[v9,2/3] devtools: prevent use of rte atomic APIs in future patches
Checks
Commit Message
In order to deprecate the rte_atomic and rte_smp barrier APIs, prevent
the patches from using these APIs and __sync builtins in new code.
On x86 the __atomic_thread_fence(__ATOMIC_SEQ_CST) is quite expensive
for SMP case. Flag the new code which use __atomic_thread_fence API.
Signed-off-by: Phil Yang <phil.yang@arm.com>
Reviewed-by: Ruifeng Wang <ruifeng.wang@arm.com>
---
devtools/checkpatches.sh | 35 +++++++++++++++++++++++++++++++++++
1 file changed, 35 insertions(+)
Comments
17/07/2020 07:08, Phil Yang:
> In order to deprecate the rte_atomic and rte_smp barrier APIs, prevent
> the patches from using these APIs and __sync builtins in new code.
>
> On x86 the __atomic_thread_fence(__ATOMIC_SEQ_CST) is quite expensive
> for SMP case. Flag the new code which use __atomic_thread_fence API.
When receiving such message error, I would look at the explanations
in the git history. Unfortunately this commit log does not reference
the documentation. Please add a link and give the 4 direct replacements
in this commit log.
Thomas Monjalon <thomas@monjalon.net> wrties:
> > In order to deprecate the rte_atomic and rte_smp barrier APIs, prevent
> > the patches from using these APIs and __sync builtins in new code.
> >
> > On x86 the __atomic_thread_fence(__ATOMIC_SEQ_CST) is quite
> expensive
> > for SMP case. Flag the new code which use __atomic_thread_fence API.
>
> When receiving such message error, I would look at the explanations
> in the git history. Unfortunately this commit log does not reference
> the documentation. Please add a link and give the 4 direct replacements
> in this commit log.
I will update it in v10. Thanks.
How about putting it like this? (Truncated the long link to pass the long line check)
"
In order to deprecate the rte_atomic and rte_smp barrier APIs[1], prevent
the patches from using these APIs and __sync builtins in new code. Please
use __atomic builtins instead of __sync builtins, rte_atomicNN_xxx and
rte_smp_[r/w]mb APIs.
On x86 the __atomic_thread_fence(__ATOMIC_SEQ_CST) is quite expensive for
SMP case. Flag the new code which use __atomic_thread_fence API. Please
use rte_thread_fence API instead of __atomic_thread_fence.
[1] Refer to the locks-and-atomic-operations section in
https://doc.dpdk.org/guides/prog_guide/writing_efficient_code.html.
"
@@ -77,6 +77,41 @@ check_forbidden_additions() { # <patch>
-f $(dirname $(readlink -f $0))/check-forbidden-tokens.awk \
"$1" || res=1
+ # refrain from new additions of 16/32/64 bits rte_atomic_xxx()
+ # multiple folders and expressions are separated by spaces
+ awk -v FOLDERS="lib drivers app examples" \
+ -v EXPRESSIONS="rte_atomic[0-9][0-9]_.*\\\(" \
+ -v RET_ON_FAIL=1 \
+ -v MESSAGE='Using rte_atomicNN_xxx' \
+ -f $(dirname $(readlink -f $0))/check-forbidden-tokens.awk \
+ "$1" || res=1
+
+ # refrain from new additions of rte_smp_XXmb()
+ # multiple folders and expressions are separated by spaces
+ awk -v FOLDERS="lib drivers app examples" \
+ -v EXPRESSIONS="rte_smp_(r|w)?mb\\\(" \
+ -v RET_ON_FAIL=1 \
+ -v MESSAGE='Using rte_smp_[r/w]mb' \
+ -f $(dirname $(readlink -f $0))/check-forbidden-tokens.awk \
+ "$1" || res=1
+
+ # refrain from using compiler __sync builtins
+ awk -v FOLDERS="lib drivers app examples" \
+ -v EXPRESSIONS="__sync_.*\\\(" \
+ -v RET_ON_FAIL=1 \
+ -v MESSAGE='Using __sync_xxx builtins' \
+ -f $(dirname $(readlink -f $0))/check-forbidden-tokens.awk \
+ "$1" || res=1
+
+ # refrain from using compiler __atomic_thread_fence()
+ # It should be avoided on x86 for SMP case.
+ awk -v FOLDERS="lib drivers app examples" \
+ -v EXPRESSIONS="__atomic_thread_fence\\\(" \
+ -v RET_ON_FAIL=1 \
+ -v MESSAGE='Using __atomic_thread_fence' \
+ -f $(dirname $(readlink -f $0))/check-forbidden-tokens.awk \
+ "$1" || res=1
+
# svg figures must be included with wildcard extension
# because of png conversion for pdf docs
awk -v FOLDERS='doc' \