Patches 1 and 2 are cleanups requested during reviews of prior versions
of this series.
Patch 3 makes sure we never try to flush from within an irq context, and
patch 4 adds a WARN_ON_ONCE() to make sure we catch any violations.
Patches 5 to 8 introduce separate variants of mem_cgroup_flush_stats()
for atomic and non-atomic flushing, and make sure we only flush the
stats atomically when necessary.
Patch 9 is a slightly tangential optimization that limits the work done
by rstat flushing in some scenarios.
v1 -> v2:
- Added more context in patch 4's commit log.
- Added atomic_read() before atomic_xchg() in patch 5 to avoid
needlessly locking the cache line (Shakeel).
- Refactored patch 6: added a common helper, do_flush_stats(), for
mem_cgroup_flush_stats{_atomic}() (Johannes).
- Renamed mem_cgroup_flush_stats_ratelimited() to
mem_cgroup_flush_stats_atomic_ratelimited() in patch 6. It is restored
in patch 7, but this maintains consistency (Johannes).
- Added line break to keep the lock section visually separated in patch
7 (Johannes).
RFC -> v1:
- Dropped patch 1 that attempted to make the global rstat lock a non-irq
lock, will follow up on that separetly (Shakeel).
- Dropped stats_flush_lock entirely, replaced by an atomic (Johannes).
- Renamed cgroup_rstat_flush_irqsafe() to cgroup_rstat_flush_atomic()
instead of removing it (Johannes).
- Added a patch to rename mem_cgroup_flush_stats_delayed() to
mem_cgroup_flush_stats_ratelimited() (Johannes).
- Separate APIs for flushing memcg stats in atomic and non-atomic
contexts instead of a boolean argument (Johannes).
- Added patches 3 & 4 to make sure we never flush from irq context
(Shakeel & Johannes).
Yosry Ahmed (9):
cgroup: rename cgroup_rstat_flush_"irqsafe" to "atomic"
memcg: rename mem_cgroup_flush_stats_"delayed" to "ratelimited"
memcg: do not flush stats in irq context
cgroup: rstat: add WARN_ON_ONCE() if flushing outside task context
memcg: replace stats_flush_lock with an atomic
memcg: sleep during flushing stats in safe contexts
workingset: memcg: sleep when flushing stats in workingset_refault()
vmscan: memcg: sleep when flushing stats during reclaim
memcg: do not modify rstat tree for zero updates
include/linux/cgroup.h | 2 +-
include/linux/memcontrol.h | 9 ++++-
kernel/cgroup/rstat.c | 6 ++-
mm/memcontrol.c | 78 ++++++++++++++++++++++++++++++--------
mm/workingset.c | 5 ++-
5 files changed, 78 insertions(+), 22 deletions(-)
--
2.40.0.348.gf938b09366-goog
