| 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
| ||
|
Date: Thu, 09 Jul 2009 04:54:10 +0000 (GMT)
From: NARAYANAN GOPALAKRISHNAN <narayanan.g@...sung.com>
To: Andrew Morton <akpm@...ux-foundation.org>,
Mel Gorman <mel@....ul.ie>
Cc: "kamezawa.hiroyu@...fujitsu.com" <kamezawa.hiroyu@...fujitsu.com>,
"linux-mm@...ck.org" <linux-mm@...ck.org>,
"cl@...ux-foundation.org" <cl@...ux-foundation.org>,
"kosaki.motohiro@...fujitsu.com" <kosaki.motohiro@...fujitsu.com>,
"stable@...nel.org" <stable@...nel.org>,
"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
"linux-scsi@...r.kernel.org" <linux-scsi@...r.kernel.org>
Subject: Re: Re: Performance degradation seen after using one list for hot/cold
pages.
> I'll add the rather important text:
>
> Fix a post-2.6.24 performance regression caused by
> 3dfa5721f12c3d5a441448086bee156887daa961 ("page-allocator: preserve PFN
> ordering when __GFP_COLD is set").
>
> This was a pretty major screwup.
>
> This is why changing core MM is so worrisome - there's so much secret and
> subtle history to it, and performance dependencies are unobvious and quite
> indirect and the lag time to discover regressions is long.
>
> Narayanan, are you able to quantify the regression more clearly? All I
> have is "2 MBps lower" which isn't very useful. What is this as a
> percentage, and with what sort of disk controller? Thanks.
It is around 15%. There is no disk controller as our setup is based on Samsung OneNAND
used as a memory mapped device on a OMAP2430 based board.
Narayanan
Powered by blists - more mailing lists