linux-kernel - Re: [x86/copy_mc] a0ac629ebe: fio.read

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20200806133452.GA2077191@gmail.com>
Date:   Thu, 6 Aug 2020 15:34:52 +0200
From:   Ingo Molnar <mingo@...nel.org>
To:     kernel test robot <rong.a.chen@...el.com>,
        Dan Williams <dan.j.williams@...el.com>
Cc:     Dan Williams <dan.j.williams@...el.com>, tglx@...utronix.de,
        mingo@...hat.com, vishal.l.verma@...el.com, x86@...nel.org,
        stable@...r.kernel.org, Borislav Petkov <bp@...en8.de>,
        Vivek Goyal <vgoyal@...hat.com>,
        "H. Peter Anvin" <hpa@...or.com>,
        Andy Lutomirski <luto@...nel.org>,
        Peter Zijlstra <peterz@...radead.org>,
        Linus Torvalds <torvalds@...ux-foundation.org>,
        Tony Luck <tony.luck@...el.com>,
        Erwin Tsaur <erwin.tsaur@...el.com>, linux-nvdimm@...ts.01.org,
        linux-kernel@...r.kernel.org, 0day robot <lkp@...el.com>,
        lkp@...ts.01.org
Subject: Re: [x86/copy_mc] a0ac629ebe: fio.read_iops -43.3% regression


* kernel test robot <rong.a.chen@...el.com> wrote:

> Greeting,
> 
> FYI, we noticed a -43.3% regression of fio.read_iops due to commit:
> 
> 
> commit: a0ac629ebe7b3d248cb93807782a00d9142fdb98 ("x86/copy_mc: Introduce copy_mc_generic()")
> url: https://github.com/0day-ci/linux/commits/Dan-Williams/Renovate-memcpy_mcsafe-with-copy_mc_to_-user-kernel/20200802-014046
> 
> 
> in testcase: fio-basic
> on test machine: 96 threads Intel(R) Xeon(R) Gold 6252 CPU @ 2.10GHz with 256G memory
> with following parameters:

So this performance regression, if it isn't a spurious result, looks 
concerning. Is this expected?

Thanks,

	Ingo