performance regressions in the recent rewrite
of the SCHED_MM_CID management code:
- Fix livelock triggered by BPF CI testing
- Fix hard lockup on weakly ordered systems
- Simplify the dropping of CIDs in the exit path
by removing an unintended transition phase.
- Fix performance/scalability regression on a
thread-pool benchmark by optimizing transitional
CIDs when scheduling out.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
-----BEGIN PGP SIGNATURE-----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=/PkF
-----END PGP SIGNATURE-----
Merge tag 'sched-urgent-2026-02-07' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler fixes from Ingo Molnar:
"Miscellaneous MMCID fixes to address bugs and performance regressions
in the recent rewrite of the SCHED_MM_CID management code:
- Fix livelock triggered by BPF CI testing
- Fix hard lockup on weakly ordered systems
- Simplify the dropping of CIDs in the exit path by removing an
unintended transition phase
- Fix performance/scalability regression on a thread-pool benchmark
by optimizing transitional CIDs when scheduling out"
* tag 'sched-urgent-2026-02-07' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched/mmcid: Optimize transitional CIDs when scheduling out
sched/mmcid: Drop per CPU CID immediately when switching to per task mode
sched/mmcid: Protect transition on weakly ordered systems
sched/mmcid: Prevent live lock on task to CPU mode transition
dda5df9823