[patch] mm/slub: Replace do_slab_free() local_lock_irqsave/restore() calls in PREEMPT_RT scope

From: Mike Galbraith
Date: Fri Jul 09 2021 - 01:20:57 EST



IRQ affecting local lock operations are intended for dual RT/!RT scope,
only affect IRQs in !RT scope. Replace misplaced do_slab_free() calls
with plain local_lock()/local_unlock(). Purely cosmetic.

Signed-off-by: Mike Galbraith <efault@xxxxxx>
---
mm/slub.c | 7 +++----
1 file changed, 3 insertions(+), 4 deletions(-)

--- a/mm/slub.c
+++ b/mm/slub.c
@@ -3362,13 +3362,12 @@ static __always_inline void do_slab_free
* we need to take the local_lock. We shouldn't simply defer to
* __slab_free() as that wouldn't use the cpu freelist at all.
*/
- unsigned long flags;
void **freelist;

- local_lock_irqsave(&s->cpu_slab->lock, flags);
+ local_lock(&s->cpu_slab->lock);
c = this_cpu_ptr(s->cpu_slab);
if (unlikely(page != c->page)) {
- local_unlock_irqrestore(&s->cpu_slab->lock, flags);
+ local_unlock(&s->cpu_slab->lock);
goto redo;
}
tid = c->tid;
@@ -3378,7 +3377,7 @@ static __always_inline void do_slab_free
c->freelist = head;
c->tid = next_tid(tid);

- local_unlock_irqrestore(&s->cpu_slab->lock, flags);
+ local_unlock(&s->cpu_slab->lock);
#endif
stat(s, FREE_FASTPATH);
} else