Re: [PATCH v2] kernel: release ptraced tasks before zap_pid_ns_processes
From: Jiri Slaby
Date: Wed Feb 27 2019 - 03:03:43 EST
On 26. 02. 19, 16:30, Oleg Nesterov wrote:
>> from our (SUSE) QA we received a report that this patch causes a
>> performance decline in libmicro pthread_* benchmark as reported in:
> Access Denied
>> I tried myself from the repo:
>> I ran
>> pthread_create -B 8 -C 200 -S
>> and with the patch applied:
>> # STATISTICS usecs/call (raw) usecs/call (outliers removed)
>> # mean 23.38611 17.29311
>> # mean 41.36539 39.21347
> can't reproduce, I see the same numbers with or without this patch.
> However, I did "./bin/pthread_create -B 8 -C 200 -S" under KVM.
Correct. I did the tests also under KVM. The above difference happens
when you compare (by stupid mistake) a LOCKDEP and non-LOCKDEP kernel --
sorry. So the proper results are comparably the same -- the difference
is on the noise level. So it must be their setup broken too.
Thanks for the input anyway.