From: Long Li <lonuxli.64@gmail.com>
To: cl@linux.com, penberg@kernel.org, rientjes@google.com,
iamjoonsoo.kim@lge.com, akpm@linux-foundation.org
Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: [PATCH v1] mm:free unused pages in kmalloc_order
Date: Sat, 27 Jun 2020 04:55:07 +0000 [thread overview]
Message-ID: <20200627045507.GA57675@lilong> (raw)
Environment using the slub allocator, 1G memory in my ARM32.
kmalloc(1024, GFP_HIGHUSER) can allocate memory normally,
kmalloc(64*1024, GFP_HIGHUSER) will cause a memory leak, because
alloc_pages returns highmem physical pages, but it cannot be directly
converted into a virtual address and return NULL, the pages has not
been released. Usually driver developers will not use the
GFP_HIGHUSER flag to allocate memory in kmalloc, but I think this
memory leak is not perfect, it is best to be fixed. This is the
first time I have posted a patch, there may be something wrong.
Signed-off-by: Long Li <lonuxli.64@gmail.com>
---
mm/slab_common.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/mm/slab_common.c b/mm/slab_common.c
index a143a8c8f874..d2c53b980ab3 100644
--- a/mm/slab_common.c
+++ b/mm/slab_common.c
@@ -819,8 +819,12 @@ void *kmalloc_order(size_t size, gfp_t flags, unsigned int order)
page = alloc_pages(flags, order);
if (likely(page)) {
ret = page_address(page);
- mod_node_page_state(page_pgdat(page), NR_SLAB_UNRECLAIMABLE_B,
- PAGE_SIZE << order);
+ if (ret)
+ mod_node_page_state(page_pgdat(page),
+ NR_SLAB_UNRECLAIMABLE_B,
+ PAGE_SIZE << order);
+ else
+ __free_pages(page, order);
}
ret = kasan_kmalloc_large(ret, size, flags);
/* As ret might get tagged, call kmemleak hook after KASAN. */
--
2.17.1
next reply other threads:[~2020-06-27 4:55 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-27 4:55 Long Li [this message]
2020-06-29 2:42 ` [PATCH v1] mm:free unused pages in kmalloc_order Matthew Wilcox
2020-06-29 14:49 ` Christopher Lameter
2020-06-29 14:48 ` Christopher Lameter
2020-06-29 14:52 ` Matthew Wilcox
2020-07-01 15:18 ` Christopher Lameter
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