From: Catalin Marinas <catalin.marinas@arm.com>
To: lkp@lists.01.org
Subject: Re: [futex] 76835b0ebf8: -8.1% will-it-scale.per_thread_ops
Date: Thu, 26 Feb 2015 09:58:13 +0000 [thread overview]
Message-ID: <20150226095812.GA32538@localhost> (raw)
In-Reply-To: <1424927813.10337.19.camel@intel.com>
[-- Attachment #1: Type: text/plain, Size: 1038 bytes --]
On Thu, Feb 26, 2015 at 05:16:53AM +0000, Huang Ying wrote:
> FYI, we noticed the below changes on
>
> git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
> commit 76835b0ebf8a7fe85beb03c75121419a7dec52f0 ("futex: Ensure get_futex_key_refs() always implies a barrier")
>
>
> testbox/testcase/testparams: lkp-wsx01/will-it-scale/performance-futex4
>
> 0429fbc0bdc297d6 76835b0ebf8a7fe85beb03c751
> ---------------- --------------------------
> %stddev %change %stddev
> \ | \
> 6314259 ± 0% -8.1% 5800079 ± 0% will-it-scale.per_thread_ops
> 6274871 ± 0% -8.1% 5768747 ± 0% will-it-scale.per_process_ops
This was raised before but I'm not sure we can do much about it:
https://lkml.org/lkml/2014/10/26/189
It would be interesting to know the difference in performance with the
code prior to commits b0c29f79ecea and 11d4616bd07f which optimised the
futex code but missed a barrier.
--
Catalin
WARNING: multiple messages have this Message-ID (diff)
From: Catalin Marinas <catalin.marinas@arm.com>
To: Huang Ying <ying.huang@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
LKML <linux-kernel@vger.kernel.org>, LKP ML <lkp@01.org>
Subject: Re: [LKP] [futex] 76835b0ebf8: -8.1% will-it-scale.per_thread_ops
Date: Thu, 26 Feb 2015 09:58:13 +0000 [thread overview]
Message-ID: <20150226095812.GA32538@localhost> (raw)
In-Reply-To: <1424927813.10337.19.camel@intel.com>
On Thu, Feb 26, 2015 at 05:16:53AM +0000, Huang Ying wrote:
> FYI, we noticed the below changes on
>
> git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
> commit 76835b0ebf8a7fe85beb03c75121419a7dec52f0 ("futex: Ensure get_futex_key_refs() always implies a barrier")
>
>
> testbox/testcase/testparams: lkp-wsx01/will-it-scale/performance-futex4
>
> 0429fbc0bdc297d6 76835b0ebf8a7fe85beb03c751
> ---------------- --------------------------
> %stddev %change %stddev
> \ | \
> 6314259 ± 0% -8.1% 5800079 ± 0% will-it-scale.per_thread_ops
> 6274871 ± 0% -8.1% 5768747 ± 0% will-it-scale.per_process_ops
This was raised before but I'm not sure we can do much about it:
https://lkml.org/lkml/2014/10/26/189
It would be interesting to know the difference in performance with the
code prior to commits b0c29f79ecea and 11d4616bd07f which optimised the
futex code but missed a barrier.
--
Catalin
next prev parent reply other threads:[~2015-02-26 9:58 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-02-26 5:16 [futex] 76835b0ebf8: -8.1% will-it-scale.per_thread_ops Huang Ying
2015-02-26 5:16 ` [LKP] " Huang Ying
2015-02-26 9:58 ` Catalin Marinas [this message]
2015-02-26 9:58 ` Catalin Marinas
2015-02-27 3:28 ` Huang Ying
2015-02-27 3:28 ` [LKP] " Huang Ying
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