svn commit: r354850 - head/sys/vm
Doug Moore
dougm at FreeBSD.org
Tue Nov 19 08:06:32 UTC 2019
Author: dougm
Date: Tue Nov 19 08:06:31 2019
New Revision: 354850
URL: https://svnweb.freebsd.org/changeset/base/354850
Log:
Drop the extra argument from swp_pager_meta_ctl and have it do lookup
only. Rename it swp_pager_meta_lookup. Stop checking for obj->type
== swap there and assert it instead. Make the caller responsible for
the obj->type check.
Move the meta_ctl 'pop' functionality to swap_pager_unswapped, the
only place that uses it, and assume obj->type == swap there too.
Assisted by: ota_j.email.ne.jp
Reviewed by: kib
Tested by: pho
Differential Revision: https://reviews.freebsd.org/D22437
Modified:
head/sys/vm/swap_pager.c
Modified: head/sys/vm/swap_pager.c
==============================================================================
--- head/sys/vm/swap_pager.c Tue Nov 19 07:20:59 2019 (r354849)
+++ head/sys/vm/swap_pager.c Tue Nov 19 08:06:31 2019 (r354850)
@@ -321,8 +321,6 @@ swap_release_by_cred(vm_ooffset_t decr, struct ucred *
#endif
}
-#define SWM_POP 0x01 /* pop out */
-
static int swap_pager_full = 2; /* swap space exhaustion (task killing) */
static int swap_pager_almost_full = 1; /* swap space exhaustion (w/hysteresis)*/
static struct mtx swbuf_mtx; /* to sync nsw_wcount_async */
@@ -426,7 +424,7 @@ static void swp_pager_meta_free(vm_object_t, vm_pindex
static void swp_pager_meta_transfer(vm_object_t src, vm_object_t dst,
vm_pindex_t pindex, vm_pindex_t count);
static void swp_pager_meta_free_all(vm_object_t);
-static daddr_t swp_pager_meta_ctl(vm_object_t, vm_pindex_t, int);
+static daddr_t swp_pager_meta_lookup(vm_object_t, vm_pindex_t);
static void
swp_pager_init_freerange(daddr_t *start, daddr_t *num)
@@ -942,7 +940,10 @@ swp_pager_xfer_source(vm_object_t srcobject, vm_object
{
daddr_t dstaddr;
- if (swp_pager_meta_ctl(dstobject, pindex, 0) != SWAPBLK_NONE) {
+ KASSERT(srcobject->type == OBJT_SWAP,
+ ("%s: Srcobject not swappable", __func__));
+ if (dstobject->type == OBJT_SWAP &&
+ swp_pager_meta_lookup(dstobject, pindex) != SWAPBLK_NONE) {
/* Caller should destroy the source block. */
return (false);
}
@@ -1050,11 +1051,13 @@ swap_pager_haspage(vm_object_t object, vm_pindex_t pin
int i;
VM_OBJECT_ASSERT_LOCKED(object);
+ KASSERT(object->type == OBJT_SWAP,
+ ("%s: object not swappable", __func__));
/*
* do we have good backing store at the requested index ?
*/
- blk0 = swp_pager_meta_ctl(object, pindex, 0);
+ blk0 = swp_pager_meta_lookup(object, pindex);
if (blk0 == SWAPBLK_NONE) {
if (before)
*before = 0;
@@ -1070,7 +1073,7 @@ swap_pager_haspage(vm_object_t object, vm_pindex_t pin
for (i = 1; i < SWB_NPAGES; i++) {
if (i > pindex)
break;
- blk = swp_pager_meta_ctl(object, pindex - i, 0);
+ blk = swp_pager_meta_lookup(object, pindex - i);
if (blk != blk0 - i)
break;
}
@@ -1082,7 +1085,7 @@ swap_pager_haspage(vm_object_t object, vm_pindex_t pin
*/
if (after != NULL) {
for (i = 1; i < SWB_NPAGES; i++) {
- blk = swp_pager_meta_ctl(object, pindex + i, 0);
+ blk = swp_pager_meta_lookup(object, pindex + i);
if (blk != blk0 + i)
break;
}
@@ -1113,11 +1116,26 @@ swap_pager_haspage(vm_object_t object, vm_pindex_t pin
static void
swap_pager_unswapped(vm_page_t m)
{
- daddr_t srcaddr;
+ struct swblk *sb;
- srcaddr = swp_pager_meta_ctl(m->object, m->pindex, SWM_POP);
- if (srcaddr != SWAPBLK_NONE)
- swp_pager_freeswapspace(srcaddr, 1);
+ VM_OBJECT_ASSERT_WLOCKED(m->object);
+
+ /*
+ * The meta data only exists if the object is OBJT_SWAP
+ * and even then might not be allocated yet.
+ */
+ KASSERT(m->object->type == OBJT_SWAP,
+ ("Free object not swappable"));
+
+ sb = SWAP_PCTRIE_LOOKUP(&m->object->un_pager.swp.swp_blks,
+ rounddown(m->pindex, SWAP_META_PAGES));
+ if (sb == NULL)
+ return;
+ if (sb->d[m->pindex % SWAP_META_PAGES] == SWAPBLK_NONE)
+ return;
+ swp_pager_freeswapspace(sb->d[m->pindex % SWAP_META_PAGES], 1);
+ sb->d[m->pindex % SWAP_META_PAGES] = SWAPBLK_NONE;
+ swp_pager_free_empty_swblk(m->object, sb);
}
/*
@@ -1152,6 +1170,8 @@ swap_pager_getpages(vm_object_t object, vm_page_t *ma,
* and then this function incorrectly recreates those pages as
* read-behind pages in the current object.
*/
+ KASSERT(object->type == OBJT_SWAP,
+ ("%s: object not swappable", __func__));
if (!swap_pager_haspage(object, ma[0]->pindex, &maxbehind, &maxahead))
return (VM_PAGER_FAIL);
@@ -1211,7 +1231,7 @@ swap_pager_getpages(vm_object_t object, vm_page_t *ma,
vm_object_pip_add(object, count);
pindex = bm->pindex;
- blk = swp_pager_meta_ctl(object, pindex, 0);
+ blk = swp_pager_meta_lookup(object, pindex);
KASSERT(blk != SWAPBLK_NONE,
("no swap blocking containing %p(%jx)", object, (uintmax_t)pindex));
@@ -1688,6 +1708,8 @@ swp_pager_force_pagein(vm_object_t object, vm_pindex_t
KASSERT(npages > 0, ("%s: No pages", __func__));
KASSERT(npages <= MAXPHYS / PAGE_SIZE,
("%s: Too many pages: %d", __func__, npages));
+ KASSERT(object->type == OBJT_SWAP,
+ ("%s: Object not swappable", __func__));
vm_object_pip_add(object, npages);
vm_page_grab_pages(object, pindex, VM_ALLOC_NORMAL, ma, npages);
for (i = j = 0;; i++) {
@@ -1725,6 +1747,8 @@ swap_pager_swapoff_object(struct swdevt *sp, vm_object
daddr_t blk, n_blks, s_blk;
int i;
+ KASSERT(object->type == OBJT_SWAP,
+ ("%s: Object not swappable", __func__));
n_blks = 0;
for (pi = 0; (sb = SWAP_PCTRIE_LOOKUP_GE(
&object->un_pager.swp.swp_blks, pi)) != NULL; ) {
@@ -2123,39 +2147,26 @@ swp_pager_meta_free_all(vm_object_t object)
* When acting on a busy resident page and paging is in progress, we
* have to wait until paging is complete but otherwise can act on the
* busy page.
- *
- * SWM_POP remove from meta data but do not free it
*/
static daddr_t
-swp_pager_meta_ctl(vm_object_t object, vm_pindex_t pindex, int flags)
+swp_pager_meta_lookup(vm_object_t object, vm_pindex_t pindex)
{
struct swblk *sb;
- daddr_t r1;
- if ((flags & SWM_POP) != 0)
- VM_OBJECT_ASSERT_WLOCKED(object);
- else
- VM_OBJECT_ASSERT_LOCKED(object);
+ VM_OBJECT_ASSERT_LOCKED(object);
/*
* The meta data only exists if the object is OBJT_SWAP
* and even then might not be allocated yet.
*/
- if (object->type != OBJT_SWAP)
- return (SWAPBLK_NONE);
+ KASSERT(object->type == OBJT_SWAP,
+ ("Lookup object not swappable"));
sb = SWAP_PCTRIE_LOOKUP(&object->un_pager.swp.swp_blks,
rounddown(pindex, SWAP_META_PAGES));
if (sb == NULL)
return (SWAPBLK_NONE);
- r1 = sb->d[pindex % SWAP_META_PAGES];
- if (r1 == SWAPBLK_NONE)
- return (SWAPBLK_NONE);
- if ((flags & SWM_POP) != 0) {
- sb->d[pindex % SWAP_META_PAGES] = SWAPBLK_NONE;
- swp_pager_free_empty_swblk(object, sb);
- }
- return (r1);
+ return (sb->d[pindex % SWAP_META_PAGES]);
}
/*
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