From: "Rafael J. Wysocki" <rjw@sisk.pl>
To: Martin Steigerwald <Martin@lichtvoll.de>
Subject: Re: does hibernate to disk try hard enough to free memory?
Date: Sun, 6 Mar 2011 00:28:02 +0100
User-Agent: KMail/1.13.5 (Linux/2.6.38-rc7+; KDE/4.4.4; x86_64; ; )
Cc: linux-kernel@vger.kernel.org,
        Linux PM mailing list <linux-pm@lists.linux-foundation.org>
References: <201102222159.58546.Martin@lichtvoll.de> <201102232106.51980.rjw@sisk.pl> <201103051541.45511.Martin@lichtvoll.de>
In-Reply-To: <201103051541.45511.Martin@lichtvoll.de>
MIME-Version: 1.0
Content-Type: Text/Plain;
  charset="iso-8859-2"
Content-Transfer-Encoding: 7bit
Message-Id: <201103060028.02477.rjw@sisk.pl>
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 3012
Lines: 73

On Saturday, March 05, 2011, Martin Steigerwald wrote:
> Am Wednesday 23 February 2011 schrieb Rafael J. Wysocki:
> > On Wednesday, February 23, 2011, Martin Steigerwald wrote:
> > > Am Tuesday 22 February 2011 schrieb Rafael J. Wysocki:
> > > > On Tuesday, February 22, 2011, Martin Steigerwald wrote:
> > > > > Am Tuesday 22 February 2011 schrieb Rafael J. Wysocki:
> > > > > > On Tuesday, February 22, 2011, Martin Steigerwald wrote:
> > > > > > > Hi!
> > > > > > > 
> > > > > > > Since Radeon KMS I often have it that my ThinkPad T42 with 2
> > > > > > > MiB of RAM is not able to allocate memory for the
> > > > > > > hibernation image. Before KMS hibernation only very rarely
> > > > > > > failed for that reason.
> > > > > > > 
> > > > > > > Often I run without compositing at all as I believe this
> > > > > > > might spare some pages as well. But this doesn't always
> > > > > > > help.
> > > > > > > 
> > > > > > > It complains that to less pages could be freed. For example
> > > > > > > with kernel 2.6.37:
> > > > > > > 
> > > > > > > Feb 16 00:15:00 shambhala kernel: PM: Creating hibernation
> > > > > > > image: Feb 16 00:15:00 shambhala kernel: PM: Need to copy
> > > > > > > 186577 pages Feb 16 00:15:00 shambhala kernel: PM: Normal
> > > > > > > pages needed: 114411 + 1024, available pages: 112767
> > > > > > > Feb 16 00:15:00 shambhala kernel: PM: Not enough free memory
> > > > > > > Feb 16 00:15:00 shambhala kernel: PM: Error -12 creating
> > > > > > > hibernation image Feb 16 00:15:00 shambhala kernel: Extended
> > > > > > > CMOS year: 2000 Feb 16 00:15:00 shambhala kernel: ACPI:
> > > > > > > Waking up from system sleep state S4
> > > > > > > Feb 16 00:15:00 shambhala kernel: PM: early recover of
> > > > > > > devices complete after 0.376 msecs
> > > > > > 
> > > > > > What's the value in /sys/power/image_size?
> > > > > 
> > > > > shambhala:~> cat /sys/power/image_size
> > > > > 844206080
> > > > > 
> > > > > Should I try with less?
> > > > 
> > > > Yes, please.  Try with 700000000 for example.
> > > 
> > > I replaced dropping by settings image_size to this valua and the
> > > ThinkPad hibernated with KMail open. Thus seems to work, but I will
> > > test a bit further.
> > > 
> > > Where does the higher value previously set come from? Autotuning?
> > 
> > Likely.  The number seems to match at least.
> > 
> > > Is there anything that can be improved with autotuning?
> > 
> > We can lower the ratio of the image size to the total RAM.
> > Alternatively, we can increase SPARE_PAGES.
> > 
> > > If yes, I can file a bug report.
> > 
> > Yes, please.
> 
> Reported-as:
> 
> Bug 30482 - try harder to free enough memory / improve image size 
> autotuning

I attached a patch for you to test to the bug entry.

Thanks,
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/