Acquire the page lock around all remaining calls to vm_page_free() on

managed pages that didn't already have that lock held.  (Freeing an
unmanaged page, such as the various pmaps use, doesn't require the page
lock.)

This allows a change in vm_page_remove()'s locking requirements.  It now
expects the page lock to be held instead of the page queues lock.
Consequently, the page queues lock is no longer required at all by callers
to vm_page_rename().

Discussed with: kib

2 files changed, 4 insertions, 0 deletions

diff --git a/sys/kern/kern_exec.c b/sys/kern/kern_exec.c
index bb92972..0ec9817 100644
--- a/sys/kern/kern_exec.c
+++ b/sys/kern/kern_exec.c
@@ -949,9 +949,11 @@ exec_map_first_page(imgp)
 		ma[0] = vm_page_lookup(object, 0);
 		if ((rv != VM_PAGER_OK) || (ma[0] == NULL)) {
 			if (ma[0]) {
+				vm_page_lock(ma[0]);
 				vm_page_lock_queues();
 				vm_page_free(ma[0]);
 				vm_page_unlock_queues();
+				vm_page_unlock(ma[0]);
 			}
 			VM_OBJECT_UNLOCK(object);
 			return (EIO);
diff --git a/sys/kern/subr_uio.c b/sys/kern/subr_uio.c
index 725b1a8..783a8d6 100644
--- a/sys/kern/subr_uio.c
+++ b/sys/kern/subr_uio.c
@@ -104,9 +104,11 @@ retry:
 	if ((user_pg = vm_page_lookup(uobject, upindex)) != NULL) {
 		if (vm_page_sleep_if_busy(user_pg, TRUE, "vm_pgmoveco"))
 			goto retry;
+		vm_page_lock(user_pg);
 		vm_page_lock_queues();
 		pmap_remove_all(user_pg);
 		vm_page_free(user_pg);
+		vm_page_unlock(user_pg);
 	} else {
 		/*
 		 * Even if a physical page does not exist in the