diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 03eb5ed503f7745e9e30f177fd35baba8ff96779..6e92ba61f7c0ea18b86557eec2bd17f2ece5d9ca 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -1685,6 +1685,22 @@ and is between 256 and 4096 characters. It is defined in the file
stifb= [HW]
Format: bpp:<bpp1>[:<bpp2>[:<bpp3>...]]
+ sunrpc.pool_mode=
+ [NFS]
+ Control how the NFS server code allocates CPUs to
+ service thread pools. Depending on how many NICs
+ you have and where their interrupts are bound, this
+ option will affect which CPUs will do NFS serving.
+ Note: this parameter cannot be changed while the
+ NFS server is running.
+
+ auto the server chooses an appropriate mode
+ automatically using heuristics
+ global a single global pool contains all CPUs
+ percpu one pool for each CPU
+ pernode one pool for each NUMA node (equivalent
+ to global on non-NUMA machines)
+
swiotlb= [IA-64] Number of I/O TLB slabs
switches= [HW,M68k]
diff --git a/net/sunrpc/svc.c b/net/sunrpc/svc.c
index f960b138236fceac6c5fa78e187c17103dd88b6c..b4db53ff143577a06fd72d2ef83418b4de194e9d 100644
--- a/net/sunrpc/svc.c
+++ b/net/sunrpc/svc.c
@@ -27,22 +27,26 @@
#define RPCDBG_FACILITY RPCDBG_SVCDSP
+#define svc_serv_is_pooled(serv) ((serv)->sv_function)
+
/*
* Mode for mapping cpus to pools.
*/
enum {
- SVC_POOL_NONE = -1, /* uninitialised, choose one of the others */
+ SVC_POOL_AUTO = -1, /* choose one of the others */
SVC_POOL_GLOBAL, /* no mapping, just a single global pool
* (legacy & UP mode) */
SVC_POOL_PERCPU, /* one pool per cpu */
SVC_POOL_PERNODE /* one pool per numa node */
};
+#define SVC_POOL_DEFAULT SVC_POOL_GLOBAL
/*
* Structure for mapping cpus to pools and vice versa.
* Setup once during sunrpc initialisation.
*/
static struct svc_pool_map {
+ int count; /* How many svc_servs use us */
int mode; /* Note: int not enum to avoid
* warnings about "enumeration value
* not handled in switch" */
@@ -50,9 +54,63 @@ static struct svc_pool_map {
unsigned int *pool_to; /* maps pool id to cpu or node */
unsigned int *to_pool; /* maps cpu or node to pool id */
} svc_pool_map = {
- .mode = SVC_POOL_NONE
+ .count = 0,
+ .mode = SVC_POOL_DEFAULT
};
+static DEFINE_MUTEX(svc_pool_map_mutex);/* protects svc_pool_map.count only */
+
+static int
+param_set_pool_mode(const char *val, struct kernel_param *kp)
+{
+ int *ip = (int *)kp->arg;
+ struct svc_pool_map *m = &svc_pool_map;
+ int err;
+
+ mutex_lock(&svc_pool_map_mutex);
+
+ err = -EBUSY;
+ if (m->count)
+ goto out;
+
+ err = 0;
+ if (!strncmp(val, "auto", 4))
+ *ip = SVC_POOL_AUTO;
+ else if (!strncmp(val, "global", 6))
+ *ip = SVC_POOL_GLOBAL;
+ else if (!strncmp(val, "percpu", 6))
+ *ip = SVC_POOL_PERCPU;
+ else if (!strncmp(val, "pernode", 7))
+ *ip = SVC_POOL_PERNODE;
+ else
+ err = -EINVAL;
+
+out:
+ mutex_unlock(&svc_pool_map_mutex);
+ return err;
+}
+
+static int
+param_get_pool_mode(char *buf, struct kernel_param *kp)
+{
+ int *ip = (int *)kp->arg;
+
+ switch (*ip)
+ {
+ case SVC_POOL_AUTO:
+ return strlcpy(buf, "auto", 20);
+ case SVC_POOL_GLOBAL:
+ return strlcpy(buf, "global", 20);
+ case SVC_POOL_PERCPU:
+ return strlcpy(buf, "percpu", 20);
+ case SVC_POOL_PERNODE:
+ return strlcpy(buf, "pernode", 20);
+ default:
+ return sprintf(buf, "%d", *ip);
+ }
+}
+module_param_call(pool_mode, param_set_pool_mode, param_get_pool_mode,
+ &svc_pool_map.mode, 0644);
/*
* Detect best pool mapping mode heuristically,
@@ -166,18 +224,25 @@ svc_pool_map_init_pernode(struct svc_pool_map *m)
/*
- * Build the global map of cpus to pools and vice versa.
+ * Add a reference to the global map of cpus to pools (and
+ * vice versa). Initialise the map if we're the first user.
+ * Returns the number of pools.
*/
static unsigned int
-svc_pool_map_init(void)
+svc_pool_map_get(void)
{
struct svc_pool_map *m = &svc_pool_map;
int npools = -1;
- if (m->mode != SVC_POOL_NONE)
+ mutex_lock(&svc_pool_map_mutex);
+
+ if (m->count++) {
+ mutex_unlock(&svc_pool_map_mutex);
return m->npools;
+ }
- m->mode = svc_pool_map_choose_mode();
+ if (m->mode == SVC_POOL_AUTO)
+ m->mode = svc_pool_map_choose_mode();
switch (m->mode) {
case SVC_POOL_PERCPU:
@@ -195,9 +260,36 @@ svc_pool_map_init(void)
}
m->npools = npools;
+ mutex_unlock(&svc_pool_map_mutex);
return m->npools;
}
+
+/*
+ * Drop a reference to the global map of cpus to pools.
+ * When the last reference is dropped, the map data is
+ * freed; this allows the sysadmin to change the pool
+ * mode using the pool_mode module option without
+ * rebooting or re-loading sunrpc.ko.
+ */
+static void
+svc_pool_map_put(void)
+{
+ struct svc_pool_map *m = &svc_pool_map;
+
+ mutex_lock(&svc_pool_map_mutex);
+
+ if (!--m->count) {
+ m->mode = SVC_POOL_DEFAULT;
+ kfree(m->to_pool);
+ kfree(m->pool_to);
+ m->npools = 0;
+ }
+
+ mutex_unlock(&svc_pool_map_mutex);
+}
+
+
/*
* Set the current thread's cpus_allowed mask so that it
* will only run on cpus in the given pool.
@@ -212,10 +304,9 @@ svc_pool_map_set_cpumask(unsigned int pidx, cpumask_t *oldmask)
/*
* The caller checks for sv_nrpools > 1, which
- * implies that we've been initialized and the
- * map mode is not NONE.
+ * implies that we've been initialized.
*/
- BUG_ON(m->mode == SVC_POOL_NONE);
+ BUG_ON(m->count == 0);
switch (m->mode)
{
@@ -246,18 +337,19 @@ svc_pool_for_cpu(struct svc_serv *serv, int cpu)
unsigned int pidx = 0;
/*
- * SVC_POOL_NONE happens in a pure client when
+ * An uninitialised map happens in a pure client when
* lockd is brought up, so silently treat it the
* same as SVC_POOL_GLOBAL.
*/
-
- switch (m->mode) {
- case SVC_POOL_PERCPU:
- pidx = m->to_pool[cpu];
- break;
- case SVC_POOL_PERNODE:
- pidx = m->to_pool[cpu_to_node(cpu)];
- break;
+ if (svc_serv_is_pooled(serv)) {
+ switch (m->mode) {
+ case SVC_POOL_PERCPU:
+ pidx = m->to_pool[cpu];
+ break;
+ case SVC_POOL_PERNODE:
+ pidx = m->to_pool[cpu_to_node(cpu)];
+ break;
+ }
}
return &serv->sv_pools[pidx % serv->sv_nrpools];
}
@@ -347,7 +439,7 @@ svc_create_pooled(struct svc_program *prog, unsigned int bufsize,
svc_thread_fn func, int sig, struct module *mod)
{
struct svc_serv *serv;
- unsigned int npools = svc_pool_map_init();
+ unsigned int npools = svc_pool_map_get();
serv = __svc_create(prog, bufsize, npools, shutdown);
@@ -397,6 +489,9 @@ svc_destroy(struct svc_serv *serv)
cache_clean_deferred(serv);
+ if (svc_serv_is_pooled(serv))
+ svc_pool_map_put();
+
/* Unregister service with the portmapper */
svc_register(serv, 0, 0);
kfree(serv->sv_pools);