Author: markj
Date: Fri Nov 13 02:16:08 2015
New Revision: 290741
URL: https://svnweb.freebsd.org/changeset/base/290741
Log:
MFC r287235:
Remove weighted page handling from vm_page_advise().
Modified:
stable/10/sys/sys/pcpu.h
stable/10/sys/vm/vm_page.c
Directory Properties:
stable/10/ (props changed)
Modified: stable/10/sys/sys/pcpu.h
==============================================================================
--- stable/10/sys/sys/pcpu.h Fri Nov 13 01:47:56 2015 (r290740)
+++ stable/10/sys/sys/pcpu.h Fri Nov 13 02:16:08 2015 (r290741)
@@ -162,7 +162,7 @@ struct pcpu {
long pc_cp_time[CPUSTATES]; /* statclock ticks */
struct device *pc_device;
void *pc_netisr; /* netisr SWI cookie */
- int pc_dnweight; /* vm_page_dontneed() */
+ int pc_unused1; /* unused field */
int pc_domain; /* Memory domain. */
struct rm_queue pc_rm_queue; /* rmlock list of trackers */
uintptr_t pc_dynamic; /* Dynamic per-cpu data area */
Modified: stable/10/sys/vm/vm_page.c
==============================================================================
--- stable/10/sys/vm/vm_page.c Fri Nov 13 01:47:56 2015 (r290740)
+++ stable/10/sys/vm/vm_page.c Fri Nov 13 02:16:08 2015 (r290741)
@@ -2430,19 +2430,26 @@ _vm_page_deactivate(vm_page_t m, int ath
struct vm_pagequeue *pq;
int queue;
- vm_page_lock_assert(m, MA_OWNED);
+ vm_page_assert_locked(m);
/*
- * Ignore if already inactive.
+ * Ignore if the page is already inactive, unless it is unlikely to be
+ * reactivated.
*/
- if ((queue = m->queue) == PQ_INACTIVE)
+ if ((queue = m->queue) == PQ_INACTIVE && !athead)
return;
if (m->wire_count == 0 && (m->oflags & VPO_UNMANAGED) == 0) {
- if (queue != PQ_NONE)
- vm_page_dequeue(m);
- m->flags &= ~PG_WINATCFLS;
pq = &vm_phys_domain(m)->vmd_pagequeues[PQ_INACTIVE];
- vm_pagequeue_lock(pq);
+ /* Avoid multiple acquisitions of the inactive queue lock. */
+ if (queue == PQ_INACTIVE) {
+ vm_pagequeue_lock(pq);
+ vm_page_dequeue_locked(m);
+ } else {
+ if (queue != PQ_NONE)
+ vm_page_dequeue(m);
+ m->flags &= ~PG_WINATCFLS;
+ vm_pagequeue_lock(pq);
+ }
m->queue = PQ_INACTIVE;
if (athead)
TAILQ_INSERT_HEAD(&pq->pq_pl, m, plinks.q);
@@ -2618,34 +2625,18 @@ vm_page_cache(vm_page_t m)
/*
* vm_page_advise
*
- * Cache, deactivate, or do nothing as appropriate. This routine
- * is used by madvise().
- *
- * Generally speaking we want to move the page into the cache so
- * it gets reused quickly. However, this can result in a silly syndrome
- * due to the page recycling too quickly. Small objects will not be
- * fully cached. On the other hand, if we move the page to the inactive
- * queue we wind up with a problem whereby very large objects
- * unnecessarily blow away our inactive and cache queues.
- *
- * The solution is to move the pages based on a fixed weighting. We
- * either leave them alone, deactivate them, or move them to the cache,
- * where moving them to the cache has the highest weighting.
- * By forcing some pages into other queues we eventually force the
- * system to balance the queues, potentially recovering other unrelated
- * space from active. The idea is to not force this to happen too
- * often.
+ * Deactivate or do nothing, as appropriate. This routine is used
+ * by madvise() and vop_stdadvise().
*
* The object and page must be locked.
*/
void
vm_page_advise(vm_page_t m, int advice)
{
- int dnw, head;
vm_page_assert_locked(m);
VM_OBJECT_ASSERT_WLOCKED(m->object);
- if (advice == MADV_FREE) {
+ if (advice == MADV_FREE)
/*
* Mark the page clean. This will allow the page to be freed
* up by the system. However, such pages are often reused
@@ -2656,24 +2647,12 @@ vm_page_advise(vm_page_t m, int advice)
* nor do we try to put it in the cache (which would cause a
* page fault on reuse).
*
- * But we do make the page is freeable as we can without
+ * But we do make the page as freeable as we can without
* actually taking the step of unmapping it.
*/
m->dirty = 0;
- m->act_count = 0;
- } else if (advice != MADV_DONTNEED)
+ else if (advice != MADV_DONTNEED)
return;
- dnw = PCPU_GET(dnweight);
- PCPU_INC(dnweight);
-
- /*
- * Occasionally leave the page alone.
- */
- if ((dnw & 0x01F0) == 0 || m->queue == PQ_INACTIVE) {
- if (m->act_count >= ACT_INIT)
- --m->act_count;
- return;
- }
/*
* Clear any references to the page. Otherwise, the page daemon will
@@ -2684,20 +2663,12 @@ vm_page_advise(vm_page_t m, int advice)
if (advice != MADV_FREE && m->dirty == 0 && pmap_is_modified(m))
vm_page_dirty(m);
- if (m->dirty || (dnw & 0x0070) == 0) {
- /*
- * Deactivate the page 3 times out of 32.
- */
- head = 0;
- } else {
- /*
- * Cache the page 28 times out of every 32. Note that
- * the page is deactivated instead of cached, but placed
- * at the head of the queue instead of the tail.
- */
- head = 1;
- }
- _vm_page_deactivate(m, head);
+ /*
+ * Place clean pages at the head of the inactive queue rather than the
+ * tail, thus defeating the queue's LRU operation and ensuring that the
+ * page will be reused quickly.
+ */
+ _vm_page_deactivate(m, m->dirty == 0);
}
/*
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