From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from szxga01-in.huawei.com ([119.145.14.64]) by merlin.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1WBxTH-0005Pr-IN for linux-mtd@lists.infradead.org; Sat, 08 Feb 2014 02:16:45 +0000 Message-ID: <52F5934B.4000101@huawei.com> Date: Sat, 8 Feb 2014 10:15:39 +0800 From: Li Zefan MIME-Version: 1.0 To: Andrew Morton Subject: [PATCH 2/3] jffs2: avoid soft-lockup in jffs2_reserve_space_gc() References: <52F592F2.6010008@huawei.com> In-Reply-To: <52F592F2.6010008@huawei.com> Content-Type: text/plain; charset="GB2312" Content-Transfer-Encoding: 7bit Cc: linux-mtd@lists.infradead.org, dwmw2@infradead.org, LKML List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , We triggered soft-lockup under stress test on 2.6.34 kernel. BUG: soft lockup - CPU#1 stuck for 60009ms! [lockf2.test:14488] ... [] (jffs2_do_reserve_space+0x420/0x440 [jffs2]) [] (jffs2_reserve_space_gc+0x34/0x78 [jffs2]) [] (jffs2_garbage_collect_dnode.isra.3+0x264/0x478 [jffs2]) [] (jffs2_garbage_collect_pass+0x9c0/0xe4c [jffs2]) [] (jffs2_reserve_space+0x104/0x2a8 [jffs2]) [] (jffs2_write_inode_range+0x5c/0x4d4 [jffs2]) [] (jffs2_write_end+0x198/0x2c0 [jffs2]) [] (generic_file_buffered_write+0x158/0x200) [] (__generic_file_aio_write+0x3a4/0x414) [] (generic_file_aio_write+0x5c/0xbc) [] (do_sync_write+0x98/0xd4) [] (vfs_write+0xa8/0x150) [] (sys_write+0x3c/0xc0)] Fix this by adding a cond_resched() in the while loop. Cc: Signed-off-by: Li Zefan --- fs/jffs2/nodemgmt.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/fs/jffs2/nodemgmt.c b/fs/jffs2/nodemgmt.c index 0331072..fb30161 100644 --- a/fs/jffs2/nodemgmt.c +++ b/fs/jffs2/nodemgmt.c @@ -216,15 +216,20 @@ int jffs2_reserve_space_gc(struct jffs2_sb_info *c, uint32_t minsize, jffs2_dbg(1, "%s(): Requested 0x%x bytes\n", __func__, minsize); - spin_lock(&c->erase_completion_lock); - while(ret == -EAGAIN) { + while (true) { + spin_lock(&c->erase_completion_lock); ret = jffs2_do_reserve_space(c, minsize, len, sumsize); if (ret) { jffs2_dbg(1, "%s(): looping, ret is %d\n", __func__, ret); } + spin_unlock(&c->erase_completion_lock); + + if (ret == -EAGAIN) + cond_resched(); + else + break; } - spin_unlock(&c->erase_completion_lock); if (!ret) ret = jffs2_prealloc_raw_node_refs(c, c->nextblock, 1); -- 1.8.0.2