[v3,2/4] bbdev: use C11 atomic builtins for device processing counter

Message ID 1600925968-18278-3-git-send-email-phil.yang@arm.com (mailing list archive)
State Accepted, archived
Delegated to: David Marchand
Headers
Series use C11 atomic builtins for libs |

Checks

Context Check Description
ci/checkpatch success coding style OK

Commit Message

Phil Yang Sept. 24, 2020, 5:39 a.m. UTC
  Since rte_atomicXX APIs are not allowed to be used, use C11 atomic builtins
for device processing counter.

Signed-off-by: Phil Yang <phil.yang@arm.com>
Reviewed-by: Ruifeng Wang <ruifeng.wang@arm.com>
Reviewed-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
---
 lib/librte_bbdev/rte_bbdev.c | 5 +++--
 lib/librte_bbdev/rte_bbdev.h | 4 +---
 2 files changed, 4 insertions(+), 5 deletions(-)
  

Comments

Chautru, Nicolas Sept. 24, 2020, 10:01 p.m. UTC | #1
Hi Phil, 
Naïve question but the deprecation document was stating that "DPDK will adopt C11 atomic operations semantics and provide wrappers using C11 atomic built-ins."
Here you are using directly the C11 atomic built-ins and not providing and using a DPDK wrapper. 
Wasn't the intent to have a new rte_... wrapper here? Ie. the same way as the __sync_fetch_and_add() were called before behind the rte_atomicNN_XX wrapper. 

Thanks
Nic


> -----Original Message-----
> From: Phil Yang <phil.yang@arm.com>
> Sent: Wednesday, September 23, 2020 10:39 PM
> To: dev@dpdk.org; david.marchand@redhat.com; Chautru, Nicolas
> <nicolas.chautru@intel.com>; Hunt, David <david.hunt@intel.com>
> Cc: Ruifeng.Wang@arm.com; Honnappa.Nagarahalli@arm.com;
> nd@arm.com
> Subject: [PATCH v3 2/4] bbdev: use C11 atomic builtins for device processing
> counter
> 
> Since rte_atomicXX APIs are not allowed to be used, use C11 atomic builtins
> for device processing counter.
> 
> Signed-off-by: Phil Yang <phil.yang@arm.com>
> Reviewed-by: Ruifeng Wang <ruifeng.wang@arm.com>
> Reviewed-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
> ---
>  lib/librte_bbdev/rte_bbdev.c | 5 +++--
>  lib/librte_bbdev/rte_bbdev.h | 4 +---
>  2 files changed, 4 insertions(+), 5 deletions(-)
> 
> diff --git a/lib/librte_bbdev/rte_bbdev.c b/lib/librte_bbdev/rte_bbdev.c
> index a4fdb69..5ba891c 100644
> --- a/lib/librte_bbdev/rte_bbdev.c
> +++ b/lib/librte_bbdev/rte_bbdev.c
> @@ -210,7 +210,7 @@ rte_bbdev_allocate(const char *name)
>  		return NULL;
>  	}
> 
> -	rte_atomic16_inc(&bbdev->data->process_cnt);
> +	__atomic_add_fetch(&bbdev->data->process_cnt, 1,
> __ATOMIC_RELAXED);
>  	bbdev->data->dev_id = dev_id;
>  	bbdev->state = RTE_BBDEV_INITIALIZED;
> 
> @@ -252,7 +252,8 @@ rte_bbdev_release(struct rte_bbdev *bbdev)
>  	}
> 
>  	/* clear shared BBDev Data if no process is using the device anymore
> */
> -	if (rte_atomic16_dec_and_test(&bbdev->data->process_cnt))
> +	if (__atomic_sub_fetch(&bbdev->data->process_cnt, 1,
> +			      __ATOMIC_RELAXED) == 0)
>  		memset(bbdev->data, 0, sizeof(*bbdev->data));
> 
>  	memset(bbdev, 0, sizeof(*bbdev));
> diff --git a/lib/librte_bbdev/rte_bbdev.h b/lib/librte_bbdev/rte_bbdev.h
> index 5729137..7017124 100644
> --- a/lib/librte_bbdev/rte_bbdev.h
> +++ b/lib/librte_bbdev/rte_bbdev.h
> @@ -33,7 +33,6 @@ extern "C" {
>  #include <string.h>
> 
>  #include <rte_compat.h>
> -#include <rte_atomic.h>
>  #include <rte_bus.h>
>  #include <rte_cpuflags.h>
>  #include <rte_memory.h>
> @@ -426,8 +425,7 @@ struct rte_bbdev_data {
>  	uint16_t dev_id;  /**< Device ID */
>  	int socket_id;  /**< NUMA socket that device is on */
>  	bool started;  /**< Device run-time state */
> -	/** Counter of processes using the device */
> -	rte_atomic16_t process_cnt;
> +	uint16_t process_cnt;  /** Counter of processes using the device */
>  };
> 
>  /* Forward declarations */
> --
> 2.7.4
  
Honnappa Nagarahalli Sept. 24, 2020, 10:44 p.m. UTC | #2
<snip>

> 
> Hi Phil,
> Naïve question but the deprecation document was stating that "DPDK will
> adopt C11 atomic operations semantics and provide wrappers using C11
> atomic built-ins."
At the time of writing the deprecation notice, that was the thinking. However, through further discussions [1] in the community, it was decided to use atomic built-ins.

[1] http://mails.dpdk.org/archives/dev/2020-May/167416.html

> Here you are using directly the C11 atomic built-ins and not providing and
> using a DPDK wrapper.
> Wasn't the intent to have a new rte_... wrapper here? Ie. the same way as
> the __sync_fetch_and_add() were called before behind the rte_atomicNN_XX
> wrapper.
> 
> Thanks
> Nic
> 
> 
> > -----Original Message-----
> > From: Phil Yang <phil.yang@arm.com>
> > Sent: Wednesday, September 23, 2020 10:39 PM
> > To: dev@dpdk.org; david.marchand@redhat.com; Chautru, Nicolas
> > <nicolas.chautru@intel.com>; Hunt, David <david.hunt@intel.com>
> > Cc: Ruifeng.Wang@arm.com; Honnappa.Nagarahalli@arm.com;
> nd@arm.com
> > Subject: [PATCH v3 2/4] bbdev: use C11 atomic builtins for device
> > processing counter
> >
> > Since rte_atomicXX APIs are not allowed to be used, use C11 atomic
> > builtins for device processing counter.
> >
> > Signed-off-by: Phil Yang <phil.yang@arm.com>
> > Reviewed-by: Ruifeng Wang <ruifeng.wang@arm.com>
> > Reviewed-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
> > ---
> >  lib/librte_bbdev/rte_bbdev.c | 5 +++--  lib/librte_bbdev/rte_bbdev.h
> > | 4 +---
> >  2 files changed, 4 insertions(+), 5 deletions(-)
> >
> > diff --git a/lib/librte_bbdev/rte_bbdev.c
> > b/lib/librte_bbdev/rte_bbdev.c index a4fdb69..5ba891c 100644
> > --- a/lib/librte_bbdev/rte_bbdev.c
> > +++ b/lib/librte_bbdev/rte_bbdev.c
> > @@ -210,7 +210,7 @@ rte_bbdev_allocate(const char *name)
> >  		return NULL;
> >  	}
> >
> > -	rte_atomic16_inc(&bbdev->data->process_cnt);
> > +	__atomic_add_fetch(&bbdev->data->process_cnt, 1,
> > __ATOMIC_RELAXED);
> >  	bbdev->data->dev_id = dev_id;
> >  	bbdev->state = RTE_BBDEV_INITIALIZED;
> >
> > @@ -252,7 +252,8 @@ rte_bbdev_release(struct rte_bbdev *bbdev)
> >  	}
> >
> >  	/* clear shared BBDev Data if no process is using the device anymore
> > */
> > -	if (rte_atomic16_dec_and_test(&bbdev->data->process_cnt))
> > +	if (__atomic_sub_fetch(&bbdev->data->process_cnt, 1,
> > +			      __ATOMIC_RELAXED) == 0)
> >  		memset(bbdev->data, 0, sizeof(*bbdev->data));
> >
> >  	memset(bbdev, 0, sizeof(*bbdev));
> > diff --git a/lib/librte_bbdev/rte_bbdev.h
> > b/lib/librte_bbdev/rte_bbdev.h index 5729137..7017124 100644
> > --- a/lib/librte_bbdev/rte_bbdev.h
> > +++ b/lib/librte_bbdev/rte_bbdev.h
> > @@ -33,7 +33,6 @@ extern "C" {
> >  #include <string.h>
> >
> >  #include <rte_compat.h>
> > -#include <rte_atomic.h>
> >  #include <rte_bus.h>
> >  #include <rte_cpuflags.h>
> >  #include <rte_memory.h>
> > @@ -426,8 +425,7 @@ struct rte_bbdev_data {
> >  	uint16_t dev_id;  /**< Device ID */
> >  	int socket_id;  /**< NUMA socket that device is on */
> >  	bool started;  /**< Device run-time state */
> > -	/** Counter of processes using the device */
> > -	rte_atomic16_t process_cnt;
> > +	uint16_t process_cnt;  /** Counter of processes using the device */
> >  };
> >
> >  /* Forward declarations */
> > --
> > 2.7.4
  
Chautru, Nicolas Sept. 24, 2020, 11:20 p.m. UTC | #3
Thanks Honnappa, 

Acked-By: Nicolas Chautru <nicolas.chautru@intel.com>

> -----Original Message-----
> From: Honnappa Nagarahalli <Honnappa.Nagarahalli@arm.com>
> Sent: Thursday, September 24, 2020 3:45 PM
> To: Chautru, Nicolas <nicolas.chautru@intel.com>; Phil Yang
> <Phil.Yang@arm.com>; dev@dpdk.org; david.marchand@redhat.com; Hunt,
> David <david.hunt@intel.com>
> Cc: Ruifeng Wang <Ruifeng.Wang@arm.com>; nd <nd@arm.com>;
> Honnappa Nagarahalli <Honnappa.Nagarahalli@arm.com>; nd
> <nd@arm.com>
> Subject: RE: [PATCH v3 2/4] bbdev: use C11 atomic builtins for device
> processing counter
> 
> <snip>
> 
> >
> > Hi Phil,
> > Naïve question but the deprecation document was stating that "DPDK
> > will adopt C11 atomic operations semantics and provide wrappers using
> > C11 atomic built-ins."
> At the time of writing the deprecation notice, that was the thinking.
> However, through further discussions [1] in the community, it was decided
> to use atomic built-ins.
> 
> [1] http://mails.dpdk.org/archives/dev/2020-May/167416.html
> 
> > Here you are using directly the C11 atomic built-ins and not providing
> > and using a DPDK wrapper.
> > Wasn't the intent to have a new rte_... wrapper here? Ie. the same way
> > as the __sync_fetch_and_add() were called before behind the
> > rte_atomicNN_XX wrapper.
> >
> > Thanks
> > Nic
> >
> >
> > > -----Original Message-----
> > > From: Phil Yang <phil.yang@arm.com>
> > > Sent: Wednesday, September 23, 2020 10:39 PM
> > > To: dev@dpdk.org; david.marchand@redhat.com; Chautru, Nicolas
> > > <nicolas.chautru@intel.com>; Hunt, David <david.hunt@intel.com>
> > > Cc: Ruifeng.Wang@arm.com; Honnappa.Nagarahalli@arm.com;
> > nd@arm.com
> > > Subject: [PATCH v3 2/4] bbdev: use C11 atomic builtins for device
> > > processing counter
> > >
> > > Since rte_atomicXX APIs are not allowed to be used, use C11 atomic
> > > builtins for device processing counter.
> > >
> > > Signed-off-by: Phil Yang <phil.yang@arm.com>
> > > Reviewed-by: Ruifeng Wang <ruifeng.wang@arm.com>
> > > Reviewed-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
> > > ---
> > >  lib/librte_bbdev/rte_bbdev.c | 5 +++--
> > > lib/librte_bbdev/rte_bbdev.h
> > > | 4 +---
> > >  2 files changed, 4 insertions(+), 5 deletions(-)
> > >
> > > diff --git a/lib/librte_bbdev/rte_bbdev.c
> > > b/lib/librte_bbdev/rte_bbdev.c index a4fdb69..5ba891c 100644
> > > --- a/lib/librte_bbdev/rte_bbdev.c
> > > +++ b/lib/librte_bbdev/rte_bbdev.c
> > > @@ -210,7 +210,7 @@ rte_bbdev_allocate(const char *name)
> > >  		return NULL;
> > >  	}
> > >
> > > -	rte_atomic16_inc(&bbdev->data->process_cnt);
> > > +	__atomic_add_fetch(&bbdev->data->process_cnt, 1,
> > > __ATOMIC_RELAXED);
> > >  	bbdev->data->dev_id = dev_id;
> > >  	bbdev->state = RTE_BBDEV_INITIALIZED;
> > >
> > > @@ -252,7 +252,8 @@ rte_bbdev_release(struct rte_bbdev *bbdev)
> > >  	}
> > >
> > >  	/* clear shared BBDev Data if no process is using the device
> > > anymore */
> > > -	if (rte_atomic16_dec_and_test(&bbdev->data->process_cnt))
> > > +	if (__atomic_sub_fetch(&bbdev->data->process_cnt, 1,
> > > +			      __ATOMIC_RELAXED) == 0)
> > >  		memset(bbdev->data, 0, sizeof(*bbdev->data));
> > >
> > >  	memset(bbdev, 0, sizeof(*bbdev));
> > > diff --git a/lib/librte_bbdev/rte_bbdev.h
> > > b/lib/librte_bbdev/rte_bbdev.h index 5729137..7017124 100644
> > > --- a/lib/librte_bbdev/rte_bbdev.h
> > > +++ b/lib/librte_bbdev/rte_bbdev.h
> > > @@ -33,7 +33,6 @@ extern "C" {
> > >  #include <string.h>
> > >
> > >  #include <rte_compat.h>
> > > -#include <rte_atomic.h>
> > >  #include <rte_bus.h>
> > >  #include <rte_cpuflags.h>
> > >  #include <rte_memory.h>
> > > @@ -426,8 +425,7 @@ struct rte_bbdev_data {
> > >  	uint16_t dev_id;  /**< Device ID */
> > >  	int socket_id;  /**< NUMA socket that device is on */
> > >  	bool started;  /**< Device run-time state */
> > > -	/** Counter of processes using the device */
> > > -	rte_atomic16_t process_cnt;
> > > +	uint16_t process_cnt;  /** Counter of processes using the device
> > > +*/
> > >  };
> > >
> > >  /* Forward declarations */
> > > --
> > > 2.7.4
  

Patch

diff --git a/lib/librte_bbdev/rte_bbdev.c b/lib/librte_bbdev/rte_bbdev.c
index a4fdb69..5ba891c 100644
--- a/lib/librte_bbdev/rte_bbdev.c
+++ b/lib/librte_bbdev/rte_bbdev.c
@@ -210,7 +210,7 @@  rte_bbdev_allocate(const char *name)
 		return NULL;
 	}
 
-	rte_atomic16_inc(&bbdev->data->process_cnt);
+	__atomic_add_fetch(&bbdev->data->process_cnt, 1, __ATOMIC_RELAXED);
 	bbdev->data->dev_id = dev_id;
 	bbdev->state = RTE_BBDEV_INITIALIZED;
 
@@ -252,7 +252,8 @@  rte_bbdev_release(struct rte_bbdev *bbdev)
 	}
 
 	/* clear shared BBDev Data if no process is using the device anymore */
-	if (rte_atomic16_dec_and_test(&bbdev->data->process_cnt))
+	if (__atomic_sub_fetch(&bbdev->data->process_cnt, 1,
+			      __ATOMIC_RELAXED) == 0)
 		memset(bbdev->data, 0, sizeof(*bbdev->data));
 
 	memset(bbdev, 0, sizeof(*bbdev));
diff --git a/lib/librte_bbdev/rte_bbdev.h b/lib/librte_bbdev/rte_bbdev.h
index 5729137..7017124 100644
--- a/lib/librte_bbdev/rte_bbdev.h
+++ b/lib/librte_bbdev/rte_bbdev.h
@@ -33,7 +33,6 @@  extern "C" {
 #include <string.h>
 
 #include <rte_compat.h>
-#include <rte_atomic.h>
 #include <rte_bus.h>
 #include <rte_cpuflags.h>
 #include <rte_memory.h>
@@ -426,8 +425,7 @@  struct rte_bbdev_data {
 	uint16_t dev_id;  /**< Device ID */
 	int socket_id;  /**< NUMA socket that device is on */
 	bool started;  /**< Device run-time state */
-	/** Counter of processes using the device */
-	rte_atomic16_t process_cnt;
+	uint16_t process_cnt;  /** Counter of processes using the device */
 };
 
 /* Forward declarations */