From: Rik van Riel <riel@redhat.com>
To: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, lee.shermerhorn@hp.com
Subject: Re: [patch 10/20] SEQ replacement for anonymous pages
Date: Wed, 19 Dec 2007 08:40:58 -0500 [thread overview]
Message-ID: <20071219084058.6ae3c531@bree.surriel.com> (raw)
In-Reply-To: <20071219140904.9858.KOSAKI.MOTOHIRO@jp.fujitsu.com>
On Wed, 19 Dec 2007 14:17:53 +0900
KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> wrote:
> Hi Rik-san,
>
> > To keep the maximum amount of necessary work reasonable, we scale the
> > active to inactive ratio with the size of memory, using the formula
> > active:inactive ratio = sqrt(memory in GB * 10).
> why do you think best formula is sqrt(GB*10)?
> please tell me if you don't mind.
On a 1GB system, this leads to a ratio of 3 active anon
pages to 1 inactive anon page, and a maximum inactive
anon list size of 250MB.
On a 1TB system, this leads to a ratio of 100 active anon
pages to 1 inactive anon page, and a maximum inactive
anon list size of 10GB.
The numbers in-between looked reasonable :)
Basically the requirement is that the inactive anon list
is large enough that pages get a chance to be referenced
again, but small enough that the maximum amount of work
the VM needs to do is bounded to something reasonable.
> and i have a bit worry to it works well or not on small systems.
> because it is indicate 1:1 ratio on less than 100MB memory system.
> Do you think this viewpoint?
A 1:1 ratio simply means that the inactive anon list is
the same size as the active anon list. Page replacement
should still work fine that way.
--
"Debugging is twice as hard as writing the code in the first place.
Therefore, if you write the code as cleverly as possible, you are,
by definition, not smart enough to debug it." - Brian W. Kernighan
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next prev parent reply other threads:[~2007-12-19 13:40 UTC|newest]
Thread overview: 59+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-12-18 21:15 [patch 00/20] VM pageout scalability improvements Rik van Riel
2007-12-18 21:15 ` [patch 01/20] convert anon_vma list lock a read/write lock Rik van Riel
2007-12-20 7:07 ` Christoph Lameter
2007-12-18 21:15 ` [patch 02/20] make the inode i_mmap_lock a reader/writer lock Rik van Riel
2007-12-19 0:48 ` Nick Piggin
2007-12-19 4:09 ` KOSAKI Motohiro
2007-12-19 15:52 ` Lee Schermerhorn
2007-12-19 16:31 ` Rik van Riel
2007-12-19 16:53 ` Lee Schermerhorn
2007-12-19 19:28 ` Peter Zijlstra
2007-12-19 23:40 ` Nick Piggin
2007-12-20 7:04 ` Christoph Lameter
2007-12-20 7:59 ` Nick Piggin
2008-01-02 23:35 ` Mike Travis
2008-01-03 6:07 ` Nick Piggin
2008-01-03 8:55 ` Ingo Molnar
2008-01-07 9:01 ` Nick Piggin
2007-12-18 21:15 ` [patch 03/20] move isolate_lru_page() to vmscan.c Rik van Riel
2007-12-20 7:08 ` Christoph Lameter
2007-12-18 21:15 ` [patch 04/20] free swap space on swap-in/activation Rik van Riel
2007-12-18 21:15 ` [patch 05/20] define page_file_cache() function Rik van Riel
2007-12-18 21:15 ` [patch 06/20] debugging checks for page_file_cache() Rik van Riel
2007-12-18 21:15 ` [patch 07/20] Use an indexed array for LRU variables Rik van Riel
2007-12-18 21:15 ` [patch 08/20] split LRU lists into anon & file sets Rik van Riel
2007-12-18 21:15 ` [patch 09/20] split anon & file LRUs for memcontrol code Rik van Riel
2007-12-18 21:15 ` [patch 10/20] SEQ replacement for anonymous pages Rik van Riel
2007-12-19 5:17 ` KOSAKI Motohiro
2007-12-19 13:40 ` Rik van Riel [this message]
2007-12-20 2:04 ` KOSAKI Motohiro
2007-12-18 21:15 ` [patch 11/20] add newly swapped in pages to the inactive list Rik van Riel
2007-12-18 21:15 ` [patch 12/20] No Reclaim LRU Infrastructure Rik van Riel
2007-12-18 21:15 ` [patch 13/20] Non-reclaimable page statistics Rik van Riel
2007-12-18 21:15 ` [patch 14/20] Scan noreclaim list for reclaimable pages Rik van Riel
2007-12-18 21:15 ` [patch 15/20] ramfs pages are non-reclaimable Rik van Riel
2007-12-18 21:15 ` [patch 16/20] SHM_LOCKED pages are nonreclaimable Rik van Riel
2007-12-18 21:15 ` [patch 17/20] non-reclaimable mlocked pages Rik van Riel
2007-12-19 0:56 ` Nick Piggin
2007-12-19 13:45 ` Rik van Riel
2007-12-19 14:24 ` Peter Zijlstra
2007-12-19 14:53 ` Rik van Riel
2007-12-19 16:08 ` Lee Schermerhorn
2007-12-19 16:04 ` Lee Schermerhorn
2007-12-20 20:56 ` Rik van Riel
2007-12-21 10:52 ` Nick Piggin
2007-12-21 14:17 ` Rik van Riel
2007-12-23 12:22 ` Nick Piggin
2007-12-24 1:00 ` Rik van Riel
2007-12-19 23:34 ` Nick Piggin
2007-12-20 7:19 ` Christoph Lameter
2007-12-20 15:33 ` Rik van Riel
2007-12-21 17:13 ` Lee Schermerhorn
2007-12-18 21:15 ` [patch 18/20] mlock vma pages under mmap_sem held for read Rik van Riel
2007-12-18 21:15 ` [patch 19/20] handle mlocked pages during map/unmap and truncate Rik van Riel
2007-12-18 21:15 ` [patch 20/20] account mlocked pages Rik van Riel
2007-12-22 20:27 ` [patch 00/20] VM pageout scalability improvements Balbir Singh
2007-12-23 0:21 ` Rik van Riel
2007-12-23 22:59 ` Balbir Singh
2007-12-24 1:11 ` Rik van Riel
2007-12-28 3:20 ` Matt Mackall
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