On Wed, Jun 01, 2011 at 09:05:18PM -0700, Ying Han wrote: > On Wed, Jun 1, 2011 at 4:52 PM, Hiroyuki Kamezawa > <kamezawa.hiroyuki@xxxxxxxxx> wrote: > > 2011/6/1 Johannes Weiner <hannes@xxxxxxxxxxx>: > >> Hi, > >> > >> this is the second version of the memcg naturalization series. The > >> notable changes since the first submission are: > >> > >> o the hierarchy walk is now intermittent and will abort and > >> remember the last scanned child after sc->nr_to_reclaim pages > >> have been reclaimed during the walk in one zone (Rik) > >> > >> o the global lru lists are never scanned when memcg is enabled > >> after #2 'memcg-aware global reclaim', which makes this patch > >> self-sufficient and complete without requiring the per-memcg lru > >> lists to be exclusive (Michal) > >> > >> o renamed sc->memcg and sc->current_memcg to sc->target_mem_cgroup > >> and sc->mem_cgroup and fixed their documentation, I hope this is > >> better understandable now (Rik) > >> > >> o the reclaim statistic counters have been renamed. there is no > >> more distinction between 'pgfree' and 'pgsteal', it is now > >> 'pgreclaim' in both cases; 'kswapd' has been replaced by > >> 'background' > >> > >> o fixed a nasty crash in the hierarchical soft limit check that > >> happened during global reclaim in memcgs that are hierarchical > >> but have no hierarchical parents themselves > >> > >> o properly implemented the memcg-aware unevictable page rescue > >> scanner, there were several blatant bugs in there > >> > >> o documentation on new public interfaces > >> > >> Thanks for your input on the first version. > >> > >> I ran microbenchmarks (sparse file catting, essentially) to stress > >> reclaim and LRU operations. There is no measurable overhead for > >> !CONFIG_MEMCG, memcg disabled during boot, memcg enabled but no > >> configured groups, and hard limit reclaim. > >> > >> I also ran single-threaded kernbenchs in four unlimited memcgs in > >> parallel, contained in a hard-limited hierarchical parent that put > >> constant pressure on the workload. There is no measurable difference > >> in runtime, the pgpgin/pgpgout counters, and fairness among memcgs in > >> this test compared to an unpatched kernel. Needs more evaluation, > >> especially with a higher number of memcgs. > >> > >> The soft limit changes are also proven to work in so far that it is > >> possible to prioritize between children in a hierarchy under pressure > >> and that runtime differences corresponded directly to the soft limit > >> settings in the previously described kernbench setup with staggered > >> soft limits on the groups, but this needs quantification. > >> > >> Based on v2.6.39. > >> > > > > Hmm, I welcome and will review this patches but.....some points I want to say. > > > > 1. No more conflict with Ying's work ? > > Could you explain what she has and what you don't in this v2 ? > > If Ying's one has something good to be merged to your set, please > > include it. > > My patch I sent out last time was doing rework of soft_limit reclaim. > It convert the RB-tree based to > a linked list round-robin fashion of all memcgs across their soft > limit per-zone. > > I will apply this patch and try to test it. After that i will get > better idea whether or not it is being covered here. Thanks!! > > 4. This work can be splitted into some small works. > > a) fix for current code and clean ups > > > a') statistics > > > b) soft limit rework > > > c) change global reclaim > > My last patchset starts with a patch reverting the RB-tree > implementation of the soft_limit > reclaim, and then the new round-robin implementation comes on the > following patches. > > I like the ordering here, and that is consistent w/ the plan we > discussed earlier in LSF. Changing > the global reclaim would be the last step when the changes before that > have been well understood > and tested. > > Sorry If that is how it is done here. I will read through the patchset. It's not. The way I implemented soft limits depends on global reclaim performing hierarchical reclaim. I don't see how I can reverse the order with this dependency. -- 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 internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>