This series attempts to address shortages in today's approach for memcg stats flushing, namely occasionally stale or expensive stat reads. The series does so by changing the threshold that we use to decide whether to trigger a flush to be per memcg instead of global (patch 3), and then changing flushing to be per memcg (i.e. subtree flushes) instead of global (patch 5). Patch 3 & 5 are the core of the series, and they include more details and testing results. The rest are either cleanups or prep work. This series replaces the "memcg: more sophisticated stats flushing" series [1], which also replaces another series, in a long list of attempts to improve memcg stats flushing. It is not a new version of the same patchset as it is a completely different approach. This is based on collected feedback from discussions on lkml in all previous attempts. Hopefully, this is the final attempt. [1]https://lore.kernel.org/lkml/20230913073846.1528938-1-yosryahmed@xxxxxxxxxx/ v1 -> v2: - Fixed compilation error reported by the kernel robot in patch 4, also added a missing rcu_read_unlock(). - More testing results in the commit message of patch 3. Yosry Ahmed (5): mm: memcg: change flush_next_time to flush_last_time mm: memcg: move vmstats structs definition above flushing code mm: memcg: make stats flushing threshold per-memcg mm: workingset: move the stats flush into workingset_test_recent() mm: memcg: restore subtree stats flushing include/linux/memcontrol.h | 8 +- mm/memcontrol.c | 269 +++++++++++++++++++++---------------- mm/vmscan.c | 2 +- mm/workingset.c | 42 ++++-- 4 files changed, 185 insertions(+), 136 deletions(-) -- 2.42.0.609.gbb76f46606-goog
