On Sun, 2014-11-23 at 10:14 -0500, Chris Mason wrote: > Hi Linus, > > My for-linus branch:
Not sure if this is related, but with -rc4, on this ppc64el box, when grub updates (it starts trying to mount everything under the sun with every filesystem), the box hangs with: [ 177.344522] INFO: rcu_sched detected stalls on CPUs/tasks: { 8} (detected by 9, t=25883 jiffies, g=3642, c=3641, q=5206) With xmon I can catch it with this backtrace: [link register ] d00000000ecec3f8 test_check_exists+0x1f8/0x280 [btrfs] [c000000f0cc63930] d00000000ecec2b0 test_check_exists+0xb0/0x280 [btrfs] (unreliable) [c000000f0cc63990] d00000000ed2a4b4 btrfs_test_free_space_cache+0x774/0x1150 [btrfs] [c000000f0cc63a20] d00000000ed30f04 init_btrfs_fs+0x11c/0x210 [btrfs] [c000000f0cc63a90] c00000000000b4dc do_one_initcall+0x12c/0x280 [c000000f0cc63b60] c0000000001628b8 load_module+0x2088/0x2970 [c000000f0cc63d50] c0000000001633d0 SyS_finit_module+0xc0/0x120 [c000000f0cc63e30] c00000000000927c syscall_exit+0x0/0x7c --- Exception: c01 (System Call) at 00003fff88697184 Note that afaik there isn't any btrfs partition on any disk on that machine... well not that I know of :) Cheers, Ben. > git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs.git for-linus > > Has a fix for a long standing deadlock that we've been trying to nail > down for a while. It ended up being a bad interaction with the fair > reader/writer locks and the order btrfs reacquires locks in the btree. > > Chris Mason (1) commits (+25/-15): > btrfs: fix lockups from btrfs_clear_path_blocking > > Total: (1) commits (+25/-15) > > fs/btrfs/ctree.c | 14 ++------------ > fs/btrfs/locking.c | 24 +++++++++++++++++++++--- > fs/btrfs/locking.h | 2 ++ > 3 files changed, 25 insertions(+), 15 deletions(-) > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majord...@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/