Gitweb:
http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=42a7fc4a6598221f1a547a76cdd45a8ab4d90e93
Commit: 42a7fc4a6598221f1a547a76cdd45a8ab4d90e93
Parent: cda1fd4abd773216a888487af0170d0cc3d50454
Author: Greg Banks <[EMAIL PROTECTED]>
AuthorDate: Tue Mar 6 01:42:23 2007 -0800
Committer: Linus Torvalds <[EMAIL PROTECTED]>
CommitDate: Tue Mar 6 09:30:26 2007 -0800
[PATCH] knfsd: provide sunrpc pool_mode module option
Provide a module param "pool_mode" for sunrpc.ko which allows a sysadmin to
choose the mode for mapping NFS thread service pools to CPUs. Values are:
auto choose a mapping mode heuristically
global (default, same as the pre-2.6.19 code) a single global pool
percpu one pool per CPU
pernode one pool per NUMA node
Note that since 2.6.19 the hardcoded behaviour has been "auto", this patch
makes the default "global".
The pool mode can be changed after boot/modprobe using /sys, if the NFS and
lockd services have been shut down. A useful side effect of this change is
to
fix a small memory leak when unloading the module.
Signed-off-by: Greg Banks <[EMAIL PROTECTED]>
Signed-off-by: Neil Brown <[EMAIL PROTECTED]>
Signed-off-by: Andrew Morton <[EMAIL PROTECTED]>
Signed-off-by: Linus Torvalds <[EMAIL PROTECTED]>
---
Documentation/kernel-parameters.txt | 16 ++++
net/sunrpc/svc.c | 133 ++++++++++++++++++++++++++++++-----
2 files changed, 130 insertions(+), 19 deletions(-)
diff --git a/Documentation/kernel-parameters.txt
b/Documentation/kernel-parameters.txt
index 03eb5ed..6e92ba6 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 f960b13..b4db53f 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);
-
To unsubscribe from this list: send the line "unsubscribe git-commits-head" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at http://vger.kernel.org/majordomo-info.html
