Author: alc
Date: Wed Dec 29 20:35:36 2010
New Revision: 216807
URL: http://svn.freebsd.org/changeset/base/216807
Log:
There is no point in vm_contig_launder{,_page}() flushing held pages,
instead skip over them. As long as a page is held, it can't be reclaimed by
contigmalloc(M_WAITOK). Moreover, a held page may be undergoing
modification, e.g., vmapbuf(), so even if the hold were released before the
completion of contigmalloc(), the page might have to be flushed again.
MFC after: 3 weeks
Modified:
head/sys/vm/vm_contig.c
Modified: head/sys/vm/vm_contig.c
==============================================================================
--- head/sys/vm/vm_contig.c Wed Dec 29 19:39:51 2010 (r216806)
+++ head/sys/vm/vm_contig.c Wed Dec 29 20:35:36 2010 (r216807)
@@ -100,7 +100,7 @@ vm_contig_launder_page(vm_page_t m, vm_p
vm_page_lock_assert(m, MA_OWNED);
object = m->object;
if (!VM_OBJECT_TRYLOCK(object) &&
- !vm_pageout_fallback_object_lock(m, next)) {
+ (!vm_pageout_fallback_object_lock(m, next) || m->hold_count != 0)) {
vm_page_unlock(m);
VM_OBJECT_UNLOCK(object);
return (EAGAIN);
@@ -111,7 +111,7 @@ vm_contig_launder_page(vm_page_t m, vm_p
return (EBUSY);
}
vm_page_test_dirty(m);
- if (m->dirty == 0 && m->hold_count == 0)
+ if (m->dirty == 0)
pmap_remove_all(m);
if (m->dirty != 0) {
vm_page_unlock(m);
@@ -146,8 +146,7 @@ vm_contig_launder_page(vm_page_t m, vm_p
return (0);
}
} else {
- if (m->hold_count == 0)
- vm_page_cache(m);
+ vm_page_cache(m);
vm_page_unlock(m);
}
VM_OBJECT_UNLOCK(object);
@@ -171,7 +170,7 @@ vm_contig_launder(int queue, vm_paddr_t
if (pa < low || pa + PAGE_SIZE > high)
continue;
- if (!vm_pageout_page_lock(m, &next)) {
+ if (!vm_pageout_page_lock(m, &next) || m->hold_count != 0) {
vm_page_unlock(m);
continue;
}
_______________________________________________
svn-src-all@freebsd.org mailing list
http://lists.freebsd.org/mailman/listinfo/svn-src-all
To unsubscribe, send any mail to "svn-src-all-unsubscr...@freebsd.org"
