+ linux-mtd Hi Li,
On Wed, Feb 12, 2014 at 12:44:56PM -0800, Andrew Morton wrote: > From: Li Zefan <[email protected]> > Subject: jffs2: avoid soft-lockup in jffs2_reserve_space_gc() > > We triggered soft-lockup under stress test on 2.6.34 kernel. > > BUG: soft lockup - CPU#1 stuck for 60009ms! [lockf2.test:14488] > ... > [<bf09a4d4>] (jffs2_do_reserve_space+0x420/0x440 [jffs2]) > [<bf09a528>] (jffs2_reserve_space_gc+0x34/0x78 [jffs2]) > [<bf0a1350>] (jffs2_garbage_collect_dnode.isra.3+0x264/0x478 [jffs2]) > [<bf0a2078>] (jffs2_garbage_collect_pass+0x9c0/0xe4c [jffs2]) > [<bf09a670>] (jffs2_reserve_space+0x104/0x2a8 [jffs2]) > [<bf09dc48>] (jffs2_write_inode_range+0x5c/0x4d4 [jffs2]) > [<bf097d8c>] (jffs2_write_end+0x198/0x2c0 [jffs2]) > [<c00e00a4>] (generic_file_buffered_write+0x158/0x200) > [<c00e14f4>] (__generic_file_aio_write+0x3a4/0x414) > [<c00e15c0>] (generic_file_aio_write+0x5c/0xbc) > [<c012334c>] (do_sync_write+0x98/0xd4) > [<c0123a84>] (vfs_write+0xa8/0x150) > [<c0123d74>] (sys_write+0x3c/0xc0)] > > Fix this by adding a cond_resched() in the while loop. This patch looks good. > [[email protected]: don't initialize `ret'] > Signed-off-by: Li Zefan <[email protected]> > Cc: David Woodhouse <[email protected]> > Cc: Brian Norris <[email protected]> > Cc: Artem Bityutskiy <[email protected]> > Cc: <[email protected]> > Signed-off-by: Andrew Morton <[email protected]> > --- > > fs/jffs2/nodemgmt.c | 13 +++++++++---- > 1 file changed, 9 insertions(+), 4 deletions(-) > > diff -puN > fs/jffs2/nodemgmt.c~jffs2-avoid-soft-lockup-in-jffs2_reserve_space_gc > fs/jffs2/nodemgmt.c > --- a/fs/jffs2/nodemgmt.c~jffs2-avoid-soft-lockup-in-jffs2_reserve_space_gc > +++ a/fs/jffs2/nodemgmt.c > @@ -211,20 +211,25 @@ out: > int jffs2_reserve_space_gc(struct jffs2_sb_info *c, uint32_t minsize, > uint32_t *len, uint32_t sumsize) > { > - int ret = -EAGAIN; > + int ret; > minsize = PAD(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(); Just curious: would this be a place to use cond_resched_lock(), and keep the lock outside the loop? > + else > + break; > } > - spin_unlock(&c->erase_completion_lock); > if (!ret) > ret = jffs2_prealloc_raw_node_refs(c, c->nextblock, 1); > Anyway, pushed to l2-mtd.git. Thanks, Brian -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
