From: "Rafael J. Wysocki" <rjw@sisk.pl>
To: Pavel Machek <pavel@ucw.cz>
Subject: Re: [RFC/RFT][PATCH -mm] swsusp: improve memory shrinking
Date: Mon, 27 Feb 2006 01:13:59 +0100
User-Agent: KMail/1.9.1
Cc: kernel list <linux-kernel@vger.kernel.org>
References: <20060201113710.6320.68289.stgit@localhost.localdomain> <200602270038.41287.rjw@sisk.pl> <20060226235614.GE2396@elf.ucw.cz>
In-Reply-To: <20060226235614.GE2396@elf.ucw.cz>
MIME-Version: 1.0
Content-Type: text/plain;
  charset="iso-8859-1"
Content-Transfer-Encoding: 7bit
Content-Disposition: inline
Message-Id: <200602270113.59817.rjw@sisk.pl>
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 2121
Lines: 49

On Monday 27 February 2006 00:56, Pavel Machek wrote:
> On Po 27-02-06 00:38:40, Rafael J. Wysocki wrote:
> > On Monday 27 February 2006 00:32, Rafael J. Wysocki wrote:
> > > On Sunday 26 February 2006 19:53, Pavel Machek wrote:
> > > > > > > > I did try shrink_all_memory() five times, with .5 second delay between
> > > > > > > > them, and it freed more memory at later tries.
> > > > > > > 
> > > > > > > I wonder if the delays are essential or if so, whether they may be shorter
> > > > > > > than .5 sec.
> > > > > > 
> > > > > > I was using this with some success... (Warning, against old
> > > > > > kernel). But, as I said, I consider it ugly, and it would be better to
> > > > > > fix shrink_all_memory.
> > > > > 
> > > > > Appended is a patch against the current -mm.
> > > > >   [It also makes
> > > > > swsusp_shrink_memory() behave as documented for image_size = 0.
> > > > > Currently, if it states there's enough free RAM to suspend, it won't bother
> > > > > to free a single page.]
> > > > 
> > > > Could we get bugfix part separately?
> > > 
> > > Sure.  Appended is the bugfix (I haven't tested it separately yet, but I think
> > > it's simple enough) ...
> > 
> > ... and this is the workaround of the "shrink_all_memory() returns 0 prematurely"
> > problem (not tested separately yet).  [Together these patches make my box
> > actually free more memory when image_size = 0.]
> 
> He he, move the workaround into mm/vmscan.c to get Andrew's attetion
> then attempt to push it :-))). That way
> 
> 1) shrink_all_memory() will get fixed for all callers
> 
> 2) you'll probably force akpm to fix it the right way :-).

Well, it looks like there are only two users of shrink_all_memory(), swsusp.c
and kernel/power/main.c, so we can change its behavior.

I think I'll leave swsusp.c as is and change shrink_all_memory() to
"try harder". ;-)

Greetings,
Rafael
-
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/