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From: Borislav Petkov <bp@alien8.de>
To: lkp@lists.01.org
Subject: Re: [x86/copy_user] adb402cd14: will-it-scale.per_process_ops -12.7% regression
Date: Wed, 09 Nov 2016 13:42:14 +0100	[thread overview]
Message-ID: <20161109124214.sjasqcurv6gi64ol@pd.tnic> (raw)
In-Reply-To: <20161107025038.GE21529@yexl-desktop>

[-- Attachment #1: Type: text/plain, Size: 1265 bytes --]

On Mon, Nov 07, 2016 at 10:50:38AM +0800, kernel test robot wrote:
> 
> Greeting,
> 
> FYI, we noticed a -12.7% regression of will-it-scale.per_process_ops due to commit:
> 
> 
> commit adb402cd1461eef6e1a21db4532a3b9e6a6be853 ("x86/copy_user: Unify the code by removing the 64-bit asm _copy_*_user() variants")
> https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git x86/asm
> 
> in testcase: will-it-scale
> on test machine: 8 threads Intel(R) Core(TM) i7 CPU 870 @ 2.93GHz with 4G memory
> with following parameters:
> 
> 	test: poll1
> 	cpufreq_governor: performance

...

> # Lock Debugging (spinlocks, mutexes, etc...)
> #
> # CONFIG_DEBUG_RT_MUTEXES is not set
> # CONFIG_DEBUG_SPINLOCK is not set
> # CONFIG_DEBUG_MUTEXES is not set
> # CONFIG_DEBUG_WW_MUTEX_SLOWPATH is not set
> # CONFIG_DEBUG_LOCK_ALLOC is not set
> # CONFIG_PROVE_LOCKING is not set
> # CONFIG_LOCK_STAT is not set
> CONFIG_DEBUG_ATOMIC_SLEEP=y
  ^^^^^^^^^^^^^^^^^^^^^^^^^

So Mel says that this might be the culprit for the observed
change in perf. Can you please rerun your test without that
CONFIG_DEBUG_ATOMIC_SLEEP thing?

Thanks.

-- 
Regards/Gruss,
    Boris.

Good mailing practices for 400: avoid top-posting and trim the reply.

WARNING: multiple messages have this Message-ID (diff)
From: Borislav Petkov <bp@alien8.de>
To: kernel test robot <xiaolong.ye@intel.com>
Cc: Ingo Molnar <mingo@kernel.org>, Andy Lutomirski <luto@kernel.org>,
	Brian Gerst <brgerst@gmail.com>,
	Denys Vlasenko <dvlasenk@redhat.com>,
	"H. Peter Anvin" <hpa@zytor.com>,
	Josh Poimboeuf <jpoimboe@redhat.com>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Peter Zijlstra <peterz@infradead.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	LKML <linux-kernel@vger.kernel.org>,
	tipbuild@zytor.com, lkp@01.org,
	Mel Gorman <mgorman@techsingularity.net>
Subject: Re: [lkp] [x86/copy_user]  adb402cd14: will-it-scale.per_process_ops -12.7% regression
Date: Wed, 9 Nov 2016 13:42:14 +0100	[thread overview]
Message-ID: <20161109124214.sjasqcurv6gi64ol@pd.tnic> (raw)
In-Reply-To: <20161107025038.GE21529@yexl-desktop>

On Mon, Nov 07, 2016 at 10:50:38AM +0800, kernel test robot wrote:
> 
> Greeting,
> 
> FYI, we noticed a -12.7% regression of will-it-scale.per_process_ops due to commit:
> 
> 
> commit adb402cd1461eef6e1a21db4532a3b9e6a6be853 ("x86/copy_user: Unify the code by removing the 64-bit asm _copy_*_user() variants")
> https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git x86/asm
> 
> in testcase: will-it-scale
> on test machine: 8 threads Intel(R) Core(TM) i7 CPU 870 @ 2.93GHz with 4G memory
> with following parameters:
> 
> 	test: poll1
> 	cpufreq_governor: performance

...

> # Lock Debugging (spinlocks, mutexes, etc...)
> #
> # CONFIG_DEBUG_RT_MUTEXES is not set
> # CONFIG_DEBUG_SPINLOCK is not set
> # CONFIG_DEBUG_MUTEXES is not set
> # CONFIG_DEBUG_WW_MUTEX_SLOWPATH is not set
> # CONFIG_DEBUG_LOCK_ALLOC is not set
> # CONFIG_PROVE_LOCKING is not set
> # CONFIG_LOCK_STAT is not set
> CONFIG_DEBUG_ATOMIC_SLEEP=y
  ^^^^^^^^^^^^^^^^^^^^^^^^^

So Mel says that this might be the culprit for the observed
change in perf. Can you please rerun your test without that
CONFIG_DEBUG_ATOMIC_SLEEP thing?

Thanks.

-- 
Regards/Gruss,
    Boris.

Good mailing practices for 400: avoid top-posting and trim the reply.

  parent reply	other threads:[~2016-11-09 12:42 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-11-07  2:50 [x86/copy_user] adb402cd14: will-it-scale.per_process_ops -12.7% regression kernel test robot
2016-11-07  2:50 ` [lkp] " kernel test robot
2016-11-07  9:56 ` Borislav Petkov
2016-11-07  9:56   ` [lkp] " Borislav Petkov
2016-11-14 14:37   ` Ye Xiaolong
2016-11-15 10:01     ` Borislav Petkov
2016-11-14 14:19       ` Ye Xiaolong
2016-11-15 15:10         ` Borislav Petkov
2016-11-16  9:58         ` Borislav Petkov
2016-11-16 12:38           ` Ye Xiaolong
2016-11-09 12:42 ` Borislav Petkov [this message]
2016-11-09 12:42   ` [lkp] " Borislav Petkov

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