[src/trunk]: src Add pool_cache_invalidate_local() to the pool_cache(9) API, ...

[jym <jym%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/de691ec04c1d
branches:  trunk
changeset: 748003:de691ec04c1d
user:      jym <jym%NetBSD.org@localhost>
date:      Thu Oct 08 21:54:45 2009 +0000

description:
Add pool_cache_invalidate_local() to the pool_cache(9) API, to permit
per-CPU objects invalidation when cached in the pool cache.

See http://mail-index.netbsd.org/tech-kern/2009/10/05/msg006206.html .

Reviewed by bouyer@. Thanks!

diffstat:

 share/man/man9/Makefile     |   5 +-
 share/man/man9/pool_cache.9 |  18 ++++++++++-
 sys/kern/subr_pool.c        |  73 +++++++++++++++++++++++++++++++++-----------
 sys/sys/pool.h              |   3 +-
 4 files changed, 76 insertions(+), 23 deletions(-)

diffs (197 lines):

diff -r 4087061b24e1 -r de691ec04c1d share/man/man9/Makefile
--- a/share/man/man9/Makefile   Thu Oct 08 20:36:41 2009 +0000
+++ b/share/man/man9/Makefile   Thu Oct 08 21:54:45 2009 +0000
@@ -1,4 +1,4 @@
-#       $NetBSD: Makefile,v 1.294 2009/10/05 23:44:10 rmind Exp $
+#       $NetBSD: Makefile,v 1.295 2009/10/08 21:54:45 jym Exp $
 
 #      Makefile for section 9 (kernel function and variable) manual pages.
 
@@ -543,7 +543,8 @@
        pool_cache.9 pool_cache_put_paddr.9 \
        pool_cache.9 pool_cache_put.9 \
        pool_cache.9 pool_cache_destruct_object.9 \
-       pool_cache.9 pool_cache_invalidate.9
+       pool_cache.9 pool_cache_invalidate.9 \
+       pool_cache.9 pool_cache_invalidate_local.9
 MLINKS+=powerhook_establish.9 powerhook_disestablish.9
 MLINKS+=preempt.9 yield.9
 MLINKS+=ras.9 ras_lookup.9 \
diff -r 4087061b24e1 -r de691ec04c1d share/man/man9/pool_cache.9
--- a/share/man/man9/pool_cache.9       Thu Oct 08 20:36:41 2009 +0000
+++ b/share/man/man9/pool_cache.9       Thu Oct 08 21:54:45 2009 +0000
@@ -1,4 +1,4 @@
-.\"    $NetBSD: pool_cache.9,v 1.10 2009/09/06 19:46:24 jym Exp $
+.\"    $NetBSD: pool_cache.9,v 1.11 2009/10/08 21:54:45 jym Exp $
 .\"
 .\" Copyright (c)2003 YAMAMOTO Takashi,
 .\" All rights reserved.
@@ -67,6 +67,7 @@
 .Nm pool_cache_put ,
 .Nm pool_cache_destruct_object ,
 .Nm pool_cache_invalidate ,
+.Nm pool_cache_invalidate_local ,
 .Nm pool_cache_sethiwat ,
 .Nm pool_cache_setlowat
 .Nd resource-pool cache manager
@@ -108,6 +109,10 @@
 .Fn pool_cache_invalidate \
 "pool_cache_t pc"
 .Ft void
+.Fn pool_cache_invalidate_local \
+"pool_cache_t pc"
+.\" - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+.Ft void
 .Fn pool_cache_sethiwat \
 "pool_cache_t pc" "int nitems"
 .Ft void
@@ -280,6 +285,17 @@
 If relevant, the user must check for this condition when allocating
 items.
 .\" - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+.It Fn pool_cache_invalidate_local "pc"
+.Pp
+Invalidate local, current CPU pool cache
+.Fa pc .
+Destruct and release all objects in the local, current CPU cache.
+Only the Per-CPU caches associated to the current CPU calling the routine
+will be invalidated, meaning that stale items can still be allocated from
+other CPUs or the global cache.
+It is the caller's responsibility to ensure that such conditions do
+not occur.
+.\" - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 .It Fn pool_cache_sethiwat "pc" "nitems"
 .Pp
 A pool will attempt to increase its resource usage to keep up with the demand
diff -r 4087061b24e1 -r de691ec04c1d sys/kern/subr_pool.c
--- a/sys/kern/subr_pool.c      Thu Oct 08 20:36:41 2009 +0000
+++ b/sys/kern/subr_pool.c      Thu Oct 08 21:54:45 2009 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: subr_pool.c,v 1.174 2009/09/13 18:45:11 pooka Exp $    */
+/*     $NetBSD: subr_pool.c,v 1.175 2009/10/08 21:54:45 jym Exp $      */
 
 /*-
  * Copyright (c) 1997, 1999, 2000, 2002, 2007, 2008 The NetBSD Foundation, Inc.
@@ -31,7 +31,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: subr_pool.c,v 1.174 2009/09/13 18:45:11 pooka Exp $");
+__KERNEL_RCSID(0, "$NetBSD: subr_pool.c,v 1.175 2009/10/08 21:54:45 jym Exp $");
 
 #include "opt_ddb.h"
 #include "opt_pool.h"
@@ -188,6 +188,7 @@
                                    void **, paddr_t *, int);
 static void    pool_cache_cpu_init1(struct cpu_info *, pool_cache_t);
 static void    pool_cache_invalidate_groups(pool_cache_t, pcg_t *);
+static void    pool_cache_invalidate_cpu(pool_cache_t, u_int);
 static void    pool_cache_xcall(pool_cache_t);
 
 static int     pool_catchup(struct pool *);
@@ -2122,9 +2123,7 @@
 pool_cache_destroy(pool_cache_t pc)
 {
        struct pool *pp = &pc->pc_pool;
-       pool_cache_cpu_t *cc;
-       pcg_t *pcg;
-       int i;
+       u_int i;
 
        /* Remove it from the global list. */
        mutex_enter(&pool_head_lock);
@@ -2142,20 +2141,8 @@
        mutex_exit(&pp->pr_lock);
 
        /* Destroy per-CPU data */
-       for (i = 0; i < MAXCPUS; i++) {
-               if ((cc = pc->pc_cpus[i]) == NULL)
-                       continue;
-               if ((pcg = cc->cc_current) != &pcg_dummy) {
-                       pcg->pcg_next = NULL;
-                       pool_cache_invalidate_groups(pc, pcg);
-               }
-               if ((pcg = cc->cc_previous) != &pcg_dummy) {
-                       pcg->pcg_next = NULL;
-                       pool_cache_invalidate_groups(pc, pcg);
-               }
-               if (cc != &pc->pc_cpu0)
-                       pool_put(&cache_cpu_pool, cc);
-       }
+       for (i = 0; i < MAXCPUS; i++)
+               pool_cache_invalidate_cpu(pc, i);
 
        /* Finally, destroy it. */
        mutex_destroy(&pc->pc_lock);
@@ -2325,6 +2312,54 @@
        pool_cache_invalidate_groups(pc, part);
 }
 
+/*
+ * pool_cache_invalidate_local:
+ *
+ *     Invalidate all local ('current CPU') cached objects in
+ *     pool cache.
+ *     It is caller's responsibility to ensure that no operation is
+ *     taking place on this pool cache while doing the local invalidation.
+ */
+void
+pool_cache_invalidate_local(pool_cache_t pc)
+{
+       pool_cache_invalidate_cpu(pc, curcpu()->ci_index);
+}
+
+/*
+ * pool_cache_invalidate_cpu:
+ *
+ *     Invalidate all CPU-bound cached objects in pool cache, the CPU being
+ *     identified by its associated index.
+ *     It is caller's responsibility to ensure that no operation is
+ *     taking place on this pool cache while doing this invalidation.
+ *     WARNING: as no inter-CPU locking is enforced, trying to invalidate
+ *     pool cached objects from a CPU different from the one currently running
+ *     may result in an undefined behaviour.
+ */
+static void
+pool_cache_invalidate_cpu(pool_cache_t pc, u_int index)
+{
+
+       pool_cache_cpu_t *cc;
+       pcg_t *pcg;
+
+       if ((cc = pc->pc_cpus[index]) == NULL)
+               return;
+
+       if ((pcg = cc->cc_current) != &pcg_dummy) {
+               pcg->pcg_next = NULL;
+               pool_cache_invalidate_groups(pc, pcg);
+       }
+       if ((pcg = cc->cc_previous) != &pcg_dummy) {
+               pcg->pcg_next = NULL;
+               pool_cache_invalidate_groups(pc, pcg);
+       }
+       if (cc != &pc->pc_cpu0)
+               pool_put(&cache_cpu_pool, cc);
+
+}
+
 void
 pool_cache_set_drain_hook(pool_cache_t pc, void (*fn)(void *, int), void *arg)
 {
diff -r 4087061b24e1 -r de691ec04c1d sys/sys/pool.h
--- a/sys/sys/pool.h    Thu Oct 08 20:36:41 2009 +0000
+++ b/sys/sys/pool.h    Thu Oct 08 21:54:45 2009 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: pool.h,v 1.65 2009/09/13 18:45:12 pooka Exp $  */
+/*     $NetBSD: pool.h,v 1.66 2009/10/08 21:54:45 jym Exp $    */
 
 /*-
  * Copyright (c) 1997, 1998, 1999, 2000, 2007 The NetBSD Foundation, Inc.
@@ -321,6 +321,7 @@
 void           pool_cache_put_paddr(pool_cache_t, void *, paddr_t);
 void           pool_cache_destruct_object(pool_cache_t, void *);
 void           pool_cache_invalidate(pool_cache_t);
+void           pool_cache_invalidate_local(pool_cache_t);
 bool           pool_cache_reclaim(pool_cache_t);
 void           pool_cache_set_drain_hook(pool_cache_t,
                    void (*)(void *, int), void *);