From fb0b76eb8f86155cb811c2039085009d89da54d2 Mon Sep 17 00:00:00 2001 From: kib Date: Fri, 4 Dec 2015 09:09:19 +0000 Subject: MFC r291379: Move the comment about resident pages preventing vnode from leaving active list, into the header comment for vdrop(). --- sys/kern/vfs_subr.c | 16 +++++++++++----- 1 file changed, 11 insertions(+), 5 deletions(-) (limited to 'sys/kern') diff --git a/sys/kern/vfs_subr.c b/sys/kern/vfs_subr.c index b5f5b42..2df1e25 100644 --- a/sys/kern/vfs_subr.c +++ b/sys/kern/vfs_subr.c @@ -2425,6 +2425,10 @@ vdrop(struct vnode *vp) * Drop the hold count of the vnode. If this is the last reference to * the vnode we place it on the free list unless it has been vgone'd * (marked VI_DOOMED) in which case we will free it. + * + * Because the vnode vm object keeps a hold reference on the vnode if + * there is at least one resident non-cached page, the vnode cannot + * leave the active list without the page cleanup done. */ void vdropl(struct vnode *vp) @@ -2540,11 +2544,13 @@ vinactive(struct vnode *vp, struct thread *td) VI_UNLOCK(vp); /* * Before moving off the active list, we must be sure that any - * modified pages are on the vnode's dirty list since these will - * no longer be checked once the vnode is on the inactive list. - * Because the vnode vm object keeps a hold reference on the vnode - * if there is at least one resident non-cached page, the vnode - * cannot leave the active list without the page cleanup done. + * modified pages are converted into the vnode's dirty + * buffers, since these will no longer be checked once the + * vnode is on the inactive list. + * + * The write-out of the dirty pages is asynchronous. At the + * point that VOP_INACTIVE() is called, there could still be + * pending I/O and dirty pages in the object. */ obj = vp->v_object; if (obj != NULL && (obj->flags & OBJ_MIGHTBEDIRTY) != 0) { -- cgit v1.1