[merged] mm-slub-make-locking-in-deactivate_slab-irq-safe.patch removed from -mm tree

[akpm@linux-foundation.org]

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@suse.cz>
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@suse.cz
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Jann Horn <jannh@google.com>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Qian Cai <quic_qiancai@quicinc.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 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@suse.cz are