From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail143.messagelabs.com (mail143.messagelabs.com [216.82.254.35]) by kanga.kvack.org (Postfix) with SMTP id DFA448D003B for ; Mon, 28 Mar 2011 01:19:26 -0400 (EDT) From: Bob Liu Subject: [PATCH] ramfs: fix memleak on no-mmu arch Date: Mon, 28 Mar 2011 13:32:35 +0800 Message-ID: <1301290355-8980-1-git-send-email-lliubbo@gmail.com> MIME-Version: 1.0 Content-Type: text/plain Sender: owner-linux-mm@kvack.org List-ID: To: akpm@linux-foundation.org Cc: linux-mm@kvack.org, hughd@google.com, viro@zeniv.linux.org.uk, hch@lst.de, npiggin@kernel.dk, tj@kernel.org, dhowells@redhat.com, lethal@linux-sh.org, magnus.damm@gmail.com, Bob Liu On no-mmu arch, there is a memleak duirng shmem test. The cause of this memleak is ramfs_nommu_expand_for_mapping() added page refcount to 2 which makes iput() can't free that pages. The simple test file is like this: int main(void) { int i; key_t k = ftok("/etc", 42); for ( i=0; i<100; ++i) { int id = shmget(k, 10000, 0644|IPC_CREAT); if (id == -1) { printf("shmget error\n"); } if(shmctl(id, IPC_RMID, NULL ) == -1) { printf("shm rm error\n"); return -1; } } printf("run ok...\n"); return 0; } And the result: root:/> free total used free shared buffers Mem: 60320 16644 43676 0 0 -/+ buffers: 16644 43676 root:/> shmem run ok... root:/> free total used free shared buffers Mem: 60320 17912 42408 0 0 -/+ buffers: 17912 42408 root:/> shmem run ok... root:/> free total used free shared buffers Mem: 60320 19096 41224 0 0 -/+ buffers: 19096 41224 root:/> shmem run ok... root:/> free total used free shared buffers Mem: 60320 20296 40024 0 0 -/+ buffers: 20296 40024 root:/> shmem run ok... root:/> free total used free shared buffers Mem: 60320 21496 38824 0 0 -/+ buffers: 21496 38824 root:/> shmem run ok... root:/> free total used free shared buffers Mem: 60320 22692 37628 0 0 -/+ buffers: 22692 37628 root:/> After this patch the test result is:(no memleak anymore) root:/> root:/> free total used free shared buffers Mem: 60320 16580 43740 0 0 -/+ buffers: 16580 43740 root:/> shmem run ok... root:/> free total used free shared buffers Mem: 60320 16668 43652 0 0 -/+ buffers: 16668 43652 root:/> shmem run ok... root:/> free total used free shared buffers Mem: 60320 16668 43652 0 0 -/+ buffers: 16668 43652 root:/> shmem run ok... root:/> free total used free shared buffers Mem: 60320 16668 43652 0 0 -/+ buffers: 16668 43652 root:/> shmem run ok... root:/> free total used free shared buffers Mem: 60320 16668 43652 0 0 -/+ buffers: 16668 43652 root:/> shmem run ok... root:/> free total used free shared buffers Mem: 60320 16668 43652 0 0 -/+ buffers: 16668 43652 root:/> Signed-off-by: Bob Liu --- fs/ramfs/file-nommu.c | 1 + 1 files changed, 1 insertions(+), 0 deletions(-) diff --git a/fs/ramfs/file-nommu.c b/fs/ramfs/file-nommu.c index 9eead2c..fbb0b47 100644 --- a/fs/ramfs/file-nommu.c +++ b/fs/ramfs/file-nommu.c @@ -112,6 +112,7 @@ int ramfs_nommu_expand_for_mapping(struct inode *inode, size_t newsize) SetPageDirty(page); unlock_page(page); + put_page(page); } return 0; -- 1.6.3.3 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org