Module Name: src
Committed By: ad
Date: Sun Dec 1 17:02:50 UTC 2019
Modified Files:
src/sys/uvm: uvm_anon.c
Log Message:
Free pages in batch instead of taking uvm_pageqlock for each one.
To generate a diff of this commit:
cvs rdiff -u -r1.65 -r1.66 src/sys/uvm/uvm_anon.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/uvm/uvm_anon.c
diff -u src/sys/uvm/uvm_anon.c:1.65 src/sys/uvm/uvm_anon.c:1.66
--- src/sys/uvm/uvm_anon.c:1.65 Sun Dec 1 14:40:31 2019
+++ src/sys/uvm/uvm_anon.c Sun Dec 1 17:02:50 2019
@@ -1,4 +1,4 @@
-/* $NetBSD: uvm_anon.c,v 1.65 2019/12/01 14:40:31 ad Exp $ */
+/* $NetBSD: uvm_anon.c,v 1.66 2019/12/01 17:02:50 ad Exp $ */
/*
* Copyright (c) 1997 Charles D. Cranor and Washington University.
@@ -30,7 +30,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: uvm_anon.c,v 1.65 2019/12/01 14:40:31 ad Exp $");
+__KERNEL_RCSID(0, "$NetBSD: uvm_anon.c,v 1.66 2019/12/01 17:02:50 ad Exp $");
#include "opt_uvmhist.h"
@@ -94,7 +94,7 @@ uvm_analloc(void)
}
/*
- * uvm_anon_dispose: free any resident page or swap resources of anon.
+ * uvm_anon_dispose: break loans and remove pmap mapping
*
* => anon must be removed from the amap (if anon was in an amap).
* => amap must be locked; we may drop and re-acquire the lock here.
@@ -110,17 +110,6 @@ uvm_anon_dispose(struct vm_anon *anon)
KASSERT(mutex_owned(anon->an_lock));
/*
- * If there is a resident page and it is loaned, then anon may not
- * own it. Call out to uvm_anon_lockloanpg() to identify and lock
- * the real owner of the page.
- */
-
- if (pg && pg->loan_count) {
- KASSERT(anon->an_lock != NULL);
- pg = uvm_anon_lockloanpg(anon);
- }
-
- /*
* Dispose the page, if it is resident.
*/
@@ -128,6 +117,16 @@ uvm_anon_dispose(struct vm_anon *anon)
KASSERT(anon->an_lock != NULL);
/*
+ * If there is a resident page and it is loaned, then anon
+ * may not own it. Call out to uvm_anon_lockloanpg() to
+ * identify and lock the real owner of the page.
+ */
+
+ if (pg->loan_count) {
+ pg = uvm_anon_lockloanpg(anon);
+ }
+
+ /*
* If the page is owned by a UVM object (now locked),
* then kill the loan on the page rather than free it,
* and release the object lock.
@@ -160,12 +159,6 @@ uvm_anon_dispose(struct vm_anon *anon)
mutex_obj_hold(anon->an_lock);
return false;
}
- mutex_enter(&uvm_pageqlock);
- uvm_pagefree(pg);
- mutex_exit(&uvm_pageqlock);
- UVMHIST_LOG(maphist, "anon 0x%#jx, page 0x%#jx: "
- "freed now!", (uintptr_t)anon, (uintptr_t)pg,
- 0, 0);
}
}
@@ -177,12 +170,6 @@ uvm_anon_dispose(struct vm_anon *anon)
}
#endif
- /*
- * Free any swap resources, leave a page replacement hint.
- */
-
- uvm_anon_dropswap(anon);
- uvmpdpol_anfree(anon);
UVMHIST_LOG(maphist,"<- done!",0,0,0,0);
return true;
}
@@ -196,6 +183,10 @@ void
uvm_anon_free(struct vm_anon *anon)
{
+#if defined(VMSWAP)
+ /* Free any dangling swap slot. */
+ uvm_anon_dropswap(anon);
+#endif
KASSERT(anon->an_ref == 0);
KASSERT(anon->an_lock == NULL);
KASSERT(anon->an_page == NULL);
@@ -208,15 +199,23 @@ uvm_anon_free(struct vm_anon *anon)
/*
* uvm_anon_freelst: free a linked list of anon structures.
*
- * => anon must be locked, we will unlock it.
+ * => amap must be locked, we will unlock it.
*/
void
uvm_anon_freelst(struct vm_amap *amap, struct vm_anon *anonlst)
{
struct vm_anon *anon;
struct vm_anon **anonp = &anonlst;
+ struct vm_page *pg;
KASSERT(mutex_owned(amap->am_lock));
+
+ if (anonlst == NULL) {
+ amap_unlock(amap);
+ return;
+ }
+
+ /* Break loans and hardware mappings. Defer release of busy pages. */
while ((anon = *anonp) != NULL) {
if (!uvm_anon_dispose(anon)) {
/* Do not free this anon. */
@@ -227,8 +226,22 @@ uvm_anon_freelst(struct vm_amap *amap, s
anonp = &anon->an_link;
}
}
+
+ /* Free pages and leave a page replacement hint. */
+ mutex_enter(&uvm_pageqlock);
+ for (anon = anonlst; anon != NULL; anon = anon->an_link) {
+ UVMHIST_LOG(maphist, "anon 0x%#jx, page 0x%#jx: "
+ "releasing now!", (uintptr_t)anon,
+ (uintptr_t)anon->an_page, 0, 0);
+ if ((pg = anon->an_page) != NULL) {
+ uvm_pagefree(pg);
+ }
+ uvmpdpol_anfree(anon);
+ }
+ mutex_exit(&uvm_pageqlock);
amap_unlock(amap);
+ /* Free swap space, pages and vm_anon. */
while (anonlst) {
anon = anonlst->an_link;
/* Note: clears an_ref as well. */
