From: Nadav Amit <namit@vmware.com>
To: kernel test robot <rong.a.chen@intel.com>
Cc: Ingo Molnar <mingo@kernel.org>,
Thomas Gleixner <tglx@linutronix.de>,
Andy Lutomirski <luto@amacapital.net>,
Rick Edgecombe <rick.p.edgecombe@intel.com>,
Peter Zijlstra <peterz@infradead.org>,
Andy Lutomirski <luto@kernel.org>, Borislav Petkov <bp@alien8.de>,
Dave Hansen <dave.hansen@intel.com>,
"H. Peter Anvin" <hpa@zytor.com>, Jessica Yu <jeyu@kernel.org>,
Kees Cook <keescook@chromium.org>,
Linus Torvalds <torvalds@linux-foundation.org>,
Masami Hiramatsu <mhiramat@kernel.org>,
Rik van Riel <riel@surriel.com>,
LKML <linux-kernel@vger.kernel.org>, "lkp@01.org" <lkp@01.org>
Subject: Re: [x86/modules] f2c65fb322: will-it-scale.per_process_ops -2.9% regression
Date: Thu, 18 Jul 2019 17:59:08 +0000 [thread overview]
Message-ID: <52D013BF-9B4B-4D03-B56F-3F378E4A2BA4@vmware.com> (raw)
In-Reply-To: <20190718095037.GC27250@shao2-debian>
> On Jul 18, 2019, at 2:50 AM, kernel test robot <rong.a.chen@intel.com> wrote:
>
> Greeting,
>
> FYI, we noticed a -2.9% regression of will-it-scale.per_process_ops due to commit:
>
>
> commit: f2c65fb3221adc6b73b0549fc7ba892022db9797 ("x86/modules: Avoid breaking W^X while loading modules")
> https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Fkernel.googlesource.com%2Fpub%2Fscm%2Flinux%2Fkernel%2Fgit%2Ftorvalds%2Flinux.git&data=02%7C01%7Cnamit%40vmware.com%7Cdfe19d72eecd46a93fc508d70b65652b%7Cb39138ca3cee4b4aa4d6cd83d9dd62f0%7C0%7C0%7C636990402460329367&sdata=9MHPlha0MIkDWKe%2BurDDr0QRDMtJ3pPACgDtVXy8pL4%3D&reserved=0 master
>
> in testcase: will-it-scale
> on test machine: 192 threads Intel(R) Xeon(R) CPU @ 2.20GHz with 192G memory
> with following parameters:
>
> nr_task: 100%
> mode: process
> test: poll1
> cpufreq_governor: performance
>
> test-description: Will It Scale takes a testcase and runs it from 1 through to n parallel copies to see if the testcase will scale. It builds both a process and threads based test in order to see any differences between the two.
> test-url: https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgithub.com%2Fantonblanchard%2Fwill-it-scale&data=02%7C01%7Cnamit%40vmware.com%7Cdfe19d72eecd46a93fc508d70b65652b%7Cb39138ca3cee4b4aa4d6cd83d9dd62f0%7C0%7C0%7C636990402460329367&sdata=YmsJebf0t3yyo7KMCdUu6VIOysebmB%2Fc7huxkOe5cV0%3D&reserved=0
I don’t understand how this patch has any impact on this workload.
I ran it and set a function tracer for any function that is impacted by this
patch:
# cd /sys/kernel/debug/tracing
# echo text_poke_early > set_ftrace_filter
# echo module_alloc >> set_ftrace_filter
# echo bpf_int_jit_compile >> set_ftrace_filter
# tail -f trace
Nothing came up. Can you please check if you see any of them invoked on your
setup? Perhaps you have some bpf filters being installed, although even then
this is a one-time (small) overhead for each process invocation.
next prev parent reply other threads:[~2019-07-18 17:59 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-18 9:50 kernel test robot
2019-07-18 17:59 ` Nadav Amit [this message]
2019-07-19 17:05 ` Dave Hansen
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=52D013BF-9B4B-4D03-B56F-3F378E4A2BA4@vmware.com \
--to=namit@vmware.com \
--cc=bp@alien8.de \
--cc=dave.hansen@intel.com \
--cc=hpa@zytor.com \
--cc=jeyu@kernel.org \
--cc=keescook@chromium.org \
--cc=linux-kernel@vger.kernel.org \
--cc=lkp@01.org \
--cc=luto@amacapital.net \
--cc=luto@kernel.org \
--cc=mhiramat@kernel.org \
--cc=mingo@kernel.org \
--cc=peterz@infradead.org \
--cc=rick.p.edgecombe@intel.com \
--cc=riel@surriel.com \
--cc=rong.a.chen@intel.com \
--cc=tglx@linutronix.de \
--cc=torvalds@linux-foundation.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox
all inboxes | Powered by JetHome®