Messages in this thread | | | Date | Mon, 17 Sep 2007 16:32:57 +0200 | From | Peter Zijlstra <> | Subject | Re: VM/VFS bug with large amount of memory and file systems? |
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On Mon, 17 Sep 2007 15:04:05 +0100 Anton Altaparmakov <aia21@cam.ac.uk> wrote:
> They files > are attached this time rather than inlined so people don't complain > about line wrapping! (No doubt people will not complain about them > being attached! )-:)
I switched mailer after I learnt about flowed stuffs. Still, appreciated.
> If I read it correctly it appears all of low memory is eaten up by > buffer_heads. > > <quote> > # name <active_objs> <num_objs> <objsize> <objperslab> > <pagesperslab> > : tunables <limit> <batchcount> <sharedfactor> : slabdata > <active_slabs> <num_s > labs> <sharedavail> > buffer_head 12569528 12569535 56 67 1 : tunables > 120 60 8 : > slabdata 187605 187605 0 > </quote> > > That is 671MiB of low memory in buffer_heads. > > But why is the kernel not reclaiming them by getting rid of the page > cache pages they are attached to or even leaving the pages around but > killing their buffers?
Well, you see, you have this very odd configuration where:
11GB highmem 1GB normal
pagecache pages go into highmem buggerheads go into normal
I'm guessing there is no pressure at all on zone_highmem so the kernel will not try to reclaim pagecache. And because the pagecache pages are happily sitting there, the buggerheads are pinned and do not get reclaimed. - 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/
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