[PATCH v2 0/4] proc: improve root readdir latency with many threads

From: Brian Foster
Date: Mon Jul 11 2022 - 09:52:58 EST

Hi all,

Here's v2 of the /proc readdir optimization patches. See v1 for the full
introductary cover letter.

The refactoring in v2 adds a bit more to the idr code, but it remains
trivial with respect to eventual xarray (tag -> mark) conversion. On
that topic, I'm still looking for some feedback in the v1 thread [1] on
the prospective approach...


[1] https://lore.kernel.org/linux-fsdevel/YrykXim1t71TgdYg@bfoster/

- Clean up idr helpers to be more generic.
- Use ->idr_base properly.
- Lift tgid iteration helper into pid.c to abstract tag logic from
v1: https://lore.kernel.org/linux-fsdevel/20220614180949.102914-1-bfoster@xxxxxxxxxx/

Brian Foster (4):
radix-tree: propagate all tags in idr tree
idr: support optional id tagging
pid: tag pids associated with group leader tasks
procfs: use efficient tgid pid search on root readdir

fs/proc/base.c | 17 +----------------
include/linux/idr.h | 26 ++++++++++++++++++++++++++
include/linux/pid.h | 3 ++-
kernel/fork.c | 2 +-
kernel/pid.c | 40 +++++++++++++++++++++++++++++++++++++++-
lib/radix-tree.c | 26 +++++++++++++++-----------
6 files changed, 84 insertions(+), 30 deletions(-)