Roughly half of a typical pmap_mincore() implementation is machine-

independent code.  Move this code into mincore(), and eliminate the
page queues lock from pmap_mincore().

Push down the page queues lock into pmap_clear_modify(),
pmap_clear_reference(), and pmap_is_modified().  Assert that these
functions are never passed an unmanaged page.

Eliminate an inaccurate comment from powerpc/powerpc/mmu_if.m:
Contrary to what the comment says, pmap_mincore() is not simply an
optimization.  Without a complete pmap_mincore() implementation,
mincore() cannot return either MINCORE_MODIFIED or MINCORE_REFERENCED
because only the pmap can provide this information.

Eliminate the page queues lock from vfs_setdirty_locked_object(),
vm_pageout_clean(), vm_object_page_collect_flush(), and
vm_object_page_clean().  Generally speaking, these are all accesses
to the page's dirty field, which are synchronized by the containing
vm object's lock.

Reduce the scope of the page queues lock in vm_object_madvise() and
vm_page_dontneed().

Reviewed by:	kib (an earlier version)

1 files changed, 0 insertions, 6 deletions

diff --git a/sys/vm/vm_pageout.c b/sys/vm/vm_pageout.c
index fde456f..3158a7d 100644
--- a/sys/vm/vm_pageout.c
+++ b/sys/vm/vm_pageout.c
@@ -391,17 +391,14 @@ more:
 			break;
 		}
 		vm_page_lock(p);
-		vm_page_lock_queues();
 		vm_page_test_dirty(p);
 		if (p->dirty == 0 ||
 		    p->queue != PQ_INACTIVE ||
 		    p->hold_count != 0) {	/* may be undergoing I/O */
 			vm_page_unlock(p);
-			vm_page_unlock_queues();
 			ib = 0;
 			break;
 		}
-		vm_page_unlock_queues();
 		vm_page_unlock(p);
 		mc[--page_base] = p;
 		++pageout_count;
@@ -424,16 +421,13 @@ more:
 			break;
 		}
 		vm_page_lock(p);
-		vm_page_lock_queues();
 		vm_page_test_dirty(p);
 		if (p->dirty == 0 ||
 		    p->queue != PQ_INACTIVE ||
 		    p->hold_count != 0) {	/* may be undergoing I/O */
-			vm_page_unlock_queues();
 			vm_page_unlock(p);
 			break;
 		}
-		vm_page_unlock_queues();
 		vm_page_unlock(p);
 		mc[page_base + pageout_count] = p;
 		++pageout_count;