From: David Rientjes <rientjes@google.com>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Dave Kleikamp <shaggy@kernel.org>, Christoph Hellwig <hch@lst.de>,
Sebastian Ott <sebott@linux.vnet.ibm.com>,
Mikulas Patocka <mpatocka@redhat.com>,
Catalin Marinas <catalin.marinas@arm.com>,
linux-kernel@vger.kernel.org, linux-mm@kvack.org,
jfs-discussion@lists.sourceforge.net
Subject: [patch 2/4] mm, mempool: disallow mempools based on slab caches with constructors
Date: Tue, 24 Mar 2015 16:09:10 -0700 (PDT) [thread overview]
Message-ID: <alpine.DEB.2.10.1503241608540.21805@chino.kir.corp.google.com> (raw)
In-Reply-To: <alpine.DEB.2.10.1503241607240.21805@chino.kir.corp.google.com>
All occurrences of mempools based on slab caches with object constructors
have been removed from the tree, so disallow creating them.
We can only dereference mem->ctor in mm/mempool.c without including
mm/slab.h in include/linux/mempool.h. So simply note the restriction,
just like the comment restrictig usage of __GFP_ZERO, and warn on
kernels with CONFIG_DEBUG_VM() if such a mempool is allocated from.
We don't want to incur this check on every element allocation, so use
VM_BUG_ON().
Signed-off-by: David Rientjes <rientjes@google.com>
---
include/linux/mempool.h | 3 ++-
mm/mempool.c | 2 ++
2 files changed, 4 insertions(+), 1 deletion(-)
diff --git a/include/linux/mempool.h b/include/linux/mempool.h
--- a/include/linux/mempool.h
+++ b/include/linux/mempool.h
@@ -36,7 +36,8 @@ extern void mempool_free(void *element, mempool_t *pool);
/*
* A mempool_alloc_t and mempool_free_t that get the memory from
- * a slab that is passed in through pool_data.
+ * a slab cache that is passed in through pool_data.
+ * Note: the slab cache may not have a ctor function.
*/
void *mempool_alloc_slab(gfp_t gfp_mask, void *pool_data);
void mempool_free_slab(void *element, void *pool_data);
diff --git a/mm/mempool.c b/mm/mempool.c
--- a/mm/mempool.c
+++ b/mm/mempool.c
@@ -15,6 +15,7 @@
#include <linux/mempool.h>
#include <linux/blkdev.h>
#include <linux/writeback.h>
+#include "slab.h"
static void add_element(mempool_t *pool, void *element)
{
@@ -332,6 +333,7 @@ EXPORT_SYMBOL(mempool_free);
void *mempool_alloc_slab(gfp_t gfp_mask, void *pool_data)
{
struct kmem_cache *mem = pool_data;
+ VM_BUG_ON(mem->ctor);
return kmem_cache_alloc(mem, gfp_mask);
}
EXPORT_SYMBOL(mempool_alloc_slab);
next prev parent reply other threads:[~2015-03-24 23:09 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-03-24 23:08 [patch 1/4] fs, jfs: remove slab object constructor David Rientjes
2015-03-24 23:09 ` David Rientjes [this message]
2015-03-24 23:09 ` [patch v2 3/4] mm, mempool: poison elements backed by slab allocator David Rientjes
2015-03-24 23:10 ` [patch v2 4/4] mm, mempool: poison elements backed by page allocator David Rientjes
2015-03-25 21:55 ` Andrew Morton
2015-03-26 16:07 ` Andrey Ryabinin
2015-03-26 20:38 ` Andrey Ryabinin
2015-03-26 22:50 ` David Rientjes
2015-03-30 8:53 ` Andrey Ryabinin
2015-03-31 11:33 ` Andrey Ryabinin
2015-04-03 1:04 ` David Rientjes
2015-04-03 1:07 ` [patch -mm] mm, mempool: poison elements backed by page allocator fix fix David Rientjes
2015-03-24 23:41 ` [patch 1/4] fs, jfs: remove slab object constructor Dave Kleikamp
2015-03-26 2:18 ` Mikulas Patocka
2015-03-26 2:37 ` David Rientjes
2015-03-26 7:28 ` Christoph Hellwig
2015-03-26 14:57 ` Dave Kleikamp
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