[0/2] memcg: tracepoint for flushing stats

Message

JP Kobryn Oct. 25, 2024, 12:25 a.m. UTC

This tracepoint gives visibility on how often the flushing of memcg stats
occurs, along with the reason for the flush. It can help with understanding
how readers are affected by having to perform the flush; the event captures
the info on whether the flush was skipped or not. The information collected
could help in determining the effectiveness of the background work where
the flush is scheduled periodically. Paired with the recently added
tracepoints for tracing rstat updates, it can also help show correlation
where stats exceed thresholds frequently.

Note there is one reason called "zswap" that was included to distinguish
one special case where a zswap function makes a direct call to
do_flush_stats().

JP Kobryn (2):
  add memcg flush tracepoint event
  use memcg flush tracepoint

 include/trace/events/memcg.h | 56 ++++++++++++++++++++++++++++++++++++
 mm/memcontrol.c              |  7 ++++-
 2 files changed, 62 insertions(+), 1 deletion(-)