make it possible to reduce kmem pressure by letting some pools use a more

accomodating allocator. an interrupt safe pool may also be used in process
context, as indicated by waitok flags. thanks to the garbage collector, we
can always free pages in process context. the only complication is where
to put the pages. solve this by saving the allocation flags in the pool
page header so the free function can examine them.
not actually used in this diff. (coming soon.)
arm testing and compile fixes from phessler

1 files changed, 14 insertions, 24 deletions

diff --git a/sys/kern/subr_pool.c b/sys/kern/subr_pool.c
index 4837ba927fc..fbe077a5d61 100644
--- a/sys/kern/subr_pool.c
+++ b/sys/kern/subr_pool.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: subr_pool.c,v 1.223 2018/06/08 15:38:15 guenther Exp $	*/
+/*	$OpenBSD: subr_pool.c,v 1.224 2019/02/10 20:02:37 tedu Exp $	*/
 /*	$NetBSD: subr_pool.c,v 1.61 2001/09/26 07:14:56 chs Exp $	*/
 
 /*-
@@ -155,6 +155,7 @@ struct pool_page_header {
 	caddr_t			ph_colored;	/* page's colored address */
 	unsigned long		ph_magic;
 	int			ph_tick;
+	int			ph_flags;
 };
 #define POOL_MAGICBIT (1 << 3) /* keep away from perturbed low bits */
 #define POOL_PHPOISON(ph) ISSET((ph)->ph_magic, POOL_MAGICBIT)
@@ -225,13 +226,13 @@ void	 pool_get_done(struct pool *, void *, void *);
 void	 pool_runqueue(struct pool *, int);
 
 void	*pool_allocator_alloc(struct pool *, int, int *);
-void	 pool_allocator_free(struct pool *, void *);
+void	 pool_allocator_free(struct pool *, int, void *);
 
 /*
  * The default pool allocator.
  */
 void	*pool_page_alloc(struct pool *, int, int *);
-void	pool_page_free(struct pool *, void *);
+void	pool_page_free(struct pool *, int, void *);
 
 /*
  * safe for interrupts; this is the default allocator
@@ -243,7 +244,7 @@ struct pool_allocator pool_allocator_single = {
 };
 
 void	*pool_multi_alloc(struct pool *, int, int *);
-void	pool_multi_free(struct pool *, void *);
+void	pool_multi_free(struct pool *, int, void *);
 
 struct pool_allocator pool_allocator_multi = {
 	pool_multi_alloc,
@@ -252,7 +253,7 @@ struct pool_allocator pool_allocator_multi = {
 };
 
 void	*pool_multi_alloc_ni(struct pool *, int, int *);
-void	pool_multi_free_ni(struct pool *, void *);
+void	pool_multi_free_ni(struct pool *, int, void *);
 
 struct pool_allocator pool_allocator_multi_ni = {
 	pool_multi_alloc_ni,
@@ -787,7 +788,6 @@ pool_do_get(struct pool *pp, int flags, int *slowdown)
 void
 pool_put(struct pool *pp, void *v)
 {
-	struct pool_page_header *ph, *freeph = NULL;
 
 #ifdef DIAGNOSTIC
 	if (v == NULL)
@@ -808,19 +808,8 @@ pool_put(struct pool *pp, void *v)
 	pp->pr_nout--;
 	pp->pr_nput++;
 
-	/* is it time to free a page? */
-	if (pp->pr_nidle > pp->pr_maxpages &&
-	    (ph = TAILQ_FIRST(&pp->pr_emptypages)) != NULL &&
-	    (ticks - ph->ph_tick) > (hz * pool_wait_free)) {
-		freeph = ph;
-		pool_p_remove(pp, freeph);
-	}
-
 	pl_leave(pp, &pp->pr_lock);
 
-	if (freeph != NULL)
-		pool_p_free(pp, freeph);
-
 	if (!TAILQ_EMPTY(&pp->pr_requests)) {
 		pl_enter(pp, &pp->pr_requests_lock);
 		pool_runqueue(pp, PR_NOWAIT);
@@ -933,10 +922,11 @@ pool_p_alloc(struct pool *pp, int flags, int *slowdown)
 	else {
 		ph = pool_get(&phpool, flags);
 		if (ph == NULL) {
-			pool_allocator_free(pp, addr);
+			pool_allocator_free(pp, flags, addr);
 			return (NULL);
 		}
 	}
+	ph->ph_flags = flags;
 
 	XSIMPLEQ_INIT(&ph->ph_items);
 	ph->ph_page = addr;
@@ -1010,7 +1000,7 @@ pool_p_free(struct pool *pp, struct pool_page_header *ph)
 #endif
 	}
 
-	pool_allocator_free(pp, ph->ph_page);
+	pool_allocator_free(pp, ph->ph_flags, ph->ph_page);
 
 	if (!POOL_INPGHDR(pp))
 		pool_put(&phpool, ph);
@@ -1616,11 +1606,11 @@ pool_allocator_alloc(struct pool *pp, int flags, int *slowdown)
 }
 
 void
-pool_allocator_free(struct pool *pp, void *v)
+pool_allocator_free(struct pool *pp, int flags, void *v)
 {
 	struct pool_allocator *pa = pp->pr_alloc;
 
-	(*pa->pa_free)(pp, v);
+	(*pa->pa_free)(pp, flags, v);
 }
 
 void *
@@ -1635,7 +1625,7 @@ pool_page_alloc(struct pool *pp, int flags, int *slowdown)
 }
 
 void
-pool_page_free(struct pool *pp, void *v)
+pool_page_free(struct pool *pp, int flags, void *v)
 {
 	km_free(v, pp->pr_pgsize, &kv_page, pp->pr_crange);
 }
@@ -1662,7 +1652,7 @@ pool_multi_alloc(struct pool *pp, int flags, int *slowdown)
 }
 
 void
-pool_multi_free(struct pool *pp, void *v)
+pool_multi_free(struct pool *pp, int flags, void *v)
 {
 	struct kmem_va_mode kv = kv_intrsafe;
 	int s;
@@ -1696,7 +1686,7 @@ pool_multi_alloc_ni(struct pool *pp, int flags, int *slowdown)
 }
 
 void
-pool_multi_free_ni(struct pool *pp, void *v)
+pool_multi_free_ni(struct pool *pp, int flags, void *v)
 {
 	struct kmem_va_mode kv = kv_any;