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| author | Dai Ngo <dai.ngo@oracle.com> | 2024-01-30 11:38:25 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-04-13 12:50:16 +0200 |
| commit | 56199ebbcbbcc36658c2212b854b37dff8419e52 (patch) | |
| tree | f355edafff493f589da2795d6106ff5be96151c3 | |
| parent | 34f0cabed648481fa21d50a551524115f9326257 (diff) | |
| download | linux-stable-56199ebbcbbcc36658c2212b854b37dff8419e52.tar.gz linux-stable-56199ebbcbbcc36658c2212b854b37dff8419e52.tar.bz2 linux-stable-56199ebbcbbcc36658c2212b854b37dff8419e52.zip | |
SUNRPC: increase size of rpc_wait_queue.qlen from unsigned short to unsigned int
[ Upstream commit 2c35f43b5a4b9cdfaa6fdd946f5a212615dac8eb ]
When the NFS client is under extreme load the rpc_wait_queue.qlen counter
can be overflowed. Here is an instant of the backlog queue overflow in a
real world environment shown by drgn helper:
rpc_task_stats(rpc_clnt):
-------------------------
rpc_clnt: 0xffff92b65d2bae00
rpc_xprt: 0xffff9275db64f000
Queue: sending[64887] pending[524] backlog[30441] binding[0]
XMIT task: 0xffff925c6b1d8e98
WRITE: 750654
__dta_call_status_580: 65463
__dta_call_transmit_status_579: 1
call_reserveresult: 685189
nfs_client_init_is_complete: 1
COMMIT: 584
call_reserveresult: 573
__dta_call_status_580: 11
ACCESS: 1
__dta_call_status_580: 1
GETATTR: 10
__dta_call_status_580: 4
call_reserveresult: 6
751249 tasks for server 111.222.333.444
Total tasks: 751249
count_rpc_wait_queues(xprt):
----------------------------
**** rpc_xprt: 0xffff9275db64f000 num_reqs: 65511
wait_queue: xprt_binding[0] cnt: 0
wait_queue: xprt_binding[1] cnt: 0
wait_queue: xprt_binding[2] cnt: 0
wait_queue: xprt_binding[3] cnt: 0
rpc_wait_queue[xprt_binding].qlen: 0 maxpriority: 0
wait_queue: xprt_sending[0] cnt: 0
wait_queue: xprt_sending[1] cnt: 64887
wait_queue: xprt_sending[2] cnt: 0
wait_queue: xprt_sending[3] cnt: 0
rpc_wait_queue[xprt_sending].qlen: 64887 maxpriority: 3
wait_queue: xprt_pending[0] cnt: 524
wait_queue: xprt_pending[1] cnt: 0
wait_queue: xprt_pending[2] cnt: 0
wait_queue: xprt_pending[3] cnt: 0
rpc_wait_queue[xprt_pending].qlen: 524 maxpriority: 0
wait_queue: xprt_backlog[0] cnt: 0
wait_queue: xprt_backlog[1] cnt: 685801
wait_queue: xprt_backlog[2] cnt: 0
wait_queue: xprt_backlog[3] cnt: 0
rpc_wait_queue[xprt_backlog].qlen: 30441 maxpriority: 3 [task cnt mismatch]
There is no effect on operations when this overflow occurs. However
it causes confusion when trying to diagnose the performance problem.
Signed-off-by: Dai Ngo <dai.ngo@oracle.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | include/linux/sunrpc/sched.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/include/linux/sunrpc/sched.h b/include/linux/sunrpc/sched.h index 96837ae07822..ca0a568fd824 100644 --- a/include/linux/sunrpc/sched.h +++ b/include/linux/sunrpc/sched.h @@ -190,7 +190,7 @@ struct rpc_wait_queue { unsigned char maxpriority; /* maximum priority (0 if queue is not a priority queue) */ unsigned char priority; /* current priority */ unsigned char nr; /* # tasks remaining for cookie */ - unsigned short qlen; /* total # tasks waiting in queue */ + unsigned int qlen; /* total # tasks waiting in queue */ struct rpc_timer timer_list; #if IS_ENABLED(CONFIG_SUNRPC_DEBUG) || IS_ENABLED(CONFIG_TRACEPOINTS) const char * name; |