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| author | Jeff Layton <jlayton@poochiereds.net> | 2015-06-03 23:14:25 +0300 |
|---|---|---|
| committer | Trond Myklebust <trond.myklebust@primarydata.com> | 2015-06-11 01:26:14 +0300 |
| commit | 3c87ef6efb40f0e339d705c194b2224f854ec38e (patch) | |
| tree | 2878ea261637cf6c85ab69b9cbde70a036b1e3a2 /include/linux/sunrpc | |
| parent | 0d2a970d0ae55086520e1e58e572a7acd519429c (diff) | |
| download | linux-3c87ef6efb40f0e339d705c194b2224f854ec38e.tar.xz | |
sunrpc: keep a count of swapfiles associated with the rpc_clnt
Jerome reported seeing a warning pop when working with a swapfile on
NFS. The nfs_swap_activate can end up calling sk_set_memalloc while
holding the rcu_read_lock and that function can sleep.
To fix that, we need to take a reference to the xprt while holding the
rcu_read_lock, set the socket up for swapping and then drop that
reference. But, xprt_put is not exported and having NFS deal with the
underlying xprt is a bit of layering violation anyway.
Fix this by adding a set of activate/deactivate functions that take a
rpc_clnt pointer instead of an rpc_xprt, and have nfs_swap_activate and
nfs_swap_deactivate call those.
Also, add a per-rpc_clnt atomic counter to keep track of the number of
active swapfiles associated with it. When the counter does a 0->1
transition, we enable swapping on the xprt, when we do a 1->0 transition
we disable swapping on it.
This also allows us to be a bit more selective with the RPC_TASK_SWAPPER
flag. If non-swapper and swapper clnts are sharing a xprt, then we only
need to flag the tasks from the swapper clnt with that flag.
Acked-by: Mel Gorman <mgorman@suse.de>
Reported-by: Jerome Marchand <jmarchan@redhat.com>
Signed-off-by: Jeff Layton <jeff.layton@primarydata.com>
Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Diffstat (limited to 'include/linux/sunrpc')
| -rw-r--r-- | include/linux/sunrpc/clnt.h | 1 | ||||
| -rw-r--r-- | include/linux/sunrpc/sched.h | 16 |
2 files changed, 17 insertions, 0 deletions
diff --git a/include/linux/sunrpc/clnt.h b/include/linux/sunrpc/clnt.h index 598ba80ec30c..131032f15cc1 100644 --- a/include/linux/sunrpc/clnt.h +++ b/include/linux/sunrpc/clnt.h @@ -56,6 +56,7 @@ struct rpc_clnt { struct rpc_rtt * cl_rtt; /* RTO estimator data */ const struct rpc_timeout *cl_timeout; /* Timeout strategy */ + atomic_t cl_swapper; /* swapfile count */ int cl_nodelen; /* nodename length */ char cl_nodename[UNX_MAXNODENAME+1]; struct rpc_pipe_dir_head cl_pipedir_objects; diff --git a/include/linux/sunrpc/sched.h b/include/linux/sunrpc/sched.h index 2aa68976a482..d703f0ef37d8 100644 --- a/include/linux/sunrpc/sched.h +++ b/include/linux/sunrpc/sched.h @@ -268,4 +268,20 @@ static inline void rpc_assign_waitqueue_name(struct rpc_wait_queue *q, } #endif +#if IS_ENABLED(CONFIG_SUNRPC_SWAP) +int rpc_clnt_swap_activate(struct rpc_clnt *clnt); +void rpc_clnt_swap_deactivate(struct rpc_clnt *clnt); +#else +static inline int +rpc_clnt_swap_activate(struct rpc_clnt *clnt) +{ + return -EINVAL; +} + +static inline void +rpc_clnt_swap_deactivate(struct rpc_clnt *clnt) +{ +} +#endif /* CONFIG_SUNRPC_SWAP */ + #endif /* _LINUX_SUNRPC_SCHED_H_ */ |