Re: [PATCH v3 0/2] pipe: don't update {a,c,m}time for anonymous pipes

K Prateek Nayak
2025-02-06T03:16:11Z

Hello Oleg,

On 2/5/2025 11:47 PM, Oleg Nesterov wrote:
> OK, let me send v3 right now...

Tested this series with sched-messaging on my 3rd Generation EPYC
system (2 x64c/128T, boost on, C2 disabled) and I see slight
improvements:

==================================================================
Test : sched-messaging
Units : Normalized time in seconds
Interpretation: Lower is better
Statistic : AMean
==================================================================
Case: upstream[pct imp](CV) skip_{a,c,m}_time[pct imp](CV)
1-groups 1.00 [ -0.00]( 9.88) 1.05 [ -5.16]( 7.19) *
2-groups 1.00 [ -0.00]( 3.49) 0.97 [ 2.70]( 3.54)
4-groups 1.00 [ -0.00]( 1.22) 0.97 [ 2.70]( 2.78)
8-groups 1.00 [ -0.00]( 0.80) 0.99 [ 0.94]( 1.04)
16-groups 1.00 [ -0.00]( 1.40) 0.98 [ 2.43]( 1.02)

* Disregard these data points due to large run to run variation

Feel free to add:

Tested-by: K Prateek Nayak <kprateek.nayak@amd.com>

I'll go test the pipe_{read,write}() cleanup you had posted on the
other thread.

--
Thanks and Regards,
Prateek

>
> Changes: make pipeanon_fops static.
>
> Link to v1: https://lore.kernel.org/all/20250204132153.GA20921@redhat.com/
> Link to v2: https://lore.kernel.org/all/20250205161636.GA1001@redhat.com/
>
> Oleg.
> ---
>
> fs/pipe.c | 62 +++++++++++++++++++++++++++++++++++++++++++++++---------------
> 1 file changed, 47 insertions(+), 15 deletions(-)
>