Improve page allocator performance by using pool_cache for the

structure itself and allocating the backing page directly from the
hypervisor.

* initial write to a large tmpfs file is almost 2x faster
* truncating the file to 0 length after write is over 50% faster
* rewrite of the file is just slightly faster (indicating that
  kmem does a good job with caching, as expected)
This commit is contained in:
pooka 2010-09-07 07:47:36 +00:00
parent 31b69ed482
commit 5862500201
1 changed files with 30 additions and 8 deletions

View File

@ -1,4 +1,4 @@
/* $NetBSD: vm.c,v 1.89 2010/09/07 06:06:54 pooka Exp $ */
/* $NetBSD: vm.c,v 1.90 2010/09/07 07:47:36 pooka Exp $ */
/*
* Copyright (c) 2007-2010 Antti Kantee. All Rights Reserved.
@ -41,7 +41,7 @@
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: vm.c,v 1.89 2010/09/07 06:06:54 pooka Exp $");
__KERNEL_RCSID(0, "$NetBSD: vm.c,v 1.90 2010/09/07 07:47:36 pooka Exp $");
#include <sys/param.h>
#include <sys/atomic.h>
@ -115,6 +115,26 @@ const struct rb_tree_ops uvm_page_tree_ops = {
* vm pages
*/
static int
pgctor(void *arg, void *obj, int flags)
{
struct vm_page *pg = obj;
memset(pg, 0, sizeof(*pg));
pg->uanon = rump_hypermalloc(PAGE_SIZE, PAGE_SIZE, true, "pgalloc");
return 0;
}
static void
pgdtor(void *arg, void *obj)
{
struct vm_page *pg = obj;
rump_hyperfree(pg->uanon, PAGE_SIZE);
}
static struct pool_cache pagecache;
/* called with the object locked */
struct vm_page *
uvm_pagealloc_strat(struct uvm_object *uobj, voff_t off, struct vm_anon *anon,
@ -122,14 +142,14 @@ uvm_pagealloc_strat(struct uvm_object *uobj, voff_t off, struct vm_anon *anon,
{
struct vm_page *pg;
pg = kmem_zalloc(sizeof(struct vm_page), KM_SLEEP);
pg = pool_cache_get(&pagecache, PR_WAITOK);
pg->offset = off;
pg->uobject = uobj;
pg->uanon = (void *)kmem_alloc(PAGE_SIZE, KM_SLEEP);
if (flags & UVM_PGA_ZERO)
memset(pg->uanon, 0, PAGE_SIZE);
pg->flags = PG_CLEAN|PG_BUSY|PG_FAKE;
if (flags & UVM_PGA_ZERO) {
uvm_pagezero(pg);
}
TAILQ_INSERT_TAIL(&uobj->memq, pg, listq.queue);
rb_tree_insert_node(&uobj->rb_tree, &pg->rb_node);
@ -155,8 +175,7 @@ uvm_pagefree(struct vm_page *pg)
uobj->uo_npages--;
rb_tree_remove_node(&uobj->rb_tree, &pg->rb_node);
TAILQ_REMOVE(&uobj->memq, pg, listq.queue);
kmem_free((void *)pg->uanon, PAGE_SIZE);
kmem_free(pg, sizeof(*pg));
pool_cache_put(&pagecache, pg);
}
void
@ -207,6 +226,9 @@ uvm_init(void)
callback_head_init(&kernel_map_store.vmk_reclaim_callback, IPL_VM);
kmem_map->pmap = pmap_kernel();
callback_head_init(&kmem_map_store.vmk_reclaim_callback, IPL_VM);
pool_cache_bootstrap(&pagecache, sizeof(struct vm_page), 0, 0, 0,
"page$", NULL, IPL_NONE, pgctor, pgdtor, NULL);
}
void