linux-kernel - Re: [PATCH 1/4] vmscan: simplify shrink_inactive

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20100415154442.GG10966@csn.ul.ie>
Date:	Thu, 15 Apr 2010 16:44:42 +0100
From:	Mel Gorman <mel@....ul.ie>
To:	Andi Kleen <andi@...stfloor.org>
Cc:	KOSAKI Motohiro <kosaki.motohiro@...fujitsu.com>,
	Dave Chinner <david@...morbit.com>,
	Chris Mason <chris.mason@...cle.com>,
	linux-kernel@...r.kernel.org, linux-mm@...ck.org,
	linux-fsdevel@...r.kernel.org
Subject: Re: [PATCH 1/4] vmscan: simplify shrink_inactive_list()

On Thu, Apr 15, 2010 at 05:01:36PM +0200, Andi Kleen wrote:
> Mel Gorman <mel@....ul.ie> writes:
> >
> > $ stack-o-meter vmlinux-vanilla vmlinux-2-simplfy-shrink 
> > add/remove: 0/0 grow/shrink: 0/2 up/down: 0/-144 (-144)
> > function                                     old     new   delta
> > shrink_zone                                 1232    1160     -72
> > kswapd                                       748     676     -72
> 
> And the next time someone adds a new feature to these code paths or
> the compiler inlines differently these 72 bytes are easily there
> again. It's not really a long term solution. Code is tending to get
> more complicated all the time. I consider it unlikely this trend will
> stop any time soon.
> 

The same logic applies when/if page writeback is split so that it is
handled by a separate thread.

> So just doing some stack micro optimizations doesn't really help 
> all that much.
> 

It's a buying-time venture, I'll agree but as both approaches are only
about reducing stack stack they wouldn't be long-term solutions by your
criteria. What do you suggest?


-- 
Mel Gorman
Part-time Phd Student                          Linux Technology Center
University of Limerick                         IBM Dublin Software Lab
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/