linux-kernel - Re: [PATCH] VM: Implements the swap-out page-clustering technique

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: <20080910133941.61ceb087@bree.surriel.com>
Date:	Wed, 10 Sep 2008 13:39:41 -0400
From:	Rik van Riel <riel@...hat.com>
To:	"Ray Lee" <ray-lk@...rabbit.org>
Cc:	hamid.jahanjou@...il.com, "Zan Lynx" <zlynx@....org>,
	"Andi Kleen" <andi@...stfloor.org>, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] VM: Implements the swap-out page-clustering technique

On Wed, 10 Sep 2008 10:08:07 -0700
"Ray Lee" <ray-lk@...rabbit.org> wrote:
> On Wed, Sep 10, 2008 at 1:16 AM, Hamid R. Jahanjou
> <hamid.jahanjou@...il.com> wrote:
> > I agree. As you said, we have two conflicting requirements here: on the
> > one hand one likes to swap as many pages as to satisfy the backing
> > storage "proper block IO size," on the other hand, one should not make a
> > process lose too many pages.
> 
> I'd much rather that one process lose a lot of pages than many
> processes lose a few. When a system is swap thrashing, each process
> has some of its active working set tossed to swap, which means *any*
> application you try to switch to is then sluggish. If it were only one
> application, then only that one takes the penalty hit when the user
> switches focus and context.

Better still, with proper IO clustering that one process can get
its pages back into memory quite quickly.

Paging of anonymous pages is limited by disk seeks, so minimizing
those is a top goal.

-- 
All rights reversed.
--
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/