* Greg Thelen <gthelen@xxxxxxxxxx> [2010-10-03 23:57:55]: > This patch set provides the ability for each cgroup to have independent dirty > page limits. > > Limiting dirty memory is like fixing the max amount of dirty (hard to reclaim) > page cache used by a cgroup. So, in case of multiple cgroup writers, they will > not be able to consume more than their designated share of dirty pages and will > be forced to perform write-out if they cross that limit. > > These patches were developed and tested on mmotm 2010-09-28-16-13. The patches > are based on a series proposed by Andrea Righi in Mar 2010. > > Overview: > - Add page_cgroup flags to record when pages are dirty, in writeback, or nfs > unstable. > - Extend mem_cgroup to record the total number of pages in each of the > interesting dirty states (dirty, writeback, unstable_nfs). > - Add dirty parameters similar to the system-wide /proc/sys/vm/dirty_* > limits to mem_cgroup. The mem_cgroup dirty parameters are accessible > via cgroupfs control files. > - Consider both system and per-memcg dirty limits in page writeback when > deciding to queue background writeback or block for foreground writeback. > > Known shortcomings: > - When a cgroup dirty limit is exceeded, then bdi writeback is employed to > writeback dirty inodes. Bdi writeback considers inodes from any cgroup, not > just inodes contributing dirty pages to the cgroup exceeding its limit. I suspect this means that we'll need a bdi controller in the I/O controller spectrum or make writeback cgroup aware. > > Performance measurements: > - kernel builds are unaffected unless run with a small dirty limit. > - all data collected with CONFIG_CGROUP_MEM_RES_CTLR=y. > - dd has three data points (in secs) for three data sizes (100M, 200M, and 1G). > As expected, dd slows when it exceed its cgroup dirty limit. > > kernel_build dd > mmotm 2:37 0.18, 0.38, 1.65 > root_memcg > > mmotm 2:37 0.18, 0.35, 1.66 > non-root_memcg > > mmotm+patches 2:37 0.18, 0.35, 1.68 > root_memcg > > mmotm+patches 2:37 0.19, 0.35, 1.69 > non-root_memcg > > mmotm+patches 2:37 0.19, 2.34, 22.82 > non-root_memcg > 150 MiB memcg dirty limit > > mmotm+patches 3:58 1.71, 3.38, 17.33 > non-root_memcg > 1 MiB memcg dirty limit > > Greg Thelen (10): > memcg: add page_cgroup flags for dirty page tracking > memcg: document cgroup dirty memory interfaces > memcg: create extensible page stat update routines > memcg: disable local interrupts in lock_page_cgroup() > memcg: add dirty page accounting infrastructure > memcg: add kernel calls for memcg dirty page stats > memcg: add dirty limits to mem_cgroup > memcg: add cgroupfs interface to memcg dirty limits > writeback: make determine_dirtyable_memory() static. > memcg: check memcg dirty limits in page writeback > > Documentation/cgroups/memory.txt | 37 ++++ > fs/nfs/write.c | 4 + > include/linux/memcontrol.h | 78 +++++++- > include/linux/page_cgroup.h | 31 +++- > include/linux/writeback.h | 2 - > mm/filemap.c | 1 + > mm/memcontrol.c | 426 ++++++++++++++++++++++++++++++++++---- > mm/page-writeback.c | 211 ++++++++++++------- > mm/rmap.c | 4 +- > mm/truncate.c | 1 + > 10 files changed, 672 insertions(+), 123 deletions(-) > > -- > 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/ . > Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a> > -- Three Cheers, Balbir -- 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/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>