lkml.org 
[lkml]   [2012]   [Apr]   [10]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH 1/2] mm: vmscan: Remove lumpy reclaim
On Fri, Apr 06, 2012 at 04:52:09PM -0700, Ying Han wrote:
> On Wed, Mar 28, 2012 at 9:06 AM, Mel Gorman <mgorman@suse.de> wrote:
> > Lumpy reclaim had a purpose but in the mind of some, it was to kick
> > the system so hard it trashed. For others the purpose was to complicate
> > vmscan.c. Over time it was giving softer shoes and a nicer attitude but
> > memory compaction needs to step up and replace it so this patch sends
> > lumpy reclaim to the farm.
> >
> > Here are the important notes related to the patch.
> >
> > 1. The tracepoint format changes for isolating LRU pages.
> >
> > 2. This patch stops reclaim/compaction entering sync reclaim as this
> >   was only intended for lumpy reclaim and an oversight. Page migration
> >   has its own logic for stalling on writeback pages if necessary and
> >   memory compaction is already using it. This is a behaviour change.
> >
> > 3. RECLAIM_MODE_SYNC no longer exists. pageout() does not stall
> >   on PageWriteback with CONFIG_COMPACTION has been this way for a while.
> >   I am calling it out in case this is a surpise to people.
>
> Mel,
>
> Can you point me the commit making that change? I am looking at
> v3.4-rc1 where set_reclaim_mode() still set RECLAIM_MODE_SYNC for
> COMPACTION_BUILD.
>

You're right.

There is only one call site that passes sync==true for set_reclaim_mode() in
vmscan.c and that is only if should_reclaim_stall() returns true. It had the
comment "Only stall on lumpy reclaim" but the comment is not accurate
and that mislead me.

Thanks, I'll revisit the patch.

--
Mel Gorman
SUSE Labs
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2012-04-10 10:27    [W:0.067 / U:0.192 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site