diff options
| -rw-r--r-- | Documentation/kernel-parameters.txt | 6 | ||||
| -rw-r--r-- | include/linux/sunrpc/svc.h | 1 | ||||
| -rw-r--r-- | include/linux/sunrpc/svc_xprt.h | 1 | ||||
| -rw-r--r-- | net/sunrpc/svc_xprt.c | 39 |
4 files changed, 44 insertions, 3 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 82b42c9..48ba6d2 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -3832,6 +3832,12 @@ bytes respectively. Such letter suffixes can also be entirely omitted. using these two parameters to set the minimum and maximum port values. + sunrpc.svc_rpc_per_connection_limit= + [NFS,SUNRPC] + Limit the number of requests that the server will + process in parallel from a single connection. + The default value is 0 (no limit). + sunrpc.pool_mode= [NFS] Control how the NFS server code allocates CPUs to diff --git a/include/linux/sunrpc/svc.h b/include/linux/sunrpc/svc.h index 7ca44fb..7321ae9 100644 --- a/include/linux/sunrpc/svc.h +++ b/include/linux/sunrpc/svc.h @@ -268,6 +268,7 @@ struct svc_rqst { * cache pages */ #define RQ_VICTIM (5) /* about to be shut down */ #define RQ_BUSY (6) /* request is busy */ +#define RQ_DATA (7) /* request has data */ unsigned long rq_flags; /* flags field */ void * rq_argp; /* decoded arguments */ diff --git a/include/linux/sunrpc/svc_xprt.h b/include/linux/sunrpc/svc_xprt.h index 79ba508..ad899ff 100644 --- a/include/linux/sunrpc/svc_xprt.h +++ b/include/linux/sunrpc/svc_xprt.h @@ -69,6 +69,7 @@ struct svc_xprt { struct svc_serv *xpt_server; /* service for transport */ atomic_t xpt_reserved; /* space on outq that is rsvd */ + atomic_t xpt_nr_rqsts; /* Number of requests */ struct mutex xpt_mutex; /* to serialize sending data */ spinlock_t xpt_lock; /* protects sk_deferred * and xpt_auth_cache */ diff --git a/net/sunrpc/svc_xprt.c b/net/sunrpc/svc_xprt.c index e7082a4..2adc8db 100644 --- a/net/sunrpc/svc_xprt.c +++ b/net/sunrpc/svc_xprt.c @@ -21,6 +21,10 @@ #define RPCDBG_FACILITY RPCDBG_SVCXPRT +static unsigned int svc_rpc_per_connection_limit __read_mostly; +module_param(svc_rpc_per_connection_limit, uint, 0644); + + static struct svc_deferred_req *svc_deferred_dequeue(struct svc_xprt *xprt); static int svc_deferred_recv(struct svc_rqst *rqstp); static struct cache_deferred_req *svc_defer(struct cache_req *req); @@ -329,12 +333,41 @@ char *svc_print_addr(struct svc_rqst *rqstp, char *buf, size_t len) } EXPORT_SYMBOL_GPL(svc_print_addr); +static bool svc_xprt_slots_in_range(struct svc_xprt *xprt) +{ + unsigned int limit = svc_rpc_per_connection_limit; + int nrqsts = atomic_read(&xprt->xpt_nr_rqsts); + + return limit == 0 || (nrqsts >= 0 && nrqsts < limit); +} + +static bool svc_xprt_reserve_slot(struct svc_rqst *rqstp, struct svc_xprt *xprt) +{ + if (!test_bit(RQ_DATA, &rqstp->rq_flags)) { + if (!svc_xprt_slots_in_range(xprt)) + return false; + atomic_inc(&xprt->xpt_nr_rqsts); + set_bit(RQ_DATA, &rqstp->rq_flags); + } + return true; +} + +static void svc_xprt_release_slot(struct svc_rqst *rqstp) +{ + struct svc_xprt *xprt = rqstp->rq_xprt; + if (test_and_clear_bit(RQ_DATA, &rqstp->rq_flags)) { + atomic_dec(&xprt->xpt_nr_rqsts); + svc_xprt_enqueue(xprt); + } +} + static bool svc_xprt_has_something_to_do(struct svc_xprt *xprt) { if (xprt->xpt_flags & ((1<<XPT_CONN)|(1<<XPT_CLOSE))) return true; if (xprt->xpt_flags & ((1<<XPT_DATA)|(1<<XPT_DEFERRED))) { - if (xprt->xpt_ops->xpo_has_wspace(xprt)) + if (xprt->xpt_ops->xpo_has_wspace(xprt) && + svc_xprt_slots_in_range(xprt)) return true; trace_svc_xprt_no_write_space(xprt); return false; @@ -516,8 +549,8 @@ static void svc_xprt_release(struct svc_rqst *rqstp) rqstp->rq_res.head[0].iov_len = 0; svc_reserve(rqstp, 0); + svc_xprt_release_slot(rqstp); rqstp->rq_xprt = NULL; - svc_xprt_put(xprt); } @@ -785,7 +818,7 @@ static int svc_handle_xprt(struct svc_rqst *rqstp, struct svc_xprt *xprt) svc_add_new_temp_xprt(serv, newxpt); else module_put(xprt->xpt_class->xcl_owner); - } else { + } else if (svc_xprt_reserve_slot(rqstp, xprt)) { /* XPT_DATA|XPT_DEFERRED case: */ dprintk("svc: server %p, pool %u, transport %p, inuse=%d\n", rqstp, rqstp->rq_pool->sp_id, xprt, |
