Eliminate page queues locking from bufdone_finish() through the

following changes:

Rename vfs_page_set_valid() to vfs_page_set_validclean() to reflect
what this function actually does.  Suggested by: tegge

Introduce a new version of vfs_page_set_valid() that does no more than
what the function's name implies.  Specifically, it does not update
the page's dirty mask, and thus it does not require the page queues
lock to be held.

Update two of the three callers to the old vfs_page_set_valid() to
call vfs_page_set_validclean() instead because they actually require
the page's dirty mask to be cleared.

Introduce vm_page_set_valid().

Reviewed by:	tegge

2 files changed, 46 insertions, 0 deletions

diff --git a/sys/vm/vm_page.c b/sys/vm/vm_page.c
index 8befdd5..f0f9042 100644
--- a/sys/vm/vm_page.c
+++ b/sys/vm/vm_page.c
@@ -1852,6 +1852,51 @@ vm_page_bits(int base, int size)
 }
 
 /*
+ *	vm_page_set_valid:
+ *
+ *	Sets portions of a page valid.  The arguments are expected
+ *	to be DEV_BSIZE aligned but if they aren't the bitmap is inclusive
+ *	of any partial chunks touched by the range.  The invalid portion of
+ *	such chunks will be zeroed.
+ *
+ *	(base + size) must be less then or equal to PAGE_SIZE.
+ */
+void
+vm_page_set_valid(vm_page_t m, int base, int size)
+{
+	int endoff, frag;
+
+	VM_OBJECT_LOCK_ASSERT(m->object, MA_OWNED);
+	if (size == 0)	/* handle degenerate case */
+		return;
+
+	/*
+	 * If the base is not DEV_BSIZE aligned and the valid
+	 * bit is clear, we have to zero out a portion of the
+	 * first block.
+	 */
+	if ((frag = base & ~(DEV_BSIZE - 1)) != base &&
+	    (m->valid & (1 << (base >> DEV_BSHIFT))) == 0)
+		pmap_zero_page_area(m, frag, base - frag);
+
+	/*
+	 * If the ending offset is not DEV_BSIZE aligned and the 
+	 * valid bit is clear, we have to zero out a portion of
+	 * the last block.
+	 */
+	endoff = base + size;
+	if ((frag = endoff & ~(DEV_BSIZE - 1)) != endoff &&
+	    (m->valid & (1 << (endoff >> DEV_BSHIFT))) == 0)
+		pmap_zero_page_area(m, endoff,
+		    DEV_BSIZE - (endoff & (DEV_BSIZE - 1)));
+
+	/*
+	 * Set valid bits inclusive of any overlap.
+	 */
+	m->valid |= vm_page_bits(base, size);
+}
+
+/*
  *	vm_page_set_validclean:
  *
  *	Sets portions of a page valid and clean.  The arguments are expected
diff --git a/sys/vm/vm_page.h b/sys/vm/vm_page.h
index 7f996ea..8bbbaee 100644
--- a/sys/vm/vm_page.h
+++ b/sys/vm/vm_page.h
@@ -321,6 +321,7 @@ vm_page_t vm_page_lookup (vm_object_t, vm_pindex_t);
 void vm_page_remove (vm_page_t);
 void vm_page_rename (vm_page_t, vm_object_t, vm_pindex_t);
 void vm_page_requeue(vm_page_t m);
+void vm_page_set_valid(vm_page_t m, int base, int size);
 void vm_page_sleep(vm_page_t m, const char *msg);
 vm_page_t vm_page_splay(vm_pindex_t, vm_page_t);
 vm_offset_t vm_page_startup(vm_offset_t vaddr);