[PATCH] knfsd: allow admin to set nthreads per node
Add /proc/fs/nfsd/pool_threads which allows the sysadmin (or a userspace
daemon) to read and change the number of nfsd threads in each pool. The
format is a list of space-separated integers, one per pool.
Signed-off-by: Greg Banks <gnb@melbourne.sgi.com>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/fs/nfsd/nfssvc.c b/fs/nfsd/nfssvc.c
index 0029cb2..1944305 100644
--- a/fs/nfsd/nfssvc.c
+++ b/fs/nfsd/nfssvc.c
@@ -238,6 +238,80 @@
return 0;
}
+int nfsd_nrpools(void)
+{
+ if (nfsd_serv == NULL)
+ return 0;
+ else
+ return nfsd_serv->sv_nrpools;
+}
+
+int nfsd_get_nrthreads(int n, int *nthreads)
+{
+ int i = 0;
+
+ if (nfsd_serv != NULL) {
+ for (i = 0; i < nfsd_serv->sv_nrpools && i < n; i++)
+ nthreads[i] = nfsd_serv->sv_pools[i].sp_nrthreads;
+ }
+
+ return 0;
+}
+
+int nfsd_set_nrthreads(int n, int *nthreads)
+{
+ int i = 0;
+ int tot = 0;
+ int err = 0;
+
+ if (nfsd_serv == NULL || n <= 0)
+ return 0;
+
+ if (n > nfsd_serv->sv_nrpools)
+ n = nfsd_serv->sv_nrpools;
+
+ /* enforce a global maximum number of threads */
+ tot = 0;
+ for (i = 0; i < n; i++) {
+ if (nthreads[i] > NFSD_MAXSERVS)
+ nthreads[i] = NFSD_MAXSERVS;
+ tot += nthreads[i];
+ }
+ if (tot > NFSD_MAXSERVS) {
+ /* total too large: scale down requested numbers */
+ for (i = 0; i < n && tot > 0; i++) {
+ int new = nthreads[i] * NFSD_MAXSERVS / tot;
+ tot -= (nthreads[i] - new);
+ nthreads[i] = new;
+ }
+ for (i = 0; i < n && tot > 0; i++) {
+ nthreads[i]--;
+ tot--;
+ }
+ }
+
+ /*
+ * There must always be a thread in pool 0; the admin
+ * can't shut down NFS completely using pool_threads.
+ */
+ if (nthreads[0] == 0)
+ nthreads[0] = 1;
+
+ /* apply the new numbers */
+ lock_kernel();
+ svc_get(nfsd_serv);
+ for (i = 0; i < n; i++) {
+ err = svc_set_num_threads(nfsd_serv, &nfsd_serv->sv_pools[i],
+ nthreads[i]);
+ if (err)
+ break;
+ }
+ svc_destroy(nfsd_serv);
+ unlock_kernel();
+
+ return err;
+}
+
int
nfsd_svc(unsigned short port, int nrservs)
{