* [PATCH] perf test: Compile named_threads workload with -O0
@ 2026-06-11 11:13 James Clark
2026-06-11 12:38 ` Leo Yan
` (2 more replies)
0 siblings, 3 replies; 5+ messages in thread
From: James Clark @ 2026-06-11 11:13 UTC (permalink / raw)
To: Arnaldo Carvalho de Melo, Namhyung Kim, Ian Rogers, Leo Yan
Cc: linux-perf-users, linux-kernel, James Clark
The work loop relies on the compiler not optimizing it away, although
named_threads_work is not static for that reason, the compiler could
still do it.
Fix it by compiling without optimization. Also add -fno-inline for
consistency and in case anyone wants to look at callstacks.
Signed-off-by: James Clark <james.clark@linaro.org>
---
One trailing Sashiko fix from the "perf cs-etm: Queue context packets
for frontend" patch series that has been applied already.
---
tools/perf/tests/workloads/Build | 1 +
1 file changed, 1 insertion(+)
diff --git a/tools/perf/tests/workloads/Build b/tools/perf/tests/workloads/Build
index 75b377934a0e..7bb4b9829ba2 100644
--- a/tools/perf/tests/workloads/Build
+++ b/tools/perf/tests/workloads/Build
@@ -26,3 +26,4 @@ CFLAGS_datasym.o = -g -O0 -fno-inline -U_FORTIFY_SOURCE
CFLAGS_traploop.o = -g -O0 -fno-inline -U_FORTIFY_SOURCE
CFLAGS_inlineloop.o = -g -O2
CFLAGS_deterministic.o = -g -O0 -fno-inline -U_FORTIFY_SOURCE
+CFLAGS_named_threads.o = -g -O0 -fno-inline -U_FORTIFY_SOURCE
---
base-commit: 7336514f41e75d44782fee7e0990d4195a3d3161
change-id: 20260611-james-cs-unformatted-per-thread-fix-followup-babf28a4e640
Best regards,
--
James Clark <james.clark@linaro.org>
^ permalink raw reply related [flat|nested] 5+ messages in thread* Re: [PATCH] perf test: Compile named_threads workload with -O0
2026-06-11 11:13 [PATCH] perf test: Compile named_threads workload with -O0 James Clark
@ 2026-06-11 12:38 ` Leo Yan
2026-06-11 15:08 ` Arnaldo Carvalho de Melo
2026-06-11 18:54 ` David Laight
2 siblings, 0 replies; 5+ messages in thread
From: Leo Yan @ 2026-06-11 12:38 UTC (permalink / raw)
To: James Clark
Cc: Arnaldo Carvalho de Melo, Namhyung Kim, Ian Rogers,
linux-perf-users, linux-kernel
On Thu, Jun 11, 2026 at 12:13:46PM +0100, James Clark wrote:
> The work loop relies on the compiler not optimizing it away, although
> named_threads_work is not static for that reason, the compiler could
> still do it.
>
> Fix it by compiling without optimization. Also add -fno-inline for
> consistency and in case anyone wants to look at callstacks.
>
> Signed-off-by: James Clark <james.clark@linaro.org>
Reviewed-by: Leo Yan <leo.yan@arm.com>
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] perf test: Compile named_threads workload with -O0
2026-06-11 11:13 [PATCH] perf test: Compile named_threads workload with -O0 James Clark
2026-06-11 12:38 ` Leo Yan
@ 2026-06-11 15:08 ` Arnaldo Carvalho de Melo
2026-06-11 15:11 ` James Clark
2026-06-11 18:54 ` David Laight
2 siblings, 1 reply; 5+ messages in thread
From: Arnaldo Carvalho de Melo @ 2026-06-11 15:08 UTC (permalink / raw)
To: James Clark
Cc: Namhyung Kim, Ian Rogers, Leo Yan, linux-perf-users, linux-kernel
On Thu, Jun 11, 2026 at 12:13:46PM +0100, James Clark wrote:
> The work loop relies on the compiler not optimizing it away, although
> named_threads_work is not static for that reason, the compiler could
> still do it.
>
> Fix it by compiling without optimization. Also add -fno-inline for
> consistency and in case anyone wants to look at callstacks.
>
> Signed-off-by: James Clark <james.clark@linaro.org>
> ---
> One trailing Sashiko fix from the "perf cs-etm: Queue context packets
> for frontend" patch series that has been applied already.
I'll add a Fixes tag pointing to that cset, also a reported-by sashiko
and a closes, for completeness.
Thanks, applying.
- Arnaldo
> ---
> tools/perf/tests/workloads/Build | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/tools/perf/tests/workloads/Build b/tools/perf/tests/workloads/Build
> index 75b377934a0e..7bb4b9829ba2 100644
> --- a/tools/perf/tests/workloads/Build
> +++ b/tools/perf/tests/workloads/Build
> @@ -26,3 +26,4 @@ CFLAGS_datasym.o = -g -O0 -fno-inline -U_FORTIFY_SOURCE
> CFLAGS_traploop.o = -g -O0 -fno-inline -U_FORTIFY_SOURCE
> CFLAGS_inlineloop.o = -g -O2
> CFLAGS_deterministic.o = -g -O0 -fno-inline -U_FORTIFY_SOURCE
> +CFLAGS_named_threads.o = -g -O0 -fno-inline -U_FORTIFY_SOURCE
>
> ---
> base-commit: 7336514f41e75d44782fee7e0990d4195a3d3161
> change-id: 20260611-james-cs-unformatted-per-thread-fix-followup-babf28a4e640
>
> Best regards,
> --
> James Clark <james.clark@linaro.org>
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] perf test: Compile named_threads workload with -O0
2026-06-11 15:08 ` Arnaldo Carvalho de Melo
@ 2026-06-11 15:11 ` James Clark
0 siblings, 0 replies; 5+ messages in thread
From: James Clark @ 2026-06-11 15:11 UTC (permalink / raw)
To: Arnaldo Carvalho de Melo
Cc: Namhyung Kim, Ian Rogers, Leo Yan, linux-perf-users, linux-kernel
On 11/06/2026 4:08 pm, Arnaldo Carvalho de Melo wrote:
> On Thu, Jun 11, 2026 at 12:13:46PM +0100, James Clark wrote:
>> The work loop relies on the compiler not optimizing it away, although
>> named_threads_work is not static for that reason, the compiler could
>> still do it.
>>
>> Fix it by compiling without optimization. Also add -fno-inline for
>> consistency and in case anyone wants to look at callstacks.
>>
>> Signed-off-by: James Clark <james.clark@linaro.org>
>> ---
>> One trailing Sashiko fix from the "perf cs-etm: Queue context packets
>> for frontend" patch series that has been applied already.
>
> I'll add a Fixes tag pointing to that cset, also a reported-by sashiko
> and a closes, for completeness.
>
> Thanks, applying.
>
> - Arnaldo
>
Thanks, makes sense yeah. I probably could have been a bit more thorough.
>> ---
>> tools/perf/tests/workloads/Build | 1 +
>> 1 file changed, 1 insertion(+)
>>
>> diff --git a/tools/perf/tests/workloads/Build b/tools/perf/tests/workloads/Build
>> index 75b377934a0e..7bb4b9829ba2 100644
>> --- a/tools/perf/tests/workloads/Build
>> +++ b/tools/perf/tests/workloads/Build
>> @@ -26,3 +26,4 @@ CFLAGS_datasym.o = -g -O0 -fno-inline -U_FORTIFY_SOURCE
>> CFLAGS_traploop.o = -g -O0 -fno-inline -U_FORTIFY_SOURCE
>> CFLAGS_inlineloop.o = -g -O2
>> CFLAGS_deterministic.o = -g -O0 -fno-inline -U_FORTIFY_SOURCE
>> +CFLAGS_named_threads.o = -g -O0 -fno-inline -U_FORTIFY_SOURCE
>>
>> ---
>> base-commit: 7336514f41e75d44782fee7e0990d4195a3d3161
>> change-id: 20260611-james-cs-unformatted-per-thread-fix-followup-babf28a4e640
>>
>> Best regards,
>> --
>> James Clark <james.clark@linaro.org>
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] perf test: Compile named_threads workload with -O0
2026-06-11 11:13 [PATCH] perf test: Compile named_threads workload with -O0 James Clark
2026-06-11 12:38 ` Leo Yan
2026-06-11 15:08 ` Arnaldo Carvalho de Melo
@ 2026-06-11 18:54 ` David Laight
2 siblings, 0 replies; 5+ messages in thread
From: David Laight @ 2026-06-11 18:54 UTC (permalink / raw)
To: James Clark
Cc: Arnaldo Carvalho de Melo, Namhyung Kim, Ian Rogers, Leo Yan,
linux-perf-users, linux-kernel
On Thu, 11 Jun 2026 12:13:46 +0100
James Clark <james.clark@linaro.org> wrote:
> The work loop relies on the compiler not optimizing it away, although
> named_threads_work is not static for that reason, the compiler could
> still do it.
Isn't in enough to put barrier() in the loop?
David
>
> Fix it by compiling without optimization. Also add -fno-inline for
> consistency and in case anyone wants to look at callstacks.
>
> Signed-off-by: James Clark <james.clark@linaro.org>
> ---
> One trailing Sashiko fix from the "perf cs-etm: Queue context packets
> for frontend" patch series that has been applied already.
> ---
> tools/perf/tests/workloads/Build | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/tools/perf/tests/workloads/Build b/tools/perf/tests/workloads/Build
> index 75b377934a0e..7bb4b9829ba2 100644
> --- a/tools/perf/tests/workloads/Build
> +++ b/tools/perf/tests/workloads/Build
> @@ -26,3 +26,4 @@ CFLAGS_datasym.o = -g -O0 -fno-inline -U_FORTIFY_SOURCE
> CFLAGS_traploop.o = -g -O0 -fno-inline -U_FORTIFY_SOURCE
> CFLAGS_inlineloop.o = -g -O2
> CFLAGS_deterministic.o = -g -O0 -fno-inline -U_FORTIFY_SOURCE
> +CFLAGS_named_threads.o = -g -O0 -fno-inline -U_FORTIFY_SOURCE
>
> ---
> base-commit: 7336514f41e75d44782fee7e0990d4195a3d3161
> change-id: 20260611-james-cs-unformatted-per-thread-fix-followup-babf28a4e640
>
> Best regards,
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2026-06-11 18:54 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz follow: Atom feed
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2026-06-11 11:13 [PATCH] perf test: Compile named_threads workload with -O0 James Clark
2026-06-11 12:38 ` Leo Yan
2026-06-11 15:08 ` Arnaldo Carvalho de Melo
2026-06-11 15:11 ` James Clark
2026-06-11 18:54 ` David Laight
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