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:[:[:...]] + 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);