Messages in this thread | | | Subject | Re: [RFC][PATCH 4/5] PM/Hibernate: Rework shrinking of memory | From | Nigel Cunningham <> | Date | Fri, 08 May 2009 06:53:14 +1000 |
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Hi.
On Thu, 2009-05-07 at 22:00 +0200, Rafael J. Wysocki wrote: > On Thursday 07 May 2009, Rafael J. Wysocki wrote: > > On Thursday 07 May 2009, Nigel Cunningham wrote: > > > Hi. > > > > Hi, > > > > > On Thu, 2009-05-07 at 00:44 +0200, Rafael J. Wysocki wrote: > > > > From: Rafael J. Wysocki <rjw@sisk.pl> > > > > > > > > Rework swsusp_shrink_memory() so that it calls shrink_all_memory() > > > > just once to make some room for the image and then allocates memory > > > > to apply more pressure to the memory management subsystem, if > > > > necessary. > > > > > > > > Unfortunately, we don't seem to be able to drop shrink_all_memory() > > > > entirely just yet, because that would lead to huge performance > > > > regressions in some test cases. > > > > > > I know it doesn't fit with your current way of doing things, but have > > > you considered trying larger order allocations as a means of getting > > > memory freed? > > > > Actually, I was thinking about that. What's your experience with this > > approach? > > > > > I have code in tuxonice_prepare_image.c (look for extra_pages_allocated) that > > > might be helpful for this purpose. > > > > OK, thanks. I'll have a look at it. > > I have tried it, but the results are even worse than with 0-order allocations > only. > > So far, I have got the best results with shrink_all_memory() called once and > followed by allocating as much memory as we want to be free using 0-order > allocations. Like in this patch. :-)
Hmm. That's surprising. It would be interesting to look at what's going on. Unfortunately, I just don't have the time at the moment to help.
Regards,
Nigel
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