[PATCH v2 0/7] Optimize cgroup context switch

From: Ian Rogers
Date: Wed Jul 24 2019 - 18:38:23 EST

Organize per-CPU perf event groups by cgroup then by group/insertion index.
To support cgroup hierarchies, a set of iterators is needed in
visit_groups_merge. To make this unbounded, use a per-CPU allocated
buffer. To make the set of iterators fast, use a min-heap ordered by
the group index.

These patches include a caching algorithm that avoids a search for the
first event in a group by Kan Liang <kan.liang@xxxxxxxxxxxxxxx> and the
set of patches as a whole have benefitted from conversation with him.

Version 2 of these patches addresses review comments and fixes bugs
found by Jiri Olsa and Peter Zijlstra.

Ian Rogers (7):
perf: propagate perf_install_in_context errors up
perf/cgroup: order events in RB tree by cgroup id
perf: order iterators for visit_groups_merge into a min-heap
perf: avoid a bounded set of visit_groups_merge iterators
perf: cache perf_event_groups_first for cgroups
perf: avoid double checking CPU and cgroup
perf: rename visit_groups_merge to ctx_groups_sched_in

include/linux/perf_event.h | 8 +
kernel/events/core.c | 511 +++++++++++++++++++++++++++++--------
2 files changed, 414 insertions(+), 105 deletions(-)