The patch titled
Subject: mm, slub: make locking in deactivate_slab() irq-safe
has been removed from the -mm tree. Its filename was
mm-slub-make-locking-in-deactivate_slab-irq-safe.patch
This patch was dropped because it was merged into mainline or a subsystem tree
------------------------------------------------------
From: Vlastimil Babka <vbabka@xxxxxxx>
Subject: mm, slub: make locking in deactivate_slab() irq-safe
deactivate_slab() now no longer touches the kmem_cache_cpu structure, so
it will be possible to call it with irqs enabled. Just convert the
spin_lock calls to their irq saving/restoring variants to make it
irq-safe.
Note we now have to use cmpxchg_double_slab() for irq-safe slab_lock(),
because in some situations we don't take the list_lock, which would
disable irqs.
Link: https://lkml.kernel.org/r/20210904105003.11688-20-vbabka@xxxxxxx
Signed-off-by: Vlastimil Babka <vbabka@xxxxxxx>
Cc: Christoph Lameter <cl@xxxxxxxxx>
Cc: David Rientjes <rientjes@xxxxxxxxxx>
Cc: Jann Horn <jannh@xxxxxxxxxx>
Cc: Jesper Dangaard Brouer <brouer@xxxxxxxxxx>
Cc: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
Cc: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx>
Cc: Mike Galbraith <efault@xxxxxx>
Cc: Pekka Enberg <penberg@xxxxxxxxxx>
Cc: Qian Cai <quic_qiancai@xxxxxxxxxxx>
Cc: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/slub.c | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)
--- a/mm/slub.c~mm-slub-make-locking-in-deactivate_slab-irq-safe
+++ a/mm/slub.c
@@ -2223,6 +2223,7 @@ static void deactivate_slab(struct kmem_
enum slab_modes l = M_NONE, m = M_NONE;
void *nextfree, *freelist_iter, *freelist_tail;
int tail = DEACTIVATE_TO_HEAD;
+ unsigned long flags = 0;
struct page new;
struct page old;
@@ -2298,7 +2299,7 @@ redo:
* that acquire_slab() will see a slab page that
* is frozen
*/
- spin_lock(&n->list_lock);
+ spin_lock_irqsave(&n->list_lock, flags);
}
} else {
m = M_FULL;
@@ -2309,7 +2310,7 @@ redo:
* slabs from diagnostic functions will not see
* any frozen slabs.
*/
- spin_lock(&n->list_lock);
+ spin_lock_irqsave(&n->list_lock, flags);
}
}
@@ -2326,14 +2327,14 @@ redo:
}
l = m;
- if (!__cmpxchg_double_slab(s, page,
+ if (!cmpxchg_double_slab(s, page,
old.freelist, old.counters,
new.freelist, new.counters,
"unfreezing slab"))
goto redo;
if (lock)
- spin_unlock(&n->list_lock);
+ spin_unlock_irqrestore(&n->list_lock, flags);
if (m == M_PARTIAL)
stat(s, tail);
_
Patches currently in -mm which might be from vbabka@xxxxxxx are
