From: "Pádraig Brady" <P@draigBrady.com>
To: Alex Shi <alex.shi@intel.com>
Cc: linux-mm@kvack.org, mgorman@suse.de,
linux-kernel@vger.kernel.org, andrea@cpushare.com,
tim.c.chen@intel.com, shaohua.li@intel.com,
akpm@linux-foundation.org, riel@redhat.com, luto@mit.edu
Subject: Re: [PATCH] kswapd: avoid unnecessary rebalance after an unsuccessful balancing
Date: Fri, 29 Jul 2011 19:21:49 +0100 [thread overview]
Message-ID: <4E32FA3D.5060100@draigBrady.com> (raw)
In-Reply-To: <1311952990-3844-1-git-send-email-alex.shi@intel.com>
On 07/29/2011 04:23 PM, Alex Shi wrote:
> In commit 215ddd66, Mel Gorman said kswapd is better to sleep after a
> unsuccessful balancing if there is tighter reclaim request pending in
> the balancing. In this scenario, the 'order' and 'classzone_idx'
> that are checked for tighter request judgment is incorrect, since they
> aren't the one kswapd should read from new pgdat, but the last time pgdat
> value for just now balancing. Then kswapd will skip try_to_sleep func
> and rebalance the last pgdat request. It's not our expected behavior.
>
> So, I added new variables to distinguish the returned order/classzone_idx
> from last balancing, that can resolved above issue in that scenario.
>
> I tested the patch on our LKP system with swap-cp/fio mmap randrw
> benchmarks. The performance has no change.
>
> Padraig Brady, would you like to test this patch for your scenario.
This
+ your previous 2 line patch
+ Mel's 3 patches
+ 2.6.38.4
still works fine for me.
cheers,
Pádraig.
WARNING: multiple messages have this Message-ID (diff)
From: "Pádraig Brady" <P@draigBrady.com>
To: Alex Shi <alex.shi@intel.com>
Cc: linux-mm@kvack.org, mgorman@suse.de,
linux-kernel@vger.kernel.org, andrea@cpushare.com,
tim.c.chen@intel.com, shaohua.li@intel.com,
akpm@linux-foundation.org, riel@redhat.com, luto@mit.edu
Subject: Re: [PATCH] kswapd: avoid unnecessary rebalance after an unsuccessful balancing
Date: Fri, 29 Jul 2011 19:21:49 +0100 [thread overview]
Message-ID: <4E32FA3D.5060100@draigBrady.com> (raw)
In-Reply-To: <1311952990-3844-1-git-send-email-alex.shi@intel.com>
On 07/29/2011 04:23 PM, Alex Shi wrote:
> In commit 215ddd66, Mel Gorman said kswapd is better to sleep after a
> unsuccessful balancing if there is tighter reclaim request pending in
> the balancing. In this scenario, the 'order' and 'classzone_idx'
> that are checked for tighter request judgment is incorrect, since they
> aren't the one kswapd should read from new pgdat, but the last time pgdat
> value for just now balancing. Then kswapd will skip try_to_sleep func
> and rebalance the last pgdat request. It's not our expected behavior.
>
> So, I added new variables to distinguish the returned order/classzone_idx
> from last balancing, that can resolved above issue in that scenario.
>
> I tested the patch on our LKP system with swap-cp/fio mmap randrw
> benchmarks. The performance has no change.
>
> Padraig Brady, would you like to test this patch for your scenario.
This
+ your previous 2 line patch
+ Mel's 3 patches
+ 2.6.38.4
still works fine for me.
cheers,
Padraig.
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next prev parent reply other threads:[~2011-07-29 18:31 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-07-29 15:23 [PATCH] kswapd: avoid unnecessary rebalance after an unsuccessful balancing Alex Shi
2011-07-29 15:23 ` Alex Shi
2011-07-29 15:40 ` Mel Gorman
2011-07-29 15:40 ` Mel Gorman
2011-08-01 0:45 ` Alex,Shi
2011-08-01 0:45 ` Alex,Shi
2011-08-02 10:22 ` Mel Gorman
2011-08-02 10:22 ` Mel Gorman
2011-08-03 0:49 ` Alex,Shi
2011-08-03 0:49 ` Alex,Shi
2011-07-29 18:21 ` Pádraig Brady [this message]
2011-07-29 18:21 ` Pádraig Brady
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