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| author | Jeff Layton <jlayton@poochiereds.net> | 2015-03-20 22:15:14 +0300 |
|---|---|---|
| committer | Trond Myklebust <trond.myklebust@primarydata.com> | 2015-04-23 21:38:07 +0300 |
| commit | 5d05e54af3cdbb13cf19c557ff2184781b91a22c (patch) | |
| tree | f67bf3bdb8ad1fd4cc61ec8d0e23dfafdcbd3f8b | |
| parent | f830f7ddd9165c8bd69127458627f03df4b1a406 (diff) | |
| download | linux-5d05e54af3cdbb13cf19c557ff2184781b91a22c.tar.xz | |
nfs: fix high load average due to callback thread sleeping
Chuck pointed out a problem that crept in with commit 6ffa30d3f734 (nfs:
don't call blocking operations while !TASK_RUNNING). Linux counts tasks
in uninterruptible sleep against the load average, so this caused the
system's load average to be pinned at at least 1 when there was a
NFSv4.1+ mount active.
Not a huge problem, but it's probably worth fixing before we get too
many complaints about it. This patch converts the code back to use
TASK_INTERRUPTIBLE sleep, simply has it flush any signals on each loop
iteration. In practice no one should really be signalling this thread at
all, so I think this is reasonably safe.
With this change, there's also no need to game the hung task watchdog so
we can also convert the schedule_timeout call back to a normal schedule.
Cc: <stable@vger.kernel.org>
Reported-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Jeff Layton <jeff.layton@primarydata.com>
Tested-by: Chuck Lever <chuck.lever@oracle.com>
Fixes: commit 6ffa30d3f734 (“nfs: don't call blocking . . .”)
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
| -rw-r--r-- | fs/nfs/callback.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/fs/nfs/callback.c b/fs/nfs/callback.c index 351be9205bf8..8d129bb7355a 100644 --- a/fs/nfs/callback.c +++ b/fs/nfs/callback.c @@ -128,7 +128,7 @@ nfs41_callback_svc(void *vrqstp) if (try_to_freeze()) continue; - prepare_to_wait(&serv->sv_cb_waitq, &wq, TASK_UNINTERRUPTIBLE); + prepare_to_wait(&serv->sv_cb_waitq, &wq, TASK_INTERRUPTIBLE); spin_lock_bh(&serv->sv_cb_lock); if (!list_empty(&serv->sv_cb_list)) { req = list_first_entry(&serv->sv_cb_list, @@ -142,10 +142,10 @@ nfs41_callback_svc(void *vrqstp) error); } else { spin_unlock_bh(&serv->sv_cb_lock); - /* schedule_timeout to game the hung task watchdog */ - schedule_timeout(60 * HZ); + schedule(); finish_wait(&serv->sv_cb_waitq, &wq); } + flush_signals(current); } return 0; } |