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]
Date:   Tue, 25 Aug 2020 16:44:37 +0000
From:   "Luck, Tony" <tony.luck@...el.com>
To:     "Tang, Feng" <feng.tang@...el.com>, Borislav Petkov <bp@...e.de>
CC:     "Chen, Rong A" <rong.a.chen@...el.com>,
        LKML <linux-kernel@...r.kernel.org>,
        "lkp@...ts.01.org" <lkp@...ts.01.org>,
        "Mel Gorman" <mgorman@...e.com>
Subject: RE: [LKP] Re: [x86/mce] 1de08dccd3: will-it-scale.per_process_ops
 -14.1% regression

> These 2 variables are accessed in 2 hot call stacks (for this 288 CPU
> Xeon Phi platform):

This might be the key element of "weirdness" for this system. It
has 288 CPUs ... cache alignment problems are often not too bad
on "small" systems. The as you scale up to bigger machines you
suddenly hit some critical point and performance drops dramatically.

It's good that you are picking up tips on how to bisect these and diagnose
the underlying problem. Number of cores is going to keep increasing, so
we will keep finding new issues like this.

-Tony

Powered by blists - more mailing lists