Module Name: src
Committed By: hannken
Date: Mon Mar 26 16:28:08 UTC 2012
Modified Files:
src/sys/dev: vnd.c vndvar.h
Log Message:
When backed by a sparse file limit the number of pending requests.
Should fix PR #45829: "writing to vnd on sparse file blocks on pager_map"
where the pager_map gets exhausted by requests enqueued on a vnd
device and the device worker thread blocks on putpages() needing the map.
While here always sync the underlying vnode before calling biodone().
XXX: vnd should be converted to mutex/condvar.
To generate a diff of this commit:
cvs rdiff -u -r1.219 -r1.220 src/sys/dev/vnd.c
cvs rdiff -u -r1.31 -r1.32 src/sys/dev/vndvar.h
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/dev/vnd.c
diff -u src/sys/dev/vnd.c:1.219 src/sys/dev/vnd.c:1.220
--- src/sys/dev/vnd.c:1.219 Fri Oct 14 09:23:30 2011
+++ src/sys/dev/vnd.c Mon Mar 26 16:28:08 2012
@@ -1,4 +1,4 @@
-/* $NetBSD: vnd.c,v 1.219 2011/10/14 09:23:30 hannken Exp $ */
+/* $NetBSD: vnd.c,v 1.220 2012/03/26 16:28:08 hannken Exp $ */
/*-
* Copyright (c) 1996, 1997, 1998, 2008 The NetBSD Foundation, Inc.
@@ -91,7 +91,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: vnd.c,v 1.219 2011/10/14 09:23:30 hannken Exp $");
+__KERNEL_RCSID(0, "$NetBSD: vnd.c,v 1.220 2012/03/26 16:28:08 hannken Exp $");
#if defined(_KERNEL_OPT)
#include "opt_vnd.h"
@@ -156,6 +156,8 @@ struct vndxfer {
#define VNDLABELDEV(dev) \
(MAKEDISKDEV(major((dev)), vndunit((dev)), RAW_PART))
+#define VND_MAXPENDING(vnd) ((vnd)->sc_maxactive * 4)
+
/* called by main() at boot time */
void vndattach(int);
@@ -496,6 +498,13 @@ vndstrategy(struct buf *bp)
if (vnddebug & VDB_FOLLOW)
printf("vndstrategy(%p): unit %d\n", bp, unit);
#endif
+ if ((vnd->sc_flags & VNF_USE_VN_RDWR)) {
+ KASSERT(vnd->sc_pending >= 0 &&
+ vnd->sc_pending <= VND_MAXPENDING(vnd));
+ while (vnd->sc_pending == VND_MAXPENDING(vnd))
+ tsleep(&vnd->sc_pending, PRIBIO, "vndpc", 0);
+ vnd->sc_pending++;
+ }
bufq_put(vnd->sc_tab, bp);
wakeup(&vnd->sc_tab);
splx(s);
@@ -587,6 +596,12 @@ vndthread(void *arg)
tsleep(&vnd->sc_tab, PRIBIO, "vndbp", 0);
continue;
};
+ if ((vnd->sc_flags & VNF_USE_VN_RDWR)) {
+ KASSERT(vnd->sc_pending > 0 &&
+ vnd->sc_pending <= VND_MAXPENDING(vnd));
+ if (vnd->sc_pending-- == VND_MAXPENDING(vnd))
+ wakeup(&vnd->sc_pending);
+ }
splx(s);
flags = obp->b_flags;
#ifdef DEBUG
@@ -722,13 +737,9 @@ handle_with_rdwr(struct vnd_softc *vnd,
IO_ADV_ENCODE(POSIX_FADV_NOREUSE), vnd->sc_cred, &resid, NULL);
bp->b_resid = resid;
- /* Keep mapped pages below threshold. */
mutex_enter(vp->v_interlock);
- if (vp->v_uobj.uo_npages > 1024*1024 / PAGE_SIZE)
- (void) VOP_PUTPAGES(vp, 0, 0,
- PGO_ALLPAGES | PGO_CLEANIT | PGO_FREE | PGO_SYNCIO);
- else
- mutex_exit(vp->v_interlock);
+ (void) VOP_PUTPAGES(vp, 0, 0,
+ PGO_ALLPAGES | PGO_CLEANIT | PGO_FREE | PGO_SYNCIO);
/* We need to increase the number of outputs on the vnode if
* there was any write to it. */
Index: src/sys/dev/vndvar.h
diff -u src/sys/dev/vndvar.h:1.31 src/sys/dev/vndvar.h:1.32
--- src/sys/dev/vndvar.h:1.31 Wed Jun 29 09:12:42 2011
+++ src/sys/dev/vndvar.h Mon Mar 26 16:28:08 2012
@@ -1,4 +1,4 @@
-/* $NetBSD: vndvar.h,v 1.31 2011/06/29 09:12:42 hannken Exp $ */
+/* $NetBSD: vndvar.h,v 1.32 2012/03/26 16:28:08 hannken Exp $ */
/*-
* Copyright (c) 1996, 1997, 1998 The NetBSD Foundation, Inc.
@@ -113,6 +113,7 @@ struct vnd_softc {
kauth_cred_t sc_cred; /* credentials */
int sc_maxactive; /* max # of active requests */
struct bufq_state *sc_tab; /* transfer queue */
+ int sc_pending; /* number of pending transfers */
int sc_active; /* number of active transfers */
struct disk sc_dkdev; /* generic disk device info */
struct vndgeom sc_geom; /* virtual geometry */
