Re: 2.6.19-rc1-mm1+ memory problem

[Andrew Morton <akpm@osdl.org>]

On Sat, 25 Nov 2006 02:07:43 +0300
Michael Raskin <a1d23ab4@mail.ru> wrote:

> Michael Raskin wrote:
> > Also I have uploaded contents of /proc/page_owner after loosing more 
> > than 100M. (220M used, 29M - on page_owner, lessthan 50M - for 
> > processes). 
> 
> Top 3 entries:
> 
> 89361 times:
> Page allocated via order 0, mask 0x280d2
> [0xc0159f31] __handle_mm_fault+1809
> [0xc011318a] do_page_fault+314
> [0xc04111c4] error_code+116
> Can be anything. But if I understand anything, this memory is used 
> because someone has requested a page that is swapped out. So the memory 
> must be used, but not reflected in meminfo, and not by a process?
> 
> 
> 35560 times:
> Page allocated via order 0, mask 0x201d2
> [0xc0152ec2] __do_page_cache_readahead+450
> [0xc015309a] do_page_cache_readahead+74
> [0xc014d7b5] filemap_nopage+325
> [0xc0159919] __handle_mm_fault+249
> [0xc011318a] do_page_fault+314
> [0xc04111c4] error_code+116
> - is reflected in cache usage statistics, I guess..
> 
> 6185 times:
> Page allocated via order 0, mask 0x200d2
> [0xc014e069] generic_file_buffered_write+329
> [0xc014e814] __generic_file_aio_write_nolock+612
> [0xc014eb85] generic_file_aio_write+85
> [0xc01b26ff] ext3_file_write+63
> [0xc016b23c] do_sync_write+204
> [0xc016b9a7] vfs_write+167
> [0xc016c2a7] sys_write+71
> [0xc010303a] sysenter_past_esp+95
> - negligible, really..

What you should do is to cause the system to free as many pages as possible
before looking ad /proc/page_owner.  For example, build `usemem' from
http://www.zip.com.au/~akpm/linux/patches/stuff/ext3-tools.tar.gz, run

	usemem -m N  (where N is the number of megabytes which the machine has)

a couple of times.  Then check /proc/meminfo, and look to see which pages
are left over in /proc/page_owner.

Thanks.