From: Michel Lespinasse <walken@google.com>
To: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org,
Andrew Morton <akpm@linux-foundation.org>,
Dave Hansen <dave@linux.vnet.ibm.com>,
Rik van Riel <riel@redhat.com>,
Balbir Singh <bsingharora@gmail.com>,
Peter Zijlstra <a.p.zijlstra@chello.nl>,
Andrea Arcangeli <aarcange@redhat.com>,
Johannes Weiner <jweiner@redhat.com>,
KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>,
Hugh Dickins <hughd@google.com>, Michael Wolf <mjwolf@us.ibm.com>
Subject: Re: [PATCH 6/9] kstaled: rate limit pages scanned per second.
Date: Wed, 28 Sep 2011 01:19:50 -0700 [thread overview]
Message-ID: <CANN689GFE_hqtndKY6i4ouBBe+gVU_pqOK2HRrc-U1LJMONaXw@mail.gmail.com> (raw)
In-Reply-To: <20110928171309.b45c684f.kamezawa.hiroyu@jp.fujitsu.com>
On Wed, Sep 28, 2011 at 1:13 AM, KAMEZAWA Hiroyuki
<kamezawa.hiroyu@jp.fujitsu.com> wrote:
> On Tue, 27 Sep 2011 17:49:04 -0700
> Michel Lespinasse <walken@google.com> wrote:
>
>> Scan some number of pages from each node every second, instead of trying to
>> scan the entime memory at once and being idle for the rest of the configured
>> interval.
>>
>> In addition to spreading the CPU usage over the entire scanning interval,
>> this also reduces the jitter between two consecutive scans of the same page.
>>
>>
>> Signed-off-by: Michel Lespinasse <walken@google.com>
>
> Does this scan thread need to be signle thread ?
It tends to perform worse if we try making it multithreaded. What
happens is that the scanning threads call page_referenced() a lot, and
if they both try scanning pages that belong to the same file that
causes the mapping's i_mmap_mutex lock to bounce. Same things happens
if they try scanning pages that belong to the same anon VMA too.
--
Michel "Walken" Lespinasse
A program is never fully debugged until the last user dies.
--
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next prev parent reply other threads:[~2011-09-28 8:19 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-09-28 0:48 [PATCH 0/9] V2: idle page tracking / working set estimation Michel Lespinasse
2011-09-28 0:48 ` [PATCH 1/9] page_referenced: replace vm_flags parameter with struct page_referenced_info Michel Lespinasse
2011-09-28 6:28 ` KAMEZAWA Hiroyuki
2011-09-28 0:49 ` [PATCH 2/9] kstaled: documentation and config option Michel Lespinasse
2011-09-28 6:53 ` KAMEZAWA Hiroyuki
2011-09-28 23:48 ` Michel Lespinasse
2011-09-29 5:40 ` KAMEZAWA Hiroyuki
2011-09-28 0:49 ` [PATCH 3/9] kstaled: page_referenced_kstaled() and supporting infrastructure Michel Lespinasse
2011-09-28 7:18 ` KAMEZAWA Hiroyuki
2011-09-29 0:09 ` Michel Lespinasse
2011-09-28 0:49 ` [PATCH 4/9] kstaled: minimalistic implementation Michel Lespinasse
2011-09-28 7:41 ` Peter Zijlstra
2011-09-28 8:01 ` Michel Lespinasse
2011-09-28 10:26 ` Peter Zijlstra
2011-09-28 8:00 ` KAMEZAWA Hiroyuki
2012-02-20 9:17 ` Zhu Yanhai
2011-09-28 0:49 ` [PATCH 5/9] kstaled: skip non-RAM regions Michel Lespinasse
2011-09-28 8:03 ` KAMEZAWA Hiroyuki
2011-09-28 0:49 ` [PATCH 6/9] kstaled: rate limit pages scanned per second Michel Lespinasse
2011-09-28 8:13 ` KAMEZAWA Hiroyuki
2011-09-28 8:19 ` Michel Lespinasse [this message]
2011-09-28 8:59 ` KAMEZAWA Hiroyuki
2011-10-14 1:25 ` Michel Lespinasse
2011-10-14 4:54 ` KAMEZAWA Hiroyuki
2011-09-28 0:49 ` [PATCH 7/9] kstaled: add histogram sampling functionality Michel Lespinasse
2011-09-28 8:22 ` KAMEZAWA Hiroyuki
2011-09-28 0:49 ` [PATCH 8/9] kstaled: add incrementally updating stale page count Michel Lespinasse
2011-09-28 0:49 ` [PATCH 9/9] kstaled: export PG_stale in /proc/kpageflags Michel Lespinasse
2011-09-29 16:43 ` [PATCH 0/9] V2: idle page tracking / working set estimation Eric B Munson
2011-09-29 20:25 ` Michel Lespinasse
2011-09-29 21:18 ` Eric B Munson
2011-09-30 18:19 ` Eric B Munson
2011-09-30 21:16 ` Michel Lespinasse
2011-09-30 21:40 ` Eric B Munson
2011-10-03 15:06 ` Eric B Munson
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