From: Feng Tang <feng.tang@intel.com>
To: "Luck, Tony" <tony.luck@intel.com>
Cc: Borislav Petkov <bp@suse.de>,
"Chen, Rong A" <rong.a.chen@intel.com>,
LKML <linux-kernel@vger.kernel.org>,
"lkp@lists.01.org" <lkp@lists.01.org>,
Mel Gorman <mgorman@suse.com>
Subject: Re: [LKP] Re: [x86/mce] 1de08dccd3: will-it-scale.per_process_ops -14.1% regression
Date: Wed, 26 Aug 2020 09:45:58 +0800 [thread overview]
Message-ID: <20200826014558.GC83850@shbuild999.sh.intel.com> (raw)
In-Reply-To: <b704f3c6298f46abbc59105ec0d52d14@intel.com>
On Wed, Aug 26, 2020 at 12:44:37AM +0800, Luck, Tony wrote:
> > 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.
Yes, now we have one more bullet for shooting this kind of strange
performance changes :)
Thanks,
Feng
> -Tony
next prev parent reply other threads:[~2020-08-26 1:46 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-25 11:44 [x86/mce] 1de08dccd3: will-it-scale.per_process_ops -14.1% regression kernel test robot
2020-04-25 13:01 ` Borislav Petkov
2020-08-18 8:29 ` [LKP] " Feng Tang
2020-08-18 20:06 ` Luck, Tony
2020-08-19 2:04 ` Feng Tang
2020-08-19 2:23 ` Luck, Tony
2020-08-19 3:04 ` Feng Tang
2020-08-19 3:15 ` Feng Tang
2020-08-21 2:02 ` Feng Tang
2020-08-24 15:14 ` Borislav Petkov
2020-08-24 15:33 ` Feng Tang
2020-08-24 15:38 ` Luck, Tony
2020-08-24 15:48 ` Feng Tang
2020-08-24 16:12 ` Borislav Petkov
2020-08-24 16:56 ` Mel Gorman
2020-08-25 6:49 ` Feng Tang
2020-08-25 6:23 ` Feng Tang
2020-08-25 16:44 ` Luck, Tony
2020-08-26 1:45 ` Feng Tang [this message]
2020-08-28 17:48 ` Borislav Petkov
2020-08-31 2:16 ` Feng Tang
2020-08-31 7:56 ` Mel Gorman
2020-08-31 8:23 ` Feng Tang
2020-08-31 8:55 ` Mel Gorman
2020-08-31 12:53 ` Feng Tang
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