The zsmalloc has used bit_spin_lock to minimize space overhead since it's zpage granularity lock. However, it causes zsmalloc non-working under PREEMPT_RT as well as adding too much complication. This patchset tries to replace the bit_spin_lock with per-pool rwlock. It also removes unnecessary zspage isolation logic from class, which was the other part too much complication added into zsmalloc. Last patch changes the get_cpu_var to local_lock to make it work in PREEMPT_RT. Mike Galbraith (1): zsmalloc: replace get_cpu_var with local_lock Minchan Kim (8): zsmalloc: introduce some helper functions zsmalloc: rename zs_stat_type to class_stat_type zsmalloc: decouple class actions from zspage works zsmalloc: introduce obj_allocated zsmalloc: move huge compressed obj from page to zspage zsmalloc: remove zspage isolation for migration locking/rwlocks: introduce write_lock_nested zsmalloc: replace per zpage lock with pool->migrate_lock include/linux/rwlock.h | 6 + include/linux/rwlock_api_smp.h | 9 + include/linux/rwlock_rt.h | 6 + include/linux/spinlock_api_up.h | 1 + kernel/locking/spinlock.c | 6 + kernel/locking/spinlock_rt.c | 12 + mm/zsmalloc.c | 529 ++++++++++++-------------------- 7 files changed, 228 insertions(+), 341 deletions(-) -- * from v1 - https://lore.kernel.org/linux-mm/20211110185433.1981097-1-minchan@xxxxxxxxxx/ * add write_lock_nested for rwlock * change fromline to "Mike Galbraith" - bigeasy@ 2.34.0.rc1.387.gb447b232ab-goog
