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From: Thomas Gleixner <tglx@linutronix.de>
To: lkp@lists.01.org
Subject: Re: [x86/signal] 3aac3ebea0: will-it-scale.per_thread_ops -11.9% regression
Date: Tue, 07 Dec 2021 21:36:31 +0100	[thread overview]
Message-ID: <875ys02lv4.ffs@tglx> (raw)
In-Reply-To: <81783AEA-1313-4353-837D-8217DEF3B9A2@intel.com>

[-- Attachment #1: Type: text/plain, Size: 958 bytes --]

On Tue, Dec 07 2021 at 18:49, Chang Seok Bae wrote:
> On Dec 7, 2021, at 05:38, Thomas Gleixner <tglx@linutronix.de> wrote:
>> On Tue, Dec 07 2021 at 09:21, kernel test robot wrote:
>>> (please be noted we made some further analysis before reporting out,
>>> and thought it's likely the regression is related with the extra spinlock
>>> introducded by enalbling DYNAMIC_SIGFRAME. below is the full report.)
>>> 
>>> FYI, we noticed a -11.9% regression of will-it-scale.per_thread_ops due to commit:
>> 
>> Does that use sigaltstack() ?
>
> FWIW, I was also wondering about this with:
>
> $ git clone https://github.com/antonblanchard/will-it-scale.git
> $ cd will-it-scale/
> $ git grep sigaltstack
> $
>
> But, the test seems to use python via runtest.py. And the python code has
> sigaltstack():
>     https://github.com/python/cpython/blob/main/Modules/faulthandler.c#L454

But how does that affect the test written in C? Mysterious!

WARNING: multiple messages have this Message-ID (diff)
From: Thomas Gleixner <tglx@linutronix.de>
To: "Bae, Chang Seok" <chang.seok.bae@intel.com>
Cc: "Sang, Oliver" <oliver.sang@intel.com>,
	Borislav Petkov <bp@suse.de>, LKML <linux-kernel@vger.kernel.org>,
	"lkp@lists.01.org" <lkp@lists.01.org>, lkp <lkp@intel.com>,
	"Huang, Ying" <ying.huang@intel.com>,
	"Tang, Feng" <feng.tang@intel.com>,
	"zhengjun.xing@linux.intel.com" <zhengjun.xing@linux.intel.com>,
	"Yin, Fengwei" <fengwei.yin@intel.com>
Subject: Re: [x86/signal]  3aac3ebea0:  will-it-scale.per_thread_ops -11.9% regression
Date: Tue, 07 Dec 2021 21:36:31 +0100	[thread overview]
Message-ID: <875ys02lv4.ffs@tglx> (raw)
In-Reply-To: <81783AEA-1313-4353-837D-8217DEF3B9A2@intel.com>

On Tue, Dec 07 2021 at 18:49, Chang Seok Bae wrote:
> On Dec 7, 2021, at 05:38, Thomas Gleixner <tglx@linutronix.de> wrote:
>> On Tue, Dec 07 2021 at 09:21, kernel test robot wrote:
>>> (please be noted we made some further analysis before reporting out,
>>> and thought it's likely the regression is related with the extra spinlock
>>> introducded by enalbling DYNAMIC_SIGFRAME. below is the full report.)
>>> 
>>> FYI, we noticed a -11.9% regression of will-it-scale.per_thread_ops due to commit:
>> 
>> Does that use sigaltstack() ?
>
> FWIW, I was also wondering about this with:
>
> $ git clone https://github.com/antonblanchard/will-it-scale.git
> $ cd will-it-scale/
> $ git grep sigaltstack
> $
>
> But, the test seems to use python via runtest.py. And the python code has
> sigaltstack():
>     https://github.com/python/cpython/blob/main/Modules/faulthandler.c#L454

But how does that affect the test written in C? Mysterious!

  reply	other threads:[~2021-12-07 20:36 UTC|newest]

Thread overview: 28+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-12-07  1:21 [x86/signal] 3aac3ebea0: will-it-scale.per_thread_ops -11.9% regression kernel test robot
2021-12-07  1:21 ` kernel test robot
2021-12-07  1:44 ` Oliver Sang
2021-12-07  1:44   ` Oliver Sang
2021-12-07 13:38 ` Thomas Gleixner
2021-12-07 13:38   ` Thomas Gleixner
2021-12-07 18:49   ` Bae, Chang Seok
2021-12-07 18:49     ` Bae, Chang Seok
2021-12-07 20:36     ` Thomas Gleixner [this message]
2021-12-07 20:36       ` Thomas Gleixner
2021-12-07 22:17       ` Bae, Chang Seok
2021-12-07 22:17         ` Bae, Chang Seok
2021-12-08  0:59         ` Yin Fengwei
2021-12-08  0:59           ` Yin Fengwei
2021-12-09  2:30   ` Carel Si
2021-12-09  2:30     ` [LKP] " Carel Si
2021-12-07 23:14 ` Dave Hansen
2021-12-07 23:14   ` Dave Hansen
2021-12-08 18:00   ` Bae, Chang Seok
2021-12-08 18:00     ` Bae, Chang Seok
2021-12-08 18:20     ` Dave Hansen
2021-12-08 18:20       ` Dave Hansen
2021-12-08 19:14       ` Thomas Gleixner
2021-12-08 19:14         ` Thomas Gleixner
2021-12-09  8:13       ` Thomas Gleixner
2021-12-09  8:13         ` Thomas Gleixner
2021-12-10  4:15   ` Carel Si
2021-12-10  4:15     ` [LKP] " Carel Si

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