On Wed, Nov 24, 2010 at 3:47 AM, KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx> wrote: > On Mon, 22 Nov 2010 19:59:41 +0300 > Evgeniy Ivanov <lolkaantimat@xxxxxxxxx> wrote: > >> Hello, >> > Hi, > >> I have following cgroup hierarchy: >> >> Root >> / | >> A B >> >> A and B have memory limits set so that it's 100% of limit set in Root. >> I want to add C to root: >> >> Root >> / | \ >> A B C >> >> What is correct way to shrink limits for A and B? When they use all >> allowed memory and I try to write to their limit files I get error. > > What kinds of error ? Do you have swap ? What is the kerenel version ? Kernel is 2.6.31-5 from SLES-SP1 (my build, but without extra patches). I have 2 Gb swap and just 40 Mb used. Machine has 3 Gb RAM and no load (neither mem or CPU). Error is "-bash: echo: write error: Device or resource busy", when I write to memory.limit_in_bytes. > It's designed to allow "shrink at once" but that means release memory > and do forced-writeback. To release memory, it may have to write back > to swap. If tasks in "A" and "B" are too busy and tocuhes tons of memory > while shrinking, it may fail. Well, in test I have a process which uses 30M of memory and in loop dirties all pages (just single byte) then sleeps 5 seconds before next iteration. > It may be a regression. Kernel version is important. > > Could you show memory.stat file when you shrink "A" and "B" ? > And what happnes > # sync > # sync > # sync > # reduce memory A > # reduce memory B Sync doesn't help. Here is log just for memory.stat for group I tried to shrink: ivanoe:/cgroups/root# cat C/memory.stat cache 0 rss 90222592 mapped_file 0 pgpgin 1212770 pgpgout 1190743 inactive_anon 45338624 active_anon 44883968 inactive_file 0 active_file 0 unevictable 0 hierarchical_memory_limit 94371840 hierarchical_memsw_limit 9223372036854775807 total_cache 0 total_rss 90222592 total_mapped_file 0 total_pgpgin 1212770 total_pgpgout 1190743 total_inactive_anon 45338624 total_active_anon 44883968 total_inactive_file 0 total_active_file 0 total_unevictable 0 ivanoe:/cgroups/root# echo 30M > C/memory.limit_in_bytes -bash: echo: write error: Device or resource busy ivanoe:/cgroups/root# echo 30M > C/memory.limit_in_bytes -bash: echo: write error: Device or resource busy ivanoe:/cgroups/root# echo 30M > C/memory.limit_in_bytes -bash: echo: write error: Device or resource busy ivanoe:/cgroups/root# echo 30M > C/memory.limit_in_bytes ivanoe:/cgroups/root# cat memory.limit_in_bytes 125829120 ivanoe:/cgroups/root# cat B/memory.limit_in_bytes 62914560 ivanoe:/cgroups/root# cat A/memory.limit_in_bytes 20971520 -- Evgeniy Ivanov -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom policy in Canada: sign http://dissolvethecrtc.ca/ Don't email: <a href