just "-j" without any number.
>> It would make the number of jobs unlimited.

I think the best is just use -j as it tries to use the correct number of jobs based on the number of cores, right?
  

2016-07-20 19:47, Wiles, Keith:
> On Jul 20, 2016, at 12:48 PM, Neil Horman <nhorman@redhat.com> wrote:
> > On Wed, Jul 20, 2016 at 07:40:49PM +0200, Thomas Monjalon wrote:
> >> 2016-07-20 13:09, Neil Horman:
> >>> From: Neil Horman <nhorman@redhat.com>
> >>> +if [ -z "$MAKE_JOBS" ]
> >>> +then
> >>> +	# This counts the number of cpus on the system
> >>> +	MAKE_JOBS=`lscpu -p=cpu | grep -v "#" | wc -l`
> >>> +fi
> >> 
> >> Is lscpu common enough?
> >> 
> > I'm not sure how to answer that.  lscpu is part of the util-linux package, which
> > is part of any base install.  Theres a variant for BSD, but I'm not sure how
> > common it is there.
> > Neil
> > 
> >> Another acceptable default would be just "-j" without any number.
> >> It would make the number of jobs unlimited.
> 
> I think the best is just use -j as it tries to use the correct number of jobs based on the number of cores, right?

No Keith, -j alone use as much jobs as it can create, i.e. much more than
the number of CPUs.
I have no measure but I remember it is less efficient than giving a number
based on available CPUs (with a multiply factor to avoid idling between jobs).
For a default value, both approaches are fine.
  

On Wed, Jul 20, 2016 at 07:47:32PM +0000, Wiles, Keith wrote:
> 
> > On Jul 20, 2016, at 12:48 PM, Neil Horman <nhorman@redhat.com> wrote:
> > 
> > On Wed, Jul 20, 2016 at 07:40:49PM +0200, Thomas Monjalon wrote:
> >> 2016-07-20 13:09, Neil Horman:
> >>> From: Neil Horman <nhorman@redhat.com>
> >>> 
> >>> John Mcnamara and I were discussing enhacing the validate_abi script to build
> >>> the dpdk tree faster with multiple jobs.  Theres no reason not to do it, so this
> >>> implements that requirement.  It uses a MAKE_JOBS variable that can be set by
> >>> the user to limit the job count.  By default the job count is set to the number
> >>> of online cpus.
> >> 
> >> Please could you use the variable name DPDK_MAKE_JOBS?
> >> This name is already used in scripts/test-build.sh.
> >> 
> > Sure
> > 
> >>> +if [ -z "$MAKE_JOBS" ]
> >>> +then
> >>> +	# This counts the number of cpus on the system
> >>> +	MAKE_JOBS=`lscpu -p=cpu | grep -v "#" | wc -l`
> >>> +fi
> >> 
> >> Is lscpu common enough?
> >> 
> > I'm not sure how to answer that.  lscpu is part of the util-linux package, which
> > is part of any base install.  Theres a variant for BSD, but I'm not sure how
> > common it is there.
> > Neil
> > 
> >> Another acceptable default would be just "-j" without any number.
> >> It would make the number of jobs unlimited.
> 
> I think the best is just use -j as it tries to use the correct number of jobs based on the number of cores, right?
> 
-j with no argument (or -j 0), is sort of, maybe what you want.  With either of
those options, make will just issue jobs as fast as it processes dependencies.
Dependent on how parallel the build is, that can lead to tons of waiting process
(i.e. more than your number of online cpus), which can actually hurt your build
time.

While its fine in los of cases, its not always fine, and with this
implementation you can still opt in to that behavior by setting DPDK_MAKE_JOBS=0

Neil

>
  

> On Jul 20, 2016, at 3:16 PM, Neil Horman <nhorman@tuxdriver.com> wrote:

> 

> On Wed, Jul 20, 2016 at 07:47:32PM +0000, Wiles, Keith wrote:

>> 

>>> On Jul 20, 2016, at 12:48 PM, Neil Horman <nhorman@redhat.com> wrote:

>>> 

>>> On Wed, Jul 20, 2016 at 07:40:49PM +0200, Thomas Monjalon wrote:

>>>> 2016-07-20 13:09, Neil Horman:

>>>>> From: Neil Horman <nhorman@redhat.com>

>>>>> 

>>>>> John Mcnamara and I were discussing enhacing the validate_abi script to build

>>>>> the dpdk tree faster with multiple jobs.  Theres no reason not to do it, so this

>>>>> implements that requirement.  It uses a MAKE_JOBS variable that can be set by

>>>>> the user to limit the job count.  By default the job count is set to the number

>>>>> of online cpus.

>>>> 

>>>> Please could you use the variable name DPDK_MAKE_JOBS?

>>>> This name is already used in scripts/test-build.sh.

>>>> 

>>> Sure

>>> 

>>>>> +if [ -z "$MAKE_JOBS" ]

>>>>> +then

>>>>> +	# This counts the number of cpus on the system

>>>>> +	MAKE_JOBS=`lscpu -p=cpu | grep -v "#" | wc -l`

>>>>> +fi

>>>> 

>>>> Is lscpu common enough?

>>>> 

>>> I'm not sure how to answer that.  lscpu is part of the util-linux package, which

>>> is part of any base install.  Theres a variant for BSD, but I'm not sure how

>>> common it is there.

>>> Neil

>>> 

>>>> Another acceptable default would be just "-j" without any number.

>>>> It would make the number of jobs unlimited.

>> 

>> I think the best is just use -j as it tries to use the correct number of jobs based on the number of cores, right?

>> 

> -j with no argument (or -j 0), is sort of, maybe what you want.  With either of

> those options, make will just issue jobs as fast as it processes dependencies.

> Dependent on how parallel the build is, that can lead to tons of waiting process

> (i.e. more than your number of online cpus), which can actually hurt your build

> time.


I read the manual and looked at the code, which supports your statement. (I think I had some statement on stack overflow and the last time I believe anything on the internet :-) I have not seen a lot of differences in compile times with -j on my system. Mostly I suspect it is the number of paths in the dependency, cores and memory on the system.

I have 72 lcores or 2 sockets, 18 cores per socket. Xeon 2.3Ghz cores.

$ export RTE_TARGET=x86_64-native-linuxapp-gcc 

$ time make install T=${RTE_TARGET}
real	0m59.445s user	0m27.344s sys	0m7.040s

$ time make install T=${RTE_TARGET} -j
real	0m26.584s user	0m14.380s sys	0m5.120s

# Remove the x86_64-native-linuxapp-gcc

$ time make install T=${RTE_TARGET} -j 72
real	0m23.454s user	0m10.832s sys	0m4.664s

$ time make install T=${RTE_TARGET} -j 8
real	0m23.812s user	0m10.672s sys	0m4.276s

cd x86_64-native-linuxapp-gcc
$ make clean
$ time make
real	0m28.539s user	0m9.820s sys	0m3.620s

# Do a make clean between each build.

$ time make -j
real	0m7.217s user	0m6.532s sys	0m2.332s

$ time make -j 8
real	0m8.256s user	0m6.472s sys	0m2.456s

$ time make -j 72
real	0m6.866s user	0m6.184s sys	0m2.216s

Just the real time numbers in the following table.

processes     real Time   depdirs
     no -j             59.4s        Yes
       -j 8             23.8s        Yes
      -j 72            23.5s        Yes
        -j               26.5s        Yes

     no -j             28.5s         No
       -j 8               8.2s         No
      -j 72              6.8s         No
        -j                 7.2s         No

Looks like the depdirs build time on my system:
$ make clean -j
$ rm .depdirs
$ time make -j
real	0m23.734s user	0m11.228s sys	0m4.844s

About 16 seconds, which is not a lot of savings. Now the difference from no -j to -j is a lot, but the difference between -j and -j <cpu_count> is not a huge saving. This leads me back to over engineering the problem when ‘-j’ would work just as well here.

Even on my MacBook Pro i7 system the difference is not that much 1m8s without depdirs build for -j in a VirtualBox with all 4 cores 8G RAM. Compared to 1m13s with -j 4 option.

I just wonder if it makes a lot of sense to use cpuinfo in this given case if it turns out to be -j works with the 80% rule?

On some other project with a lot more files like the FreeBSD or Linux distro, yes it would make a fair amount of real time difference.

Keith

> 

> While its fine in los of cases, its not always fine, and with this

> implementation you can still opt in to that behavior by setting DPDK_MAKE_JOBS=0

> 

> Neil

> 

>>
  

On Wed, Jul 20, 2016 at 10:32:28PM +0000, Wiles, Keith wrote:
> 
> > On Jul 20, 2016, at 3:16 PM, Neil Horman <nhorman@tuxdriver.com> wrote:
> > 
> > On Wed, Jul 20, 2016 at 07:47:32PM +0000, Wiles, Keith wrote:
> >> 
> >>> On Jul 20, 2016, at 12:48 PM, Neil Horman <nhorman@redhat.com> wrote:
> >>> 
> >>> On Wed, Jul 20, 2016 at 07:40:49PM +0200, Thomas Monjalon wrote:
> >>>> 2016-07-20 13:09, Neil Horman:
> >>>>> From: Neil Horman <nhorman@redhat.com>
> >>>>> 
> >>>>> John Mcnamara and I were discussing enhacing the validate_abi script to build
> >>>>> the dpdk tree faster with multiple jobs.  Theres no reason not to do it, so this
> >>>>> implements that requirement.  It uses a MAKE_JOBS variable that can be set by
> >>>>> the user to limit the job count.  By default the job count is set to the number
> >>>>> of online cpus.
> >>>> 
> >>>> Please could you use the variable name DPDK_MAKE_JOBS?
> >>>> This name is already used in scripts/test-build.sh.
> >>>> 
> >>> Sure
> >>> 
> >>>>> +if [ -z "$MAKE_JOBS" ]
> >>>>> +then
> >>>>> +	# This counts the number of cpus on the system
> >>>>> +	MAKE_JOBS=`lscpu -p=cpu | grep -v "#" | wc -l`
> >>>>> +fi
> >>>> 
> >>>> Is lscpu common enough?
> >>>> 
> >>> I'm not sure how to answer that.  lscpu is part of the util-linux package, which
> >>> is part of any base install.  Theres a variant for BSD, but I'm not sure how
> >>> common it is there.
> >>> Neil
> >>> 
> >>>> Another acceptable default would be just "-j" without any number.
> >>>> It would make the number of jobs unlimited.
> >> 
> >> I think the best is just use -j as it tries to use the correct number of jobs based on the number of cores, right?
> >> 
> > -j with no argument (or -j 0), is sort of, maybe what you want.  With either of
> > those options, make will just issue jobs as fast as it processes dependencies.
> > Dependent on how parallel the build is, that can lead to tons of waiting process
> > (i.e. more than your number of online cpus), which can actually hurt your build
> > time.
> 
> I read the manual and looked at the code, which supports your statement. (I think I had some statement on stack overflow and the last time I believe anything on the internet :-) I have not seen a lot of differences in compile times with -j on my system. Mostly I suspect it is the number of paths in the dependency, cores and memory on the system.
> 
> I have 72 lcores or 2 sockets, 18 cores per socket. Xeon 2.3Ghz cores.
> 
> $ export RTE_TARGET=x86_64-native-linuxapp-gcc 
> 
> $ time make install T=${RTE_TARGET}
> real	0m59.445s user	0m27.344s sys	0m7.040s
> 
> $ time make install T=${RTE_TARGET} -j
> real	0m26.584s user	0m14.380s sys	0m5.120s
> 
> # Remove the x86_64-native-linuxapp-gcc
> 
> $ time make install T=${RTE_TARGET} -j 72
> real	0m23.454s user	0m10.832s sys	0m4.664s
> 
> $ time make install T=${RTE_TARGET} -j 8
> real	0m23.812s user	0m10.672s sys	0m4.276s
> 
> cd x86_64-native-linuxapp-gcc
> $ make clean
> $ time make
> real	0m28.539s user	0m9.820s sys	0m3.620s
> 
> # Do a make clean between each build.
> 
> $ time make -j
> real	0m7.217s user	0m6.532s sys	0m2.332s
> 
> $ time make -j 8
> real	0m8.256s user	0m6.472s sys	0m2.456s
> 
> $ time make -j 72
> real	0m6.866s user	0m6.184s sys	0m2.216s
> 
> Just the real time numbers in the following table.
> 
> processes     real Time   depdirs
>      no -j             59.4s        Yes
>        -j 8             23.8s        Yes
>       -j 72            23.5s        Yes
>         -j               26.5s        Yes
> 
>      no -j             28.5s         No
>        -j 8               8.2s         No
>       -j 72              6.8s         No
>         -j                 7.2s         No
> 
> Looks like the depdirs build time on my system:
> $ make clean -j
> $ rm .depdirs
> $ time make -j
> real	0m23.734s user	0m11.228s sys	0m4.844s
> 
> About 16 seconds, which is not a lot of savings. Now the difference from no -j to -j is a lot, but the difference between -j and -j <cpu_count> is not a huge saving. This leads me back to over engineering the problem when ‘-j’ would work just as well here.
> 
> Even on my MacBook Pro i7 system the difference is not that much 1m8s without depdirs build for -j in a VirtualBox with all 4 cores 8G RAM. Compared to 1m13s with -j 4 option.
> 
> I just wonder if it makes a lot of sense to use cpuinfo in this given case if it turns out to be -j works with the 80% rule?
> 
It may, but that seems to be reason to me to just set DPDK_MAKE_JOBS=0, and
you'll get that behavior

Neil

> On some other project with a lot more files like the FreeBSD or Linux distro, yes it would make a fair amount of real time difference.
> 
> Keith
> 
> > 
> > While its fine in los of cases, its not always fine, and with this
> > implementation you can still opt in to that behavior by setting DPDK_MAKE_JOBS=0
> > 
> > Neil
> > 
> >> 
>
  

> On Jul 21, 2016, at 8:54 AM, Neil Horman <nhorman@tuxdriver.com> wrote:

> 

> On Wed, Jul 20, 2016 at 10:32:28PM +0000, Wiles, Keith wrote:

>> 

>>> On Jul 20, 2016, at 3:16 PM, Neil Horman <nhorman@tuxdriver.com> wrote:

>>> 

>>> On Wed, Jul 20, 2016 at 07:47:32PM +0000, Wiles, Keith wrote:

>>>> 

>>>>> On Jul 20, 2016, at 12:48 PM, Neil Horman <nhorman@redhat.com> wrote:

>>>>> 

>>>>> On Wed, Jul 20, 2016 at 07:40:49PM +0200, Thomas Monjalon wrote:

>>>>>> 2016-07-20 13:09, Neil Horman:

>>>>>>> From: Neil Horman <nhorman@redhat.com>

>>>>>>> 

>>>>>>> John Mcnamara and I were discussing enhacing the validate_abi script to build

>>>>>>> the dpdk tree faster with multiple jobs.  Theres no reason not to do it, so this

>>>>>>> implements that requirement.  It uses a MAKE_JOBS variable that can be set by

>>>>>>> the user to limit the job count.  By default the job count is set to the number

>>>>>>> of online cpus.

>>>>>> 

>>>>>> Please could you use the variable name DPDK_MAKE_JOBS?

>>>>>> This name is already used in scripts/test-build.sh.

>>>>>> 

>>>>> Sure

>>>>> 

>>>>>>> +if [ -z "$MAKE_JOBS" ]

>>>>>>> +then

>>>>>>> +	# This counts the number of cpus on the system

>>>>>>> +	MAKE_JOBS=`lscpu -p=cpu | grep -v "#" | wc -l`

>>>>>>> +fi

>>>>>> 

>>>>>> Is lscpu common enough?

>>>>>> 

>>>>> I'm not sure how to answer that.  lscpu is part of the util-linux package, which

>>>>> is part of any base install.  Theres a variant for BSD, but I'm not sure how

>>>>> common it is there.

>>>>> Neil

>>>>> 

>>>>>> Another acceptable default would be just "-j" without any number.

>>>>>> It would make the number of jobs unlimited.

>>>> 

>>>> I think the best is just use -j as it tries to use the correct number of jobs based on the number of cores, right?

>>>> 

>>> -j with no argument (or -j 0), is sort of, maybe what you want.  With either of

>>> those options, make will just issue jobs as fast as it processes dependencies.

>>> Dependent on how parallel the build is, that can lead to tons of waiting process

>>> (i.e. more than your number of online cpus), which can actually hurt your build

>>> time.

>> 

>> I read the manual and looked at the code, which supports your statement. (I think I had some statement on stack overflow and the last time I believe anything on the internet :-) I have not seen a lot of differences in compile times with -j on my system. Mostly I suspect it is the number of paths in the dependency, cores and memory on the system.

>> 

>> I have 72 lcores or 2 sockets, 18 cores per socket. Xeon 2.3Ghz cores.

>> 

>> $ export RTE_TARGET=x86_64-native-linuxapp-gcc 

>> 

>> $ time make install T=${RTE_TARGET}

>> real	0m59.445s user	0m27.344s sys	0m7.040s

>> 

>> $ time make install T=${RTE_TARGET} -j

>> real	0m26.584s user	0m14.380s sys	0m5.120s

>> 

>> # Remove the x86_64-native-linuxapp-gcc

>> 

>> $ time make install T=${RTE_TARGET} -j 72

>> real	0m23.454s user	0m10.832s sys	0m4.664s

>> 

>> $ time make install T=${RTE_TARGET} -j 8

>> real	0m23.812s user	0m10.672s sys	0m4.276s

>> 

>> cd x86_64-native-linuxapp-gcc

>> $ make clean

>> $ time make

>> real	0m28.539s user	0m9.820s sys	0m3.620s

>> 

>> # Do a make clean between each build.

>> 

>> $ time make -j

>> real	0m7.217s user	0m6.532s sys	0m2.332s

>> 

>> $ time make -j 8

>> real	0m8.256s user	0m6.472s sys	0m2.456s

>> 

>> $ time make -j 72

>> real	0m6.866s user	0m6.184s sys	0m2.216s

>> 

>> Just the real time numbers in the following table.

>> 

>> processes     real Time   depdirs

>>     no -j             59.4s        Yes

>>       -j 8             23.8s        Yes

>>      -j 72            23.5s        Yes

>>        -j               26.5s        Yes

>> 

>>     no -j             28.5s         No

>>       -j 8               8.2s         No

>>      -j 72              6.8s         No

>>        -j                 7.2s         No

>> 

>> Looks like the depdirs build time on my system:

>> $ make clean -j

>> $ rm .depdirs

>> $ time make -j

>> real	0m23.734s user	0m11.228s sys	0m4.844s

>> 

>> About 16 seconds, which is not a lot of savings. Now the difference from no -j to -j is a lot, but the difference between -j and -j <cpu_count> is not a huge saving. This leads me back to over engineering the problem when ‘-j’ would work just as well here.

>> 

>> Even on my MacBook Pro i7 system the difference is not that much 1m8s without depdirs build for -j in a VirtualBox with all 4 cores 8G RAM. Compared to 1m13s with -j 4 option.

>> 

>> I just wonder if it makes a lot of sense to use cpuinfo in this given case if it turns out to be -j works with the 80% rule?

>> 

> It may, but that seems to be reason to me to just set DPDK_MAKE_JOBS=0, and

> you'll get that behavior


Just to be sure, ‘make -j 0’ is not a valid argument to the -j option. It looks like you have to do ‘-j’ or ‘-j N’ or no option where N != 0

I think we just use -j which gets us the 80% rule and the best performance without counting cores.

> 

> Neil

> 

>> On some other project with a lot more files like the FreeBSD or Linux distro, yes it would make a fair amount of real time difference.

>> 

>> Keith

>> 

>>> 

>>> While its fine in los of cases, its not always fine, and with this

>>> implementation you can still opt in to that behavior by setting DPDK_MAKE_JOBS=0

>>> 

>>> Neil
  

On Thu, Jul 21, 2016 at 02:09:19PM +0000, Wiles, Keith wrote:
> 
> > On Jul 21, 2016, at 8:54 AM, Neil Horman <nhorman@tuxdriver.com> wrote:
> > 
> > On Wed, Jul 20, 2016 at 10:32:28PM +0000, Wiles, Keith wrote:
> >> 
> >>> On Jul 20, 2016, at 3:16 PM, Neil Horman <nhorman@tuxdriver.com> wrote:
> >>> 
> >>> On Wed, Jul 20, 2016 at 07:47:32PM +0000, Wiles, Keith wrote:
> >>>> 
> >>>>> On Jul 20, 2016, at 12:48 PM, Neil Horman <nhorman@redhat.com> wrote:
> >>>>> 
> >>>>> On Wed, Jul 20, 2016 at 07:40:49PM +0200, Thomas Monjalon wrote:
> >>>>>> 2016-07-20 13:09, Neil Horman:
> >>>>>>> From: Neil Horman <nhorman@redhat.com>
> >>>>>>> 
> >>>>>>> John Mcnamara and I were discussing enhacing the validate_abi script to build
> >>>>>>> the dpdk tree faster with multiple jobs.  Theres no reason not to do it, so this
> >>>>>>> implements that requirement.  It uses a MAKE_JOBS variable that can be set by
> >>>>>>> the user to limit the job count.  By default the job count is set to the number
> >>>>>>> of online cpus.
> >>>>>> 
> >>>>>> Please could you use the variable name DPDK_MAKE_JOBS?
> >>>>>> This name is already used in scripts/test-build.sh.
> >>>>>> 
> >>>>> Sure
> >>>>> 
> >>>>>>> +if [ -z "$MAKE_JOBS" ]
> >>>>>>> +then
> >>>>>>> +	# This counts the number of cpus on the system
> >>>>>>> +	MAKE_JOBS=`lscpu -p=cpu | grep -v "#" | wc -l`
> >>>>>>> +fi
> >>>>>> 
> >>>>>> Is lscpu common enough?
> >>>>>> 
> >>>>> I'm not sure how to answer that.  lscpu is part of the util-linux package, which
> >>>>> is part of any base install.  Theres a variant for BSD, but I'm not sure how
> >>>>> common it is there.
> >>>>> Neil
> >>>>> 
> >>>>>> Another acceptable default would be just "-j" without any number.
> >>>>>> It would make the number of jobs unlimited.
> >>>> 
> >>>> I think the best is just use -j as it tries to use the correct number of jobs based on the number of cores, right?
> >>>> 
> >>> -j with no argument (or -j 0), is sort of, maybe what you want.  With either of
> >>> those options, make will just issue jobs as fast as it processes dependencies.
> >>> Dependent on how parallel the build is, that can lead to tons of waiting process
> >>> (i.e. more than your number of online cpus), which can actually hurt your build
> >>> time.
> >> 
> >> I read the manual and looked at the code, which supports your statement. (I think I had some statement on stack overflow and the last time I believe anything on the internet :-) I have not seen a lot of differences in compile times with -j on my system. Mostly I suspect it is the number of paths in the dependency, cores and memory on the system.
> >> 
> >> I have 72 lcores or 2 sockets, 18 cores per socket. Xeon 2.3Ghz cores.
> >> 
> >> $ export RTE_TARGET=x86_64-native-linuxapp-gcc 
> >> 
> >> $ time make install T=${RTE_TARGET}
> >> real	0m59.445s user	0m27.344s sys	0m7.040s
> >> 
> >> $ time make install T=${RTE_TARGET} -j
> >> real	0m26.584s user	0m14.380s sys	0m5.120s
> >> 
> >> # Remove the x86_64-native-linuxapp-gcc
> >> 
> >> $ time make install T=${RTE_TARGET} -j 72
> >> real	0m23.454s user	0m10.832s sys	0m4.664s
> >> 
> >> $ time make install T=${RTE_TARGET} -j 8
> >> real	0m23.812s user	0m10.672s sys	0m4.276s
> >> 
> >> cd x86_64-native-linuxapp-gcc
> >> $ make clean
> >> $ time make
> >> real	0m28.539s user	0m9.820s sys	0m3.620s
> >> 
> >> # Do a make clean between each build.
> >> 
> >> $ time make -j
> >> real	0m7.217s user	0m6.532s sys	0m2.332s
> >> 
> >> $ time make -j 8
> >> real	0m8.256s user	0m6.472s sys	0m2.456s
> >> 
> >> $ time make -j 72
> >> real	0m6.866s user	0m6.184s sys	0m2.216s
> >> 
> >> Just the real time numbers in the following table.
> >> 
> >> processes     real Time   depdirs
> >>     no -j             59.4s        Yes
> >>       -j 8             23.8s        Yes
> >>      -j 72            23.5s        Yes
> >>        -j               26.5s        Yes
> >> 
> >>     no -j             28.5s         No
> >>       -j 8               8.2s         No
> >>      -j 72              6.8s         No
> >>        -j                 7.2s         No
> >> 
> >> Looks like the depdirs build time on my system:
> >> $ make clean -j
> >> $ rm .depdirs
> >> $ time make -j
> >> real	0m23.734s user	0m11.228s sys	0m4.844s
> >> 
> >> About 16 seconds, which is not a lot of savings. Now the difference from no -j to -j is a lot, but the difference between -j and -j <cpu_count> is not a huge saving. This leads me back to over engineering the problem when ‘-j’ would work just as well here.
> >> 
> >> Even on my MacBook Pro i7 system the difference is not that much 1m8s without depdirs build for -j in a VirtualBox with all 4 cores 8G RAM. Compared to 1m13s with -j 4 option.
> >> 
> >> I just wonder if it makes a lot of sense to use cpuinfo in this given case if it turns out to be -j works with the 80% rule?
> >> 
> > It may, but that seems to be reason to me to just set DPDK_MAKE_JOBS=0, and
> > you'll get that behavior
> 
> Just to be sure, ‘make -j 0’ is not a valid argument to the -j option. It looks like you have to do ‘-j’ or ‘-j N’ or no option where N != 0
> 
> I think we just use -j which gets us the 80% rule and the best performance without counting cores.
> 
Thats odd, specifying 0 works for me.  If it doesn't for you, specify $MAX_INT
or some other huge number would be comparable

Neil

> > 
> > Neil
> > 
> >> On some other project with a lot more files like the FreeBSD or Linux distro, yes it would make a fair amount of real time difference.
> >> 
> >> Keith
> >> 
> >>> 
> >>> While its fine in los of cases, its not always fine, and with this
> >>> implementation you can still opt in to that behavior by setting DPDK_MAKE_JOBS=0
> >>> 
> >>> Neil
>
  

> On Jul 21, 2016, at 10:06 AM, Neil Horman <nhorman@redhat.com> wrote:

> 

> On Thu, Jul 21, 2016 at 02:09:19PM +0000, Wiles, Keith wrote:

>> 

>>> On Jul 21, 2016, at 8:54 AM, Neil Horman <nhorman@tuxdriver.com> wrote:

>>> 

>>> On Wed, Jul 20, 2016 at 10:32:28PM +0000, Wiles, Keith wrote:

>>>> 

>>>>> On Jul 20, 2016, at 3:16 PM, Neil Horman <nhorman@tuxdriver.com> wrote:

>>>>> 

>>>>> On Wed, Jul 20, 2016 at 07:47:32PM +0000, Wiles, Keith wrote:

>>>>>> 

>>>>>>> On Jul 20, 2016, at 12:48 PM, Neil Horman <nhorman@redhat.com> wrote:

>>>>>>> 

>>>>>>> On Wed, Jul 20, 2016 at 07:40:49PM +0200, Thomas Monjalon wrote:

>>>>>>>> 2016-07-20 13:09, Neil Horman:

>>>>>>>>> From: Neil Horman <nhorman@redhat.com>

>>>>>>>>> 

>>>>>>>>> John Mcnamara and I were discussing enhacing the validate_abi script to build

>>>>>>>>> the dpdk tree faster with multiple jobs.  Theres no reason not to do it, so this

>>>>>>>>> implements that requirement.  It uses a MAKE_JOBS variable that can be set by

>>>>>>>>> the user to limit the job count.  By default the job count is set to the number

>>>>>>>>> of online cpus.

>>>>>>>> 

>>>>>>>> Please could you use the variable name DPDK_MAKE_JOBS?

>>>>>>>> This name is already used in scripts/test-build.sh.

>>>>>>>> 

>>>>>>> Sure

>>>>>>> 

>>>>>>>>> +if [ -z "$MAKE_JOBS" ]

>>>>>>>>> +then

>>>>>>>>> +	# This counts the number of cpus on the system

>>>>>>>>> +	MAKE_JOBS=`lscpu -p=cpu | grep -v "#" | wc -l`

>>>>>>>>> +fi

>>>>>>>> 

>>>>>>>> Is lscpu common enough?

>>>>>>>> 

>>>>>>> I'm not sure how to answer that.  lscpu is part of the util-linux package, which

>>>>>>> is part of any base install.  Theres a variant for BSD, but I'm not sure how

>>>>>>> common it is there.

>>>>>>> Neil

>>>>>>> 

>>>>>>>> Another acceptable default would be just "-j" without any number.

>>>>>>>> It would make the number of jobs unlimited.

>>>>>> 

>>>>>> I think the best is just use -j as it tries to use the correct number of jobs based on the number of cores, right?

>>>>>> 

>>>>> -j with no argument (or -j 0), is sort of, maybe what you want.  With either of

>>>>> those options, make will just issue jobs as fast as it processes dependencies.

>>>>> Dependent on how parallel the build is, that can lead to tons of waiting process

>>>>> (i.e. more than your number of online cpus), which can actually hurt your build

>>>>> time.

>>>> 

>>>> I read the manual and looked at the code, which supports your statement. (I think I had some statement on stack overflow and the last time I believe anything on the internet :-) I have not seen a lot of differences in compile times with -j on my system. Mostly I suspect it is the number of paths in the dependency, cores and memory on the system.

>>>> 

>>>> I have 72 lcores or 2 sockets, 18 cores per socket. Xeon 2.3Ghz cores.

>>>> 

>>>> $ export RTE_TARGET=x86_64-native-linuxapp-gcc 

>>>> 

>>>> $ time make install T=${RTE_TARGET}

>>>> real	0m59.445s user	0m27.344s sys	0m7.040s

>>>> 

>>>> $ time make install T=${RTE_TARGET} -j

>>>> real	0m26.584s user	0m14.380s sys	0m5.120s

>>>> 

>>>> # Remove the x86_64-native-linuxapp-gcc

>>>> 

>>>> $ time make install T=${RTE_TARGET} -j 72

>>>> real	0m23.454s user	0m10.832s sys	0m4.664s

>>>> 

>>>> $ time make install T=${RTE_TARGET} -j 8

>>>> real	0m23.812s user	0m10.672s sys	0m4.276s

>>>> 

>>>> cd x86_64-native-linuxapp-gcc

>>>> $ make clean

>>>> $ time make

>>>> real	0m28.539s user	0m9.820s sys	0m3.620s

>>>> 

>>>> # Do a make clean between each build.

>>>> 

>>>> $ time make -j

>>>> real	0m7.217s user	0m6.532s sys	0m2.332s

>>>> 

>>>> $ time make -j 8

>>>> real	0m8.256s user	0m6.472s sys	0m2.456s

>>>> 

>>>> $ time make -j 72

>>>> real	0m6.866s user	0m6.184s sys	0m2.216s

>>>> 

>>>> Just the real time numbers in the following table.

>>>> 

>>>> processes     real Time   depdirs

>>>>    no -j             59.4s        Yes

>>>>      -j 8             23.8s        Yes

>>>>     -j 72            23.5s        Yes

>>>>       -j               26.5s        Yes

>>>> 

>>>>    no -j             28.5s         No

>>>>      -j 8               8.2s         No

>>>>     -j 72              6.8s         No

>>>>       -j                 7.2s         No

>>>> 

>>>> Looks like the depdirs build time on my system:

>>>> $ make clean -j

>>>> $ rm .depdirs

>>>> $ time make -j

>>>> real	0m23.734s user	0m11.228s sys	0m4.844s

>>>> 

>>>> About 16 seconds, which is not a lot of savings. Now the difference from no -j to -j is a lot, but the difference between -j and -j <cpu_count> is not a huge saving. This leads me back to over engineering the problem when ‘-j’ would work just as well here.

>>>> 

>>>> Even on my MacBook Pro i7 system the difference is not that much 1m8s without depdirs build for -j in a VirtualBox with all 4 cores 8G RAM. Compared to 1m13s with -j 4 option.

>>>> 

>>>> I just wonder if it makes a lot of sense to use cpuinfo in this given case if it turns out to be -j works with the 80% rule?

>>>> 

>>> It may, but that seems to be reason to me to just set DPDK_MAKE_JOBS=0, and

>>> you'll get that behavior

>> 

>> Just to be sure, ‘make -j 0’ is not a valid argument to the -j option. It looks like you have to do ‘-j’ or ‘-j N’ or no option where N != 0

>> 

>> I think we just use -j which gets us the 80% rule and the best performance without counting cores.

>> 

> Thats odd, specifying 0 works for me.  If it doesn't for you, specify $MAX_INT

> or some other huge number would be comparable


rkwiles@supermicro (master):~/.../dpdk/x86_64-native-linuxapp-gcc$ make --version
GNU Make 4.1
Built for x86_64-pc-linux-gnu
Copyright (C) 1988-2014 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.

rkwiles@supermicro (master):~/.../dpdk/x86_64-native-linuxapp-gcc$ make -j 0
make: the '-j' option requires a positive integer argument

rkwiles@supermicro (master):~/.../dpdk/x86_64-native-linuxapp-gcc$ lsb_release -a
No LSB modules are available.
Distributor ID:	Ubuntu
Description:	Ubuntu 16.04.1 LTS
Release:	16.04
Codename:	xenial

> 

> Neil

> 

>>> 

>>> Neil

>>> 

>>>> On some other project with a lot more files like the FreeBSD or Linux distro, yes it would make a fair amount of real time difference.

>>>> 

>>>> Keith

>>>> 

>>>>> 

>>>>> While its fine in los of cases, its not always fine, and with this

>>>>> implementation you can still opt in to that behavior by setting DPDK_MAKE_JOBS=0

>>>>> 

>>>>> Neil
  

On Thu, Jul 21, 2016 at 03:22:45PM +0000, Wiles, Keith wrote:
> 
> > On Jul 21, 2016, at 10:06 AM, Neil Horman <nhorman@redhat.com> wrote:
> > 
> > On Thu, Jul 21, 2016 at 02:09:19PM +0000, Wiles, Keith wrote:
> >> 
> >>> On Jul 21, 2016, at 8:54 AM, Neil Horman <nhorman@tuxdriver.com> wrote:
> >>> 
> >>> On Wed, Jul 20, 2016 at 10:32:28PM +0000, Wiles, Keith wrote:
> >>>> 
> >>>>> On Jul 20, 2016, at 3:16 PM, Neil Horman <nhorman@tuxdriver.com> wrote:
> >>>>> 
> >>>>> On Wed, Jul 20, 2016 at 07:47:32PM +0000, Wiles, Keith wrote:
> >>>>>> 
> >>>>>>> On Jul 20, 2016, at 12:48 PM, Neil Horman <nhorman@redhat.com> wrote:
> >>>>>>> 
> >>>>>>> On Wed, Jul 20, 2016 at 07:40:49PM +0200, Thomas Monjalon wrote:
> >>>>>>>> 2016-07-20 13:09, Neil Horman:
> >>>>>>>>> From: Neil Horman <nhorman@redhat.com>
> >>>>>>>>> 
> >>>>>>>>> John Mcnamara and I were discussing enhacing the validate_abi script to build
> >>>>>>>>> the dpdk tree faster with multiple jobs.  Theres no reason not to do it, so this
> >>>>>>>>> implements that requirement.  It uses a MAKE_JOBS variable that can be set by
> >>>>>>>>> the user to limit the job count.  By default the job count is set to the number
> >>>>>>>>> of online cpus.
> >>>>>>>> 
> >>>>>>>> Please could you use the variable name DPDK_MAKE_JOBS?
> >>>>>>>> This name is already used in scripts/test-build.sh.
> >>>>>>>> 
> >>>>>>> Sure
> >>>>>>> 
> >>>>>>>>> +if [ -z "$MAKE_JOBS" ]
> >>>>>>>>> +then
> >>>>>>>>> +	# This counts the number of cpus on the system
> >>>>>>>>> +	MAKE_JOBS=`lscpu -p=cpu | grep -v "#" | wc -l`
> >>>>>>>>> +fi
> >>>>>>>> 
> >>>>>>>> Is lscpu common enough?
> >>>>>>>> 
> >>>>>>> I'm not sure how to answer that.  lscpu is part of the util-linux package, which
> >>>>>>> is part of any base install.  Theres a variant for BSD, but I'm not sure how
> >>>>>>> common it is there.
> >>>>>>> Neil
> >>>>>>> 
> >>>>>>>> Another acceptable default would be just "-j" without any number.
> >>>>>>>> It would make the number of jobs unlimited.
> >>>>>> 
> >>>>>> I think the best is just use -j as it tries to use the correct number of jobs based on the number of cores, right?
> >>>>>> 
> >>>>> -j with no argument (or -j 0), is sort of, maybe what you want.  With either of
> >>>>> those options, make will just issue jobs as fast as it processes dependencies.
> >>>>> Dependent on how parallel the build is, that can lead to tons of waiting process
> >>>>> (i.e. more than your number of online cpus), which can actually hurt your build
> >>>>> time.
> >>>> 
> >>>> I read the manual and looked at the code, which supports your statement. (I think I had some statement on stack overflow and the last time I believe anything on the internet :-) I have not seen a lot of differences in compile times with -j on my system. Mostly I suspect it is the number of paths in the dependency, cores and memory on the system.
> >>>> 
> >>>> I have 72 lcores or 2 sockets, 18 cores per socket. Xeon 2.3Ghz cores.
> >>>> 
> >>>> $ export RTE_TARGET=x86_64-native-linuxapp-gcc 
> >>>> 
> >>>> $ time make install T=${RTE_TARGET}
> >>>> real	0m59.445s user	0m27.344s sys	0m7.040s
> >>>> 
> >>>> $ time make install T=${RTE_TARGET} -j
> >>>> real	0m26.584s user	0m14.380s sys	0m5.120s
> >>>> 
> >>>> # Remove the x86_64-native-linuxapp-gcc
> >>>> 
> >>>> $ time make install T=${RTE_TARGET} -j 72
> >>>> real	0m23.454s user	0m10.832s sys	0m4.664s
> >>>> 
> >>>> $ time make install T=${RTE_TARGET} -j 8
> >>>> real	0m23.812s user	0m10.672s sys	0m4.276s
> >>>> 
> >>>> cd x86_64-native-linuxapp-gcc
> >>>> $ make clean
> >>>> $ time make
> >>>> real	0m28.539s user	0m9.820s sys	0m3.620s
> >>>> 
> >>>> # Do a make clean between each build.
> >>>> 
> >>>> $ time make -j
> >>>> real	0m7.217s user	0m6.532s sys	0m2.332s
> >>>> 
> >>>> $ time make -j 8
> >>>> real	0m8.256s user	0m6.472s sys	0m2.456s
> >>>> 
> >>>> $ time make -j 72
> >>>> real	0m6.866s user	0m6.184s sys	0m2.216s
> >>>> 
> >>>> Just the real time numbers in the following table.
> >>>> 
> >>>> processes     real Time   depdirs
> >>>>    no -j             59.4s        Yes
> >>>>      -j 8             23.8s        Yes
> >>>>     -j 72            23.5s        Yes
> >>>>       -j               26.5s        Yes
> >>>> 
> >>>>    no -j             28.5s         No
> >>>>      -j 8               8.2s         No
> >>>>     -j 72              6.8s         No
> >>>>       -j                 7.2s         No
> >>>> 
> >>>> Looks like the depdirs build time on my system:
> >>>> $ make clean -j
> >>>> $ rm .depdirs
> >>>> $ time make -j
> >>>> real	0m23.734s user	0m11.228s sys	0m4.844s
> >>>> 
> >>>> About 16 seconds, which is not a lot of savings. Now the difference from no -j to -j is a lot, but the difference between -j and -j <cpu_count> is not a huge saving. This leads me back to over engineering the problem when ‘-j’ would work just as well here.
> >>>> 
> >>>> Even on my MacBook Pro i7 system the difference is not that much 1m8s without depdirs build for -j in a VirtualBox with all 4 cores 8G RAM. Compared to 1m13s with -j 4 option.
> >>>> 
> >>>> I just wonder if it makes a lot of sense to use cpuinfo in this given case if it turns out to be -j works with the 80% rule?
> >>>> 
> >>> It may, but that seems to be reason to me to just set DPDK_MAKE_JOBS=0, and
> >>> you'll get that behavior
> >> 
> >> Just to be sure, ‘make -j 0’ is not a valid argument to the -j option. It looks like you have to do ‘-j’ or ‘-j N’ or no option where N != 0
> >> 
> >> I think we just use -j which gets us the 80% rule and the best performance without counting cores.
> >> 
> > Thats odd, specifying 0 works for me.  If it doesn't for you, specify $MAX_INT
> > or some other huge number would be comparable
> 
> rkwiles@supermicro (master):~/.../dpdk/x86_64-native-linuxapp-gcc$ make --version
> GNU Make 4.1
> Built for x86_64-pc-linux-gnu
> Copyright (C) 1988-2014 Free Software Foundation, Inc.
> License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
> This is free software: you are free to change and redistribute it.
> There is NO WARRANTY, to the extent permitted by law.
> 
> rkwiles@supermicro (master):~/.../dpdk/x86_64-native-linuxapp-gcc$ make -j 0
> make: the '-j' option requires a positive integer argument
> 
> rkwiles@supermicro (master):~/.../dpdk/x86_64-native-linuxapp-gcc$ lsb_release -a
> No LSB modules are available.
> Distributor ID:	Ubuntu
> Description:	Ubuntu 16.04.1 LTS
> Release:	16.04
> Codename:	xenial
> 
I'm not saying your variant doesn't work, only that my copy of make does, but
its possible that I have some alternately patched version (I used to fix make
bugs way back when, so I may have an impure copy).  Regardless, my comment is
still valid, if you want to have unlimited jobs, you can just export
DPDK_MAKE_JOBS=<some very large number>

Neil

> > 
> > Neil
> > 
> >>> 
> >>> Neil
> >>> 
> >>>> On some other project with a lot more files like the FreeBSD or Linux distro, yes it would make a fair amount of real time difference.
> >>>> 
> >>>> Keith
> >>>> 
> >>>>> 
> >>>>> While its fine in los of cases, its not always fine, and with this
> >>>>> implementation you can still opt in to that behavior by setting DPDK_MAKE_JOBS=0
> >>>>> 
> >>>>> Neil
>
  

Sent from my iPhone

> On Jul 21, 2016, at 1:34 PM, Neil Horman <nhorman@redhat.com> wrote:
> 
>> On Thu, Jul 21, 2016 at 03:22:45PM +0000, Wiles, Keith wrote:
>> 
>>> On Jul 21, 2016, at 10:06 AM, Neil Horman <nhorman@redhat.com> wrote:
>>> 
>>> On Thu, Jul 21, 2016 at 02:09:19PM +0000, Wiles, Keith wrote:
>>>> 
>>>>> On Jul 21, 2016, at 8:54 AM, Neil Horman <nhorman@tuxdriver.com> wrote:
>>>>> 
>>>>> On Wed, Jul 20, 2016 at 10:32:28PM +0000, Wiles, Keith wrote:
>>>>>> 
>>>>>>> On Jul 20, 2016, at 3:16 PM, Neil Horman <nhorman@tuxdriver.com> wrote:
>>>>>>> 
>>>>>>> On Wed, Jul 20, 2016 at 07:47:32PM +0000, Wiles, Keith wrote:
>>>>>>>> 
>>>>>>>>> On Jul 20, 2016, at 12:48 PM, Neil Horman <nhorman@redhat.com> wrote:
>>>>>>>>> 
>>>>>>>>> On Wed, Jul 20, 2016 at 07:40:49PM +0200, Thomas Monjalon wrote:
>>>>>>>>>> 2016-07-20 13:09, Neil Horman:
>>>>>>>>>>> From: Neil Horman <nhorman@redhat.com>
>>>>>>>>>>> 
>>>>>>>>>>> John Mcnamara and I were discussing enhacing the validate_abi script to build
>>>>>>>>>>> the dpdk tree faster with multiple jobs.  Theres no reason not to do it, so this
>>>>>>>>>>> implements that requirement.  It uses a MAKE_JOBS variable that can be set by
>>>>>>>>>>> the user to limit the job count.  By default the job count is set to the number
>>>>>>>>>>> of online cpus.
>>>>>>>>>> 
>>>>>>>>>> Please could you use the variable name DPDK_MAKE_JOBS?
>>>>>>>>>> This name is already used in scripts/test-build.sh.
>>>>>>>>> Sure
>>>>>>>>> 
>>>>>>>>>>> +if [ -z "$MAKE_JOBS" ]
>>>>>>>>>>> +then
>>>>>>>>>>> +    # This counts the number of cpus on the system
>>>>>>>>>>> +    MAKE_JOBS=`lscpu -p=cpu | grep -v "#" | wc -l`
>>>>>>>>>>> +fi
>>>>>>>>>> 
>>>>>>>>>> Is lscpu common enough?
>>>>>>>>> I'm not sure how to answer that.  lscpu is part of the util-linux package, which
>>>>>>>>> is part of any base install.  Theres a variant for BSD, but I'm not sure how
>>>>>>>>> common it is there.
>>>>>>>>> Neil
>>>>>>>>> 
>>>>>>>>>> Another acceptable default would be just "-j" without any number.
>>>>>>>>>> It would make the number of jobs unlimited.
>>>>>>>> 
>>>>>>>> I think the best is just use -j as it tries to use the correct number of jobs based on the number of cores, right?
>>>>>>> -j with no argument (or -j 0), is sort of, maybe what you want.  With either of
>>>>>>> those options, make will just issue jobs as fast as it processes dependencies.
>>>>>>> Dependent on how parallel the build is, that can lead to tons of waiting process
>>>>>>> (i.e. more than your number of online cpus), which can actually hurt your build
>>>>>>> time.
>>>>>> 
>>>>>> I read the manual and looked at the code, which supports your statement. (I think I had some statement on stack overflow and the last time I believe anything on the internet :-) I have not seen a lot of differences in compile times with -j on my system. Mostly I suspect it is the number of paths in the dependency, cores and memory on the system.
>>>>>> 
>>>>>> I have 72 lcores or 2 sockets, 18 cores per socket. Xeon 2.3Ghz cores.
>>>>>> 
>>>>>> $ export RTE_TARGET=x86_64-native-linuxapp-gcc 
>>>>>> 
>>>>>> $ time make install T=${RTE_TARGET}
>>>>>> real    0m59.445s user    0m27.344s sys    0m7.040s
>>>>>> 
>>>>>> $ time make install T=${RTE_TARGET} -j
>>>>>> real    0m26.584s user    0m14.380s sys    0m5.120s
>>>>>> 
>>>>>> # Remove the x86_64-native-linuxapp-gcc
>>>>>> 
>>>>>> $ time make install T=${RTE_TARGET} -j 72
>>>>>> real    0m23.454s user    0m10.832s sys    0m4.664s
>>>>>> 
>>>>>> $ time make install T=${RTE_TARGET} -j 8
>>>>>> real    0m23.812s user    0m10.672s sys    0m4.276s
>>>>>> 
>>>>>> cd x86_64-native-linuxapp-gcc
>>>>>> $ make clean
>>>>>> $ time make
>>>>>> real    0m28.539s user    0m9.820s sys    0m3.620s
>>>>>> 
>>>>>> # Do a make clean between each build.
>>>>>> 
>>>>>> $ time make -j
>>>>>> real    0m7.217s user    0m6.532s sys    0m2.332s
>>>>>> 
>>>>>> $ time make -j 8
>>>>>> real    0m8.256s user    0m6.472s sys    0m2.456s
>>>>>> 
>>>>>> $ time make -j 72
>>>>>> real    0m6.866s user    0m6.184s sys    0m2.216s
>>>>>> 
>>>>>> Just the real time numbers in the following table.
>>>>>> 
>>>>>> processes     real Time   depdirs
>>>>>>   no -j             59.4s        Yes
>>>>>>     -j 8             23.8s        Yes
>>>>>>    -j 72            23.5s        Yes
>>>>>>      -j               26.5s        Yes
>>>>>> 
>>>>>>   no -j             28.5s         No
>>>>>>     -j 8               8.2s         No
>>>>>>    -j 72              6.8s         No
>>>>>>      -j                 7.2s         No
>>>>>> 
>>>>>> Looks like the depdirs build time on my system:
>>>>>> $ make clean -j
>>>>>> $ rm .depdirs
>>>>>> $ time make -j
>>>>>> real    0m23.734s user    0m11.228s sys    0m4.844s
>>>>>> 
>>>>>> About 16 seconds, which is not a lot of savings. Now the difference from no -j to -j is a lot, but the difference between -j and -j <cpu_count> is not a huge saving. This leads me back to over engineering the problem when ‘-j’ would work just as well here.
>>>>>> 
>>>>>> Even on my MacBook Pro i7 system the difference is not that much 1m8s without depdirs build for -j in a VirtualBox with all 4 cores 8G RAM. Compared to 1m13s with -j 4 option.
>>>>>> 
>>>>>> I just wonder if it makes a lot of sense to use cpuinfo in this given case if it turns out to be -j works with the 80% rule?
>>>>> It may, but that seems to be reason to me to just set DPDK_MAKE_JOBS=0, and
>>>>> you'll get that behavior
>>>> 
>>>> Just to be sure, ‘make -j 0’ is not a valid argument to the -j option. It looks like you have to do ‘-j’ or ‘-j N’ or no option where N != 0
>>>> 
>>>> I think we just use -j which gets us the 80% rule and the best performance without counting cores.
>>> Thats odd, specifying 0 works for me.  If it doesn't for you, specify $MAX_INT
>>> or some other huge number would be comparable
>> 
>> rkwiles@supermicro (master):~/.../dpdk/x86_64-native-linuxapp-gcc$ make --version
>> GNU Make 4.1
>> Built for x86_64-pc-linux-gnu
>> Copyright (C) 1988-2014 Free Software Foundation, Inc.
>> License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
>> This is free software: you are free to change and redistribute it.
>> There is NO WARRANTY, to the extent permitted by law.
>> 
>> rkwiles@supermicro (master):~/.../dpdk/x86_64-native-linuxapp-gcc$ make -j 0
>> make: the '-j' option requires a positive integer argument
>> 
>> rkwiles@supermicro (master):~/.../dpdk/x86_64-native-linuxapp-gcc$ lsb_release -a
>> No LSB modules are available.
>> Distributor ID:    Ubuntu
>> Description:    Ubuntu 16.04.1 LTS
>> Release:    16.04
>> Codename:    xenial
> I'm not saying your variant doesn't work, only that my copy of make does, but
> its possible that I have some alternately patched version (I used to fix make
> bugs way back when, so I may have an impure copy).  Regardless, my comment is
> still valid, if you want to have unlimited jobs, you can just export
> DPDK_MAKE_JOBS=<some very large number>

Neil

Your modified copy of make has no bearing on the topic we are taking about customers using dpdk in standard distros right?

Seems odd to me to send this out with 0 or lspci as it may fail because of no lspci and will fail on all Ubuntu systems. 

If we ship with 1 then why even bother the adding code and if I have to edit the file or some other method to get better compile performance then why bother as well.

Setting the value to some large number does not make any sense to me and if I have to edit file every time or maintain a patch just seems silly. 

It just seems easier to set it to -j and not use lspci at all. This way we all win as I am not following your logic at all.

Keith
> 
> Neil
> 
>>> 
>>> Neil
>>> 
>>>>> 
>>>>> Neil
>>>>> 
>>>>>> On some other project with a lot more files like the FreeBSD or Linux distro, yes it would make a fair amount of real time difference.
>>>>>> 
>>>>>> Keith
>>>>>> 
>>>>>>> 
>>>>>>> While its fine in los of cases, its not always fine, and with this
>>>>>>> implementation you can still opt in to that behavior by setting DPDK_MAKE_JOBS=0
>>>>>>> 
>>>>>>> Neil
>>
  

On Sun, Jul 24, 2016 at 06:08:00PM +0000, Wiles, Keith wrote:
> 
> 
> Sent from my iPhone
> 
> > On Jul 21, 2016, at 1:34 PM, Neil Horman <nhorman@redhat.com> wrote:
> > 
> >> On Thu, Jul 21, 2016 at 03:22:45PM +0000, Wiles, Keith wrote:
> >> 
> >>> On Jul 21, 2016, at 10:06 AM, Neil Horman <nhorman@redhat.com> wrote:
> >>> 
> >>> On Thu, Jul 21, 2016 at 02:09:19PM +0000, Wiles, Keith wrote:
> >>>> 
> >>>>> On Jul 21, 2016, at 8:54 AM, Neil Horman <nhorman@tuxdriver.com> wrote:
> >>>>> 
> >>>>> On Wed, Jul 20, 2016 at 10:32:28PM +0000, Wiles, Keith wrote:
> >>>>>> 
> >>>>>>> On Jul 20, 2016, at 3:16 PM, Neil Horman <nhorman@tuxdriver.com> wrote:
> >>>>>>> 
> >>>>>>> On Wed, Jul 20, 2016 at 07:47:32PM +0000, Wiles, Keith wrote:
> >>>>>>>> 
> >>>>>>>>> On Jul 20, 2016, at 12:48 PM, Neil Horman <nhorman@redhat.com> wrote:
> >>>>>>>>> 
> >>>>>>>>> On Wed, Jul 20, 2016 at 07:40:49PM +0200, Thomas Monjalon wrote:
> >>>>>>>>>> 2016-07-20 13:09, Neil Horman:
> >>>>>>>>>>> From: Neil Horman <nhorman@redhat.com>
> >>>>>>>>>>> 
> >>>>>>>>>>> John Mcnamara and I were discussing enhacing the validate_abi script to build
> >>>>>>>>>>> the dpdk tree faster with multiple jobs.  Theres no reason not to do it, so this
> >>>>>>>>>>> implements that requirement.  It uses a MAKE_JOBS variable that can be set by
> >>>>>>>>>>> the user to limit the job count.  By default the job count is set to the number
> >>>>>>>>>>> of online cpus.
> >>>>>>>>>> 
> >>>>>>>>>> Please could you use the variable name DPDK_MAKE_JOBS?
> >>>>>>>>>> This name is already used in scripts/test-build.sh.
> >>>>>>>>> Sure
> >>>>>>>>> 
> >>>>>>>>>>> +if [ -z "$MAKE_JOBS" ]
> >>>>>>>>>>> +then
> >>>>>>>>>>> +    # This counts the number of cpus on the system
> >>>>>>>>>>> +    MAKE_JOBS=`lscpu -p=cpu | grep -v "#" | wc -l`
> >>>>>>>>>>> +fi
> >>>>>>>>>> 
> >>>>>>>>>> Is lscpu common enough?
> >>>>>>>>> I'm not sure how to answer that.  lscpu is part of the util-linux package, which
> >>>>>>>>> is part of any base install.  Theres a variant for BSD, but I'm not sure how
> >>>>>>>>> common it is there.
> >>>>>>>>> Neil
> >>>>>>>>> 
> >>>>>>>>>> Another acceptable default would be just "-j" without any number.
> >>>>>>>>>> It would make the number of jobs unlimited.
> >>>>>>>> 
> >>>>>>>> I think the best is just use -j as it tries to use the correct number of jobs based on the number of cores, right?
> >>>>>>> -j with no argument (or -j 0), is sort of, maybe what you want.  With either of
> >>>>>>> those options, make will just issue jobs as fast as it processes dependencies.
> >>>>>>> Dependent on how parallel the build is, that can lead to tons of waiting process
> >>>>>>> (i.e. more than your number of online cpus), which can actually hurt your build
> >>>>>>> time.
> >>>>>> 
> >>>>>> I read the manual and looked at the code, which supports your statement. (I think I had some statement on stack overflow and the last time I believe anything on the internet :-) I have not seen a lot of differences in compile times with -j on my system. Mostly I suspect it is the number of paths in the dependency, cores and memory on the system.
> >>>>>> 
> >>>>>> I have 72 lcores or 2 sockets, 18 cores per socket. Xeon 2.3Ghz cores.
> >>>>>> 
> >>>>>> $ export RTE_TARGET=x86_64-native-linuxapp-gcc 
> >>>>>> 
> >>>>>> $ time make install T=${RTE_TARGET}
> >>>>>> real    0m59.445s user    0m27.344s sys    0m7.040s
> >>>>>> 
> >>>>>> $ time make install T=${RTE_TARGET} -j
> >>>>>> real    0m26.584s user    0m14.380s sys    0m5.120s
> >>>>>> 
> >>>>>> # Remove the x86_64-native-linuxapp-gcc
> >>>>>> 
> >>>>>> $ time make install T=${RTE_TARGET} -j 72
> >>>>>> real    0m23.454s user    0m10.832s sys    0m4.664s
> >>>>>> 
> >>>>>> $ time make install T=${RTE_TARGET} -j 8
> >>>>>> real    0m23.812s user    0m10.672s sys    0m4.276s
> >>>>>> 
> >>>>>> cd x86_64-native-linuxapp-gcc
> >>>>>> $ make clean
> >>>>>> $ time make
> >>>>>> real    0m28.539s user    0m9.820s sys    0m3.620s
> >>>>>> 
> >>>>>> # Do a make clean between each build.
> >>>>>> 
> >>>>>> $ time make -j
> >>>>>> real    0m7.217s user    0m6.532s sys    0m2.332s
> >>>>>> 
> >>>>>> $ time make -j 8
> >>>>>> real    0m8.256s user    0m6.472s sys    0m2.456s
> >>>>>> 
> >>>>>> $ time make -j 72
> >>>>>> real    0m6.866s user    0m6.184s sys    0m2.216s
> >>>>>> 
> >>>>>> Just the real time numbers in the following table.
> >>>>>> 
> >>>>>> processes     real Time   depdirs
> >>>>>>   no -j             59.4s        Yes
> >>>>>>     -j 8             23.8s        Yes
> >>>>>>    -j 72            23.5s        Yes
> >>>>>>      -j               26.5s        Yes
> >>>>>> 
> >>>>>>   no -j             28.5s         No
> >>>>>>     -j 8               8.2s         No
> >>>>>>    -j 72              6.8s         No
> >>>>>>      -j                 7.2s         No
> >>>>>> 
> >>>>>> Looks like the depdirs build time on my system:
> >>>>>> $ make clean -j
> >>>>>> $ rm .depdirs
> >>>>>> $ time make -j
> >>>>>> real    0m23.734s user    0m11.228s sys    0m4.844s
> >>>>>> 
> >>>>>> About 16 seconds, which is not a lot of savings. Now the difference from no -j to -j is a lot, but the difference between -j and -j <cpu_count> is not a huge saving. This leads me back to over engineering the problem when ‘-j’ would work just as well here.
> >>>>>> 
> >>>>>> Even on my MacBook Pro i7 system the difference is not that much 1m8s without depdirs build for -j in a VirtualBox with all 4 cores 8G RAM. Compared to 1m13s with -j 4 option.
> >>>>>> 
> >>>>>> I just wonder if it makes a lot of sense to use cpuinfo in this given case if it turns out to be -j works with the 80% rule?
> >>>>> It may, but that seems to be reason to me to just set DPDK_MAKE_JOBS=0, and
> >>>>> you'll get that behavior
> >>>> 
> >>>> Just to be sure, ‘make -j 0’ is not a valid argument to the -j option. It looks like you have to do ‘-j’ or ‘-j N’ or no option where N != 0
> >>>> 
> >>>> I think we just use -j which gets us the 80% rule and the best performance without counting cores.
> >>> Thats odd, specifying 0 works for me.  If it doesn't for you, specify $MAX_INT
> >>> or some other huge number would be comparable
> >> 
> >> rkwiles@supermicro (master):~/.../dpdk/x86_64-native-linuxapp-gcc$ make --version
> >> GNU Make 4.1
> >> Built for x86_64-pc-linux-gnu
> >> Copyright (C) 1988-2014 Free Software Foundation, Inc.
> >> License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
> >> This is free software: you are free to change and redistribute it.
> >> There is NO WARRANTY, to the extent permitted by law.
> >> 
> >> rkwiles@supermicro (master):~/.../dpdk/x86_64-native-linuxapp-gcc$ make -j 0
> >> make: the '-j' option requires a positive integer argument
> >> 
> >> rkwiles@supermicro (master):~/.../dpdk/x86_64-native-linuxapp-gcc$ lsb_release -a
> >> No LSB modules are available.
> >> Distributor ID:    Ubuntu
> >> Description:    Ubuntu 16.04.1 LTS
> >> Release:    16.04
> >> Codename:    xenial
> > I'm not saying your variant doesn't work, only that my copy of make does, but
> > its possible that I have some alternately patched version (I used to fix make
> > bugs way back when, so I may have an impure copy).  Regardless, my comment is
> > still valid, if you want to have unlimited jobs, you can just export
> > DPDK_MAKE_JOBS=<some very large number>
> 
> Neil
> 
Sorry for the delayed response, I've been on vacation.

> Your modified copy of make has no bearing on the topic we are taking about customers using dpdk in standard distros right?
> 
!?  I really don't know what you're saying here.  My only reason for commenting
on my copy of make was to consider an explination for why make -j 0 might be
working for me, and not for you.  I've since uninstalled and resinalled make on
my system, and my copy now behaves as yours does

But thats all really irrelevant.  I don't know what you mean by this not having
any bearing on the conversation since we're talking about customers using dpdk
in a distro.  We're not really talking about that at all (if we were using make
would be a moot point, since distro users tend to only use pre-compiled
binaries).  Were talking about accelerating the build process when comparing
ABIs on two different dpdk versions, thats all.

> Seems odd to me to send this out with 0 or lspci as it may fail because of no lspci and will fail on all Ubuntu systems. 
> 
Again, don't really understand what your saying.  If you look at the patch,
neither of your assertions are true.  With this patch and no other change, the
validate_abi script behaves exactly as it does now.  The only thing I've done is
add a check for the DPDK_MAKE_JOBS environment variable, and if its not set,
either:

a) Set DPDK_MAKE_JOBS to 1 if lscpu doesn't exist on the system
b) Set DPDK_MAKE_JOBS to the number of online cpus if lscpu does exist

All of that gets overridden if you manually set DPDK_MAKE_JOBS to something
else.

seems pretty straightforward to me.

> If we ship with 1 then why even bother the adding code and if I have to edit the file or some other method to get better compile performance then why bother as well.
> 
Please stop and think for a minute.  Why would you need to edit a file to change
anything?  If lscpu exists, then everything happens automatically.  If it
doesn't you can still just run:
export DPDK_MAKE_JOBS=$BIGNUMBER; validate_abi.sh <args>

and it works fine.  If ubuntu has some other utiilty besides lscpu to parse cpu
counts, fine, we can add that in as a feature, but I don't see why that should
stop other, non-ubuntu systems from taking advantage of this.

> Setting the value to some large number does not make any sense to me and if I have to edit file every time or maintain a patch just seems silly. 
> 
Goodness Keith, stop for just a minute with the editing the file train your on.
Its an environment variable, you don't have to edit a file to change it.

> It just seems easier to set it to -j and not use lspci at all. This way we all win as I am not following your logic at all.
> 
This doesn't even make any sense.  If you set it to -j then you get make issuing
jobs at the max rate make can issue them, which is potentially fine, but may not
be what developers want in the event they don't want this script to monopolize
their system.  The way its written now lets people get reasonable behavior in
most cases, and opt-in to the extreeme case should they desire.  That makes far
more sense to me, then just chewing up as much cpu as possible all the time.

Neil

> Keith
> > 
> > Neil
> > 
> >>> 
> >>> Neil
> >>> 
> >>>>> 
> >>>>> Neil
> >>>>> 
> >>>>>> On some other project with a lot more files like the FreeBSD or Linux distro, yes it would make a fair amount of real time difference.
> >>>>>> 
> >>>>>> Keith
> >>>>>> 
> >>>>>>> 
> >>>>>>> While its fine in los of cases, its not always fine, and with this
> >>>>>>> implementation you can still opt in to that behavior by setting DPDK_MAKE_JOBS=0
> >>>>>>> 
> >>>>>>> Neil
> >> 
>
  

>> Neil

>> 

> Sorry for the delayed response, I've been on vacation.

> 

>> Your modified copy of make has no bearing on the topic we are taking about customers using dpdk in standard distros right?

>> 

> !?  I really don't know what you're saying here.  My only reason for commenting

> on my copy of make was to consider an explination for why make -j 0 might be

> working for me, and not for you.  I've since uninstalled and resinalled make on

> my system, and my copy now behaves as yours does

> 

> But thats all really irrelevant.  I don't know what you mean by this not having

> any bearing on the conversation since we're talking about customers using dpdk

> in a distro.  We're not really talking about that at all (if we were using make

> would be a moot point, since distro users tend to only use pre-compiled

> binaries).  Were talking about accelerating the build process when comparing

> ABIs on two different dpdk versions, thats all.


Neil, (I am trying to not read your style of text as condescending and I will try to not do that as well)

Not everyone uses DPDK from prebuilt libraries and we need to support them as well, correct?

> 

>> Seems odd to me to send this out with 0 or lspci as it may fail because of no lspci and will fail on all Ubuntu systems. 

>> 

> Again, don't really understand what your saying.  If you look at the patch,

> neither of your assertions are true.  With this patch and no other change, the

> validate_abi script behaves exactly as it does now.  The only thing I've done is

> add a check for the DPDK_MAKE_JOBS environment variable, and if its not set,

> either:

> 

> a) Set DPDK_MAKE_JOBS to 1 if lscpu doesn't exist on the system

> b) Set DPDK_MAKE_JOBS to the number of online cpus if lscpu does exist

> 

> All of that gets overridden if you manually set DPDK_MAKE_JOBS to something

> else.

> 

> seems pretty straightforward to me.


At this point do we need to add yet another environment variable to get the correct behavior with DPDK. DPDK is very simple to build today and I worry we keep adding special variables to build DPDK. Can we just use a cleaner default, then adding more and more special build requirements? Adding this one is fine, but it also means the customer must read the docs to find this new variable.

DPDK should be build able with the least amount of docs to read, then they can read the docs more later. Just looking at how the developer can get started building DPDK without RTFM problem. At some point they need to read the docs to possibly runs the examples, but to build DPDK should very simple IMO.

> 

>> If we ship with 1 then why even bother the adding code and if I have to edit the file or some other method to get better compile performance then why bother as well.

>> 

> Please stop and think for a minute.  Why would you need to edit a file to change

> anything?  If lscpu exists, then everything happens automatically.  If it

> doesn't you can still just run:

> export DPDK_MAKE_JOBS=$BIGNUMBER; validate_abi.sh <args>


Please do not add extra environment variable we would start to get to the point of having so many pre-build requirements it becomes the private knowledge to just build DPDK or a huge setup/RTFM problem.

> 

> and it works fine.  If ubuntu has some other utiilty besides lscpu to parse cpu

> counts, fine, we can add that in as a feature, but I don't see why that should

> stop other, non-ubuntu systems from taking advantage of this.

> 

>> Setting the value to some large number does not make any sense to me and if I have to edit file every time or maintain a patch just seems silly. 

>> 

> Goodness Keith, stop for just a minute with the editing the file train your on.

> Its an environment variable, you don't have to edit a file to change it.


Yes Neil, you also need to stop an think about what you are placing on the developer to build DPDK. This one little problem is not the real issue to me, but a symptom of a growing problem in DPDK around how DPDK is build and the amount of knowledge or setup it requires to do this one simple task.

> 

>> It just seems easier to set it to -j and not use lspci at all. This way we all win as I am not following your logic at all.

>> 

> This doesn't even make any sense.  If you set it to -j then you get make issuing

> jobs at the max rate make can issue them, which is potentially fine, but may not

> be what developers want in the event they don't want this script to monopolize

> their system.  The way its written now lets people get reasonable behavior in

> most cases, and opt-in to the extreeme case should they desire.  That makes far

> more sense to me, then just chewing up as much cpu as possible all the time.


I only suggest -j as this would give the developer the best build performance without having to require lscpu or setting up yet another build environment variable. The lscpu command does not exist on all systems today and other non-Linux based systems in the future.

The amount of gain with -j over with -j is a reasonable performance option, as for chewing up cpu performance for 20-50 seconds is not a problem IMO. Please look at the bigger picture and not just your way of building DPDK as most will have a standalone machine as a development platform (I would assume) and utilizing that machine to the fullest is not a problem (unless you need to get the last digit of PI in another process :-).

I have DPDK building on Mac OS and lscpu does not exist for that system (I do not know about windows). Think about the future some and using -j just seems to have the least amount of requirements on the system, right?

If the developer does not like the ‘chew up all of my CPUs' problem then he can read the docs to set the environment variable, but I suspect that would not even happen in 99% of the cases.

Keith
  

On Mon, Aug 01, 2016 at 04:16:12PM +0000, Wiles, Keith wrote:
> 
> >> Neil
> >> 
> > Sorry for the delayed response, I've been on vacation.
> > 
> >> Your modified copy of make has no bearing on the topic we are taking about customers using dpdk in standard distros right?
> >> 
> > !?  I really don't know what you're saying here.  My only reason for commenting
> > on my copy of make was to consider an explination for why make -j 0 might be
> > working for me, and not for you.  I've since uninstalled and resinalled make on
> > my system, and my copy now behaves as yours does
> > 
> > But thats all really irrelevant.  I don't know what you mean by this not having
> > any bearing on the conversation since we're talking about customers using dpdk
> > in a distro.  We're not really talking about that at all (if we were using make
> > would be a moot point, since distro users tend to only use pre-compiled
> > binaries).  Were talking about accelerating the build process when comparing
> > ABIs on two different dpdk versions, thats all.
> 
> Neil, (I am trying to not read your style of text as condescending and I will try to not do that as well)
> 
> Not everyone uses DPDK from prebuilt libraries and we need to support them as well, correct?
> 
Correct, which is why I didn't understand your initial comment:
"Your modified copy of make has no bearing on the topic we are taking about
customers using dpdk in standard distros right?"

I read that as you saying that the topic we are discussing here is DPDK use in
standard distros, to which I am replying "No, that is not what we are talking
about here at all"

Standard Distros, as I am involved with them, are standard because the end user
typically strives to never build software included in the distro themselves.  As
such, this patch has no bearing whatsoever on those end users, because they
expect to just use a pre-built binary that conforms to a given ABI level.  They
have no need for this code

As you note, of course other upstream developers don't use pre-built binaries,
and that is who this change is targeting

> > 
> >> Seems odd to me to send this out with 0 or lspci as it may fail because of no lspci and will fail on all Ubuntu systems. 
> >> 
> > Again, don't really understand what your saying.  If you look at the patch,
> > neither of your assertions are true.  With this patch and no other change, the
> > validate_abi script behaves exactly as it does now.  The only thing I've done is
> > add a check for the DPDK_MAKE_JOBS environment variable, and if its not set,
> > either:
> > 
> > a) Set DPDK_MAKE_JOBS to 1 if lscpu doesn't exist on the system
> > b) Set DPDK_MAKE_JOBS to the number of online cpus if lscpu does exist
> > 
> > All of that gets overridden if you manually set DPDK_MAKE_JOBS to something
> > else.
> > 
> > seems pretty straightforward to me.
> 
> At this point do we need to add yet another environment variable to get the correct behavior with DPDK. DPDK is very simple to build today and I worry we keep adding special variables to build DPDK. Can we just use a cleaner default, then adding more and more special build requirements? Adding this one is fine, but it also means the customer must read the docs to find this new variable.
> 
Please read back through the thread.  The DPDK_MAKE_JOBS environment variable
was specifically used because it already exists in the build (see
test-build.sh).  Thomas specifically asked me to change the environment variable
name so that it can be resued.  We're not adding anything here that isn't
already there in other locations.

> DPDK should be build able with the least amount of docs to read, then they can read the docs more later. Just looking at how the developer can get started building DPDK without RTFM problem. At some point they need to read the docs to possibly runs the examples, but to build DPDK should very simple IMO.
So, this script has nothing to do with actually building the DPDK, only
analyzing differences in ABI between two arbitrary levels.  Nothing about this
change makes building the DPDK harder, easier, or in any way different.

> 
> > 
> >> If we ship with 1 then why even bother the adding code and if I have to edit the file or some other method to get better compile performance then why bother as well.
> >> 
> > Please stop and think for a minute.  Why would you need to edit a file to change
> > anything?  If lscpu exists, then everything happens automatically.  If it
> > doesn't you can still just run:
> > export DPDK_MAKE_JOBS=$BIGNUMBER; validate_abi.sh <args>
> 
> Please do not add extra environment variable we would start to get to the point of having so many pre-build requirements it becomes the private knowledge to just build DPDK or a huge setup/RTFM problem.
> 
See above, I'm getting the impression that you're just arguing without actually
looking at the code first.

> > 
> > and it works fine.  If ubuntu has some other utiilty besides lscpu to parse cpu
> > counts, fine, we can add that in as a feature, but I don't see why that should
> > stop other, non-ubuntu systems from taking advantage of this.
> > 
> >> Setting the value to some large number does not make any sense to me and if I have to edit file every time or maintain a patch just seems silly. 
Its no different than setting -j without an argument.  -j with no argument,
allows make to just fork jobs as deeply as the dependency graph allows (above
and beyond the number of cpus that can run them).  This can lead to large run
queues on the scheduler (depending on the amount of parallelism the dependency
graph evaluates to).  While thats not necessecarily a bad thing, it may not be
what a developer wants (as it shows up as a large load value).  Regardless,
setting -j to any number larger than the maximum number of independent jobs that
a given make file can find is equivalent to setting -j with no argument.  Thats
all I'm getting at here, export DPDK_MAKE_JOBS=<large number> is exactly
equivalent to -j without an argument for <large number> >= <max number of
parallel jobs possible>.  So you can get the behavior you want, or something
more restrictive with my patch.  If we just set -j in the validate abi script
without an argument, then we only get one of those possibilities.

If your argument is that no one would want to set anything other than maximal
job count, I would respond by saying that I like to do that frequently, because
it lets me limit the load of a build that I run, and it lets me serialize make
in the event that I want to debug a build problem.  Allowing reduced job counts
is a valuable and relevant feature.

> >> 
> > Goodness Keith, stop for just a minute with the editing the file train your on.
> > Its an environment variable, you don't have to edit a file to change it.
> 
> Yes Neil, you also need to stop an think about what you are placing on the developer to build DPDK. This one little problem is not the real issue to me, but a symptom of a growing problem in DPDK around how DPDK is build and the amount of knowledge or setup it requires to do this one simple task.
> 
Keith, I feel like you may be missing the point of this script.  This is the 3rd
time you've asserted that this change makes DPDK harder to build.  I assert 
that:

a) The validate_abi script is in no way required to build the DPDK (i.e. it is
an ancilliary tool that compares ABI at two different arbitrary points in the
project git history.  It simply does so by building the DPDK as part of its
work) 

b) The environment variable in question is already being used by other scripts
(i.e. there is nothing new being added here in terms of environment variables,
only reuse of existing ones)

c) Completely ignoring this environment variable in no way impacts behavior
(i.e. failure to set this environment variable attempts to accelerate build
parallelism within the confines of this script, if the right tools are
available, and leaves the behavior unchanged otherwise)

Can you please elaborate on how you feel this change makes DPDK harder to build?

> > 
> >> It just seems easier to set it to -j and not use lspci at all. This way we all win as I am not following your logic at all.
> >> 
> > This doesn't even make any sense.  If you set it to -j then you get make issuing
> > jobs at the max rate make can issue them, which is potentially fine, but may not
> > be what developers want in the event they don't want this script to monopolize
> > their system.  The way its written now lets people get reasonable behavior in
> > most cases, and opt-in to the extreeme case should they desire.  That makes far
> > more sense to me, then just chewing up as much cpu as possible all the time.
> 
> I only suggest -j as this would give the developer the best build performance without having to require lscpu or setting up yet another build environment variable. The lscpu command does not exist on all systems today and other non-Linux based systems in the future.
> 
In your environment it does yes, but that may not be the only thing people want,
thats what I'm saying, and I think thats worth taking into account.

Also, fwiw, lscpu should be part of every standard linux distribution, as its
part of the utils-linux package, which contains a number of core utilities to
make user space usable:
http://packages.ubuntu.com/precise/amd64/util-linux/filelist

I'm not sure if you are asserting that it doesn't exist on your ubuntu system,
but that seems to suggest that you've somehow removed it.

> The amount of gain with -j over with -j is a reasonable performance option, as for chewing up cpu performance for 20-50 seconds is not a problem IMO. Please look at the bigger picture and not just your way of building DPDK as most will have a standalone machine as a development platform (I would assume) and utilizing that machine to the fullest is not a problem (unless you need to get the last digit of PI in another process :-).
> 
Again, this utility builds the dpdk as part of its work, but is not used for the
DPDK build process itself.  That seems to be a critical difference in my mind
here.

> I have DPDK building on Mac OS and lscpu does not exist for that system (I do not know about windows). Think about the future some and using -j just seems to have the least amount of requirements on the system, right?
> 
I'm sorry, no.  From what I can see we currently support linux and bsd on a
variety of hardware architectures.  Thats what we're targeting.  I don't think
its reasonable to say no to a change because it uses a tool that may not exist
on a future operating system, that no one is targeting at the moment, or plans
to (Note also, that this script will work just fine on those systems, it will
just use the basic behavior of -j 1 because the if [ -e /usr/bin/lscpu ] test
will fail, which is more than I can say for the cpu_layout.py script, which will
traceback when reading /proc/cpuinfo or dpdk_nic_bind, which will simply fail
when trying to bind or unbind a nic using vfio on those systems)

I think thats really where were falling apart here.  You seem to be under the
impression that this script is somehow tied to the build process, and by making
this change I am somehow negatively impacting that process (or potentially
breaking it).  Thats simply not true.  This script is self contained, and is in
no way part of the build system.  The script itself just happens to build the
dpdk as part of its work internally), but a developer never has to use it to
acutally build the dpdk itself.

> If the developer does not like the ‘chew up all of my CPUs' problem then he can read the docs to set the environment variable, but I suspect that would not even happen in 99% of the cases.
Ah, so we agree in priciple, and we're just haggling over price? :)

I would counter your argument with the fact that 99% of developers also have a
system which contains lscpu, and so they will get the right amount of
parallelism for their system, not a flood of parallel jobs, nor a serialized
single job environment.  Its the happy medium I'm after, not too much, not too
little.

Neil

> 
> Keith
>