于 2012年08月31日 22:02, Jeff Layton 写道: > On Fri, 31 Aug 2012 13:40:16 +0800 > gchen <gang.chen@xxxxxxxxxxx> wrote: > >> Hi linux-nfs@xxxxxxxxxxxxxxx >> >> I have 1 question, and also 2 conclusions which need confirm. >> >> >> 1) Question: >> >> Jeff Layton said in Red Hat Bugzilla (bug 848706): >> "Have configuration where the same host is acting as both NFS client >> and server. That's a configuration known to cause deadlocks." >> >> Does it mean that the public Linux kernel (not Red Hat) also can cause >> deadlocks if NFS client and server are under the same machine ? >> > Yes. I will communicate with LTP (Linux Test Project) to confirm it, too. And, it will be better if other members in linux-nfs@xxxxxxxxxxxxxxx also confirm it. >> 2) Confirm 1: (better by Jeff Layton) >> >> For function nfs_commit_set_lock in ./fs/nfs/write.c >> >> for latest public kernel version: >> the parameters of out_of_line_wait_on_bit_lock() are >> (&nfsi->flags, NFS_INO_COMMIT, nfs_wait_killable, TASK_KILLABLE) >> for Red Hat kernel version: kernel-2.6.18-308.4.1.el5 >> the parameters of out_of_line_wait_on_bit_lock() are >> (&nfsi->flags, NFS_INO_COMMIT, >> nfs_wait_bit_uninterruptible, TASK_UNINTERRUPTIBLE) >> >> It means for red hat version: >> when deadlock occurs, we can not boot machine in normal way >> (it is true for my test machine, the deadlock task can not be killed) >> It means for public kernel version: >> "Assume deadlock occurs", we can still boot machine in normal way, >> because the task can be killed. >> >> Is what I said above correct ? >> > Not sure I understand your question. RHEL5 doesn't have support for > TASK_KILLABLE, and I didn't backport it, hence the difference in that > function. I agree with what you said above. Thanks for your confirmation. >> 3) Confirm 2: >> >> Is LTP (Linux Test Project) still a suitable test tools for public kernel ? >> (for ltp-full-20100331.gz stress test, it mounts NFS on local machine, >> and the latest LTP ltp-full-20120401.bz2 also seems the same). >> > That I'm not sure of. All I can tell you is that mounts over loopback > (or similar configurations) are easily deadlockable under load. > I will communicate with LTP (Linux Test Project) about these informations. Thanks. gchen. Asianux Corporation. -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
