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Index: head/sys/vm/vm_pageout.c
===================================================================
--- head/sys/vm/vm_pageout.c
+++ head/sys/vm/vm_pageout.c
@@ -1352,7 +1352,7 @@
* target.
*/
static int
-vm_pageout_scan_inactive(struct vm_domain *vmd, int pass, int shortage,
+vm_pageout_scan_inactive(struct vm_domain *vmd, int shortage,
int *addl_shortage)
{
struct scan_state ss;
@@ -1366,25 +1366,6 @@
bool obj_locked;
/*
- * If we need to reclaim memory ask kernel caches to return
- * some. We rate limit to avoid thrashing.
- */
- if (vmd == VM_DOMAIN(0) && pass > 0 &&
- (time_uptime - lowmem_uptime) >= lowmem_period) {
- /*
- * Decrease registered cache sizes.
- */
- SDT_PROBE0(vm, , , vm__lowmem_scan);
- EVENTHANDLER_INVOKE(vm_lowmem, VM_LOW_PAGES);
- /*
- * We do this explicitly after the caches have been
- * drained above.
- */
- uma_reclaim();
- lowmem_uptime = time_uptime;
- }
-
- /*
* The addl_page_shortage is an estimate of the number of temporarily
* stuck pages in the inactive queue. In other words, the
* number of pages from the inactive count that should be
@@ -1393,16 +1374,13 @@
addl_page_shortage = 0;
/*
- * Calculate the number of pages that we want to free. This number
- * can be negative if many pages are freed between the wakeup call to
- * the page daemon and this calculation.
+ * vmd_pageout_deficit counts the number of pages requested in
+ * allocations that failed because of a free page shortage. We assume
+ * that the allocations will be reattempted and thus include the deficit
+ * in our scan target.
*/
- if (pass > 0) {
- deficit = atomic_readandclear_int(&vmd->vmd_pageout_deficit);
- page_shortage = shortage + deficit;
- } else
- page_shortage = deficit = 0;
- starting_page_shortage = page_shortage;
+ deficit = atomic_readandclear_int(&vmd->vmd_pageout_deficit);
+ starting_page_shortage = page_shortage = shortage + deficit;
mtx = NULL;
obj_locked = false;
@@ -1638,8 +1616,7 @@
/*
* Reclaim pages by swapping out idle processes, if configured to do so.
*/
- if (pass > 0)
- vm_swapout_run_idle();
+ vm_swapout_run_idle();
/*
* See the description of addl_page_shortage above.
@@ -1870,15 +1847,35 @@
}
static void
+vm_pageout_lowmem(struct vm_domain *vmd)
+{
+
+ if (vmd == VM_DOMAIN(0) &&
+ time_uptime - lowmem_uptime >= lowmem_period) {
+ /*
+ * Decrease registered cache sizes.
+ */
+ SDT_PROBE0(vm, , , vm__lowmem_scan);
+ EVENTHANDLER_INVOKE(vm_lowmem, VM_LOW_PAGES);
+
+ /*
+ * We do this explicitly after the caches have been
+ * drained above.
+ */
+ uma_reclaim();
+ lowmem_uptime = time_uptime;
+ }
+}
+
+static void
vm_pageout_worker(void *arg)
{
struct vm_domain *vmd;
- int addl_shortage, domain, pass, shortage;
+ int addl_shortage, domain, shortage;
bool target_met;
domain = (uintptr_t)arg;
vmd = VM_DOMAIN(domain);
- pass = 0;
shortage = 0;
target_met = true;
@@ -1896,6 +1893,7 @@
*/
while (TRUE) {
vm_domain_pageout_lock(vmd);
+
/*
* We need to clear wanted before we check the limits. This
* prevents races with wakers who will check wanted after they
@@ -1908,12 +1906,12 @@
*/
if (vm_paging_needed(vmd, vmd->vmd_free_count)) {
/*
- * Yes, the scan failed to free enough pages. If
- * we have performed a level >= 1 (page reclamation)
- * scan, then sleep a bit and try again.
+ * Yes. If the scan failed to produce enough free
+ * pages, sleep uninterruptibly for some time in the
+ * hope that the laundry thread will clean some pages.
*/
vm_domain_pageout_unlock(vmd);
- if (pass > 1)
+ if (!target_met)
pause("pwait", hz / VM_INACT_SCAN_RATE);
} else {
/*
@@ -1934,10 +1932,12 @@
* this interval, and scan the inactive queue.
*/
shortage = pidctrl_daemon(&vmd->vmd_pid, vmd->vmd_free_count);
- if (shortage > 0 && pass == 0)
- pass = 1;
- target_met = vm_pageout_scan_inactive(vmd, pass, shortage,
- &addl_shortage);
+ if (shortage > 0) {
+ vm_pageout_lowmem(vmd);
+ target_met = vm_pageout_scan_inactive(vmd, shortage,
+ &addl_shortage);
+ } else
+ addl_shortage = 0;
/*
* Scan the active queue. A positive value for shortage
@@ -1946,13 +1946,6 @@
*/
shortage = vm_pageout_active_target(vmd) + addl_shortage;
vm_pageout_scan_active(vmd, shortage);
-
- /*
- * If the target was not met we must increase the pass to
- * more aggressively reclaim.
- */
- if (!target_met)
- pass++;
}
}

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