linux-kernel - Re: [PATCH] Use extents for recording what swap is allocated.

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] [day] [month] [year] [list]

Message-Id: <1162415992.5737.8.camel@nigel.suspend2.net>
Date:	Thu, 02 Nov 2006 08:19:52 +1100
From:	Nigel Cunningham <ncunningham@...uxmail.org>
To:	Pavel Machek <pavel@....cz>
Cc:	Christoph Hellwig <hch@...radead.org>,
	Andrew Morton <akpm@...l.org>,
	"Rafael J. Wysocki" <rjw@...k.pl>,
	LKML <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] Use extents for recording what swap is allocated.

Hi.

On Wed, 2006-11-01 at 13:36 +0100, Pavel Machek wrote:
> > Hi.
> > 
> > On Tue, 2006-10-24 at 21:42 +0100, Christoph Hellwig wrote:
> > > On Mon, Oct 23, 2006 at 02:14:17PM +1000, Nigel Cunningham wrote:
> > > > Switch from bitmaps to using extents to record what swap is allocated;
> > > > they make more efficient use of memory, particularly where the allocated
> > > > storage is small and the swap space is large.
> > > >     
> > > > This is also part of the ground work for implementing support for
> > > > supporting multiple swap devices.
> > > 
> > > In addition to the very useful comments from Rafael there's some observations
> > > of my own:
> > > 
> > >  - there's an awful lot of opencoded list manipulation, any chance you
> > >    could use list.h instead?
> > 
> > Further to this, I gave using list.h a go. Unfortunately it doesn't look
> > to me like it is a good idea: in adding a range, I'm comparing the new
> > range to the maximum of one extent and the minimum of the next, so
> > finding the minimum of the next extent becomes a lot uglier than it
> > currently is. Currently it's just ->next->minimum, but with list.h, I'd
> > need container_of(current->list.next)->minimum. Or am I missing
> > something?
> 
> That does not look that scary... just do it.

It currently makes more sense to me to stick with what I already have
because it's simpler and more readable.

Regards,

Nigel

-
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/