Module Name: src
Committed By: rmind
Date: Mon Apr 18 15:53:04 UTC 2011
Modified Files:
src/sys/miscfs/genfs: genfs_io.c
src/sys/miscfs/syncfs: sync_subr.c syncfs.h
src/sys/sys: vnode.h
Log Message:
G/C unused speedup_syncer() mechanism and thus simplify some code.
Update some comments to reflect the reality. No actual changes to
the (used) syncer logic.
OK ad@
To generate a diff of this commit:
cvs rdiff -u -r1.46 -r1.47 src/sys/miscfs/genfs/genfs_io.c
cvs rdiff -u -r1.43 -r1.44 src/sys/miscfs/syncfs/sync_subr.c
cvs rdiff -u -r1.11 -r1.12 src/sys/miscfs/syncfs/syncfs.h
cvs rdiff -u -r1.227 -r1.228 src/sys/sys/vnode.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/miscfs/genfs/genfs_io.c
diff -u src/sys/miscfs/genfs/genfs_io.c:1.46 src/sys/miscfs/genfs/genfs_io.c:1.47
--- src/sys/miscfs/genfs/genfs_io.c:1.46 Mon Dec 6 10:22:43 2010
+++ src/sys/miscfs/genfs/genfs_io.c Mon Apr 18 15:53:04 2011
@@ -1,4 +1,4 @@
-/* $NetBSD: genfs_io.c,v 1.46 2010/12/06 10:22:43 uebayasi Exp $ */
+/* $NetBSD: genfs_io.c,v 1.47 2011/04/18 15:53:04 rmind Exp $ */
/*
* Copyright (c) 1982, 1986, 1989, 1993
@@ -31,7 +31,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: genfs_io.c,v 1.46 2010/12/06 10:22:43 uebayasi Exp $");
+__KERNEL_RCSID(0, "$NetBSD: genfs_io.c,v 1.47 2011/04/18 15:53:04 rmind Exp $");
#include <sys/param.h>
#include <sys/systm.h>
@@ -52,6 +52,7 @@
#include <miscfs/genfs/genfs.h>
#include <miscfs/genfs/genfs_node.h>
#include <miscfs/specfs/specdev.h>
+#include <miscfs/syncfs/syncfs.h>
#include <uvm/uvm.h>
#include <uvm/uvm_pager.h>
Index: src/sys/miscfs/syncfs/sync_subr.c
diff -u src/sys/miscfs/syncfs/sync_subr.c:1.43 src/sys/miscfs/syncfs/sync_subr.c:1.44
--- src/sys/miscfs/syncfs/sync_subr.c:1.43 Wed Jul 21 17:52:12 2010
+++ src/sys/miscfs/syncfs/sync_subr.c Mon Apr 18 15:53:04 2011
@@ -1,4 +1,4 @@
-/* $NetBSD: sync_subr.c,v 1.43 2010/07/21 17:52:12 hannken Exp $ */
+/* $NetBSD: sync_subr.c,v 1.44 2011/04/18 15:53:04 rmind Exp $ */
/*-
* Copyright (c) 2009 The NetBSD Foundation, Inc.
@@ -60,8 +60,37 @@
* SUCH DAMAGE.
*/
+/*
+ * The filesystem synchronizer mechanism - syncer.
+ *
+ * It is useful to delay writes of file data and filesystem metadata for
+ * a certain amount of time so that quickly created and deleted files need
+ * not waste disk bandwidth being created and removed. To implement this,
+ * vnodes are appended to a "workitem" queue.
+ *
+ * Most pending metadata should not wait for more than ten seconds. Thus,
+ * mounted on block devices are delayed only about a half the time that file
+ * data is delayed. Similarly, directory updates are more critical, so are
+ * only delayed about a third the time that file data is delayed.
+ *
+ * There are SYNCER_MAXDELAY queues that are processed in a round-robin
+ * manner at a rate of one each second (driven off the filesystem syner
+ * thread). The syncer_delayno variable indicates the next queue that is
+ * to be processed. Items that need to be processed soon are placed in
+ * this queue:
+ *
+ * syncer_workitem_pending[syncer_delayno]
+ *
+ * A delay of e.g. fifteen seconds is done by placing the request fifteen
+ * entries later in the queue:
+ *
+ * syncer_workitem_pending[(syncer_delayno + 15) & syncer_mask]
+ *
+ * Flag VI_ONWORKLST indicates that vnode is added into the queue.
+ */
+
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: sync_subr.c,v 1.43 2010/07/21 17:52:12 hannken Exp $");
+__KERNEL_RCSID(0, "$NetBSD: sync_subr.c,v 1.44 2011/04/18 15:53:04 rmind Exp $");
#include <sys/param.h>
#include <sys/systm.h>
@@ -78,7 +107,10 @@
#include <miscfs/genfs/genfs.h>
#include <miscfs/syncfs/syncfs.h>
+typedef TAILQ_HEAD(synclist, vnode) synclist_t;
+
static void vn_syncer_add1(struct vnode *, int);
+static void sysctl_vfs_syncfs_setup(struct sysctllog **);
/*
* Defines and variables for the syncer process.
@@ -90,19 +122,12 @@
time_t metadelay = 10; /* time to delay syncing metadata */
time_t lockdelay = 1; /* time to delay if locking fails */
-kmutex_t syncer_mutex; /* used to freeze syncer, long term */
-static kmutex_t syncer_data_lock; /* short term lock on data structures */
+kmutex_t syncer_mutex; /* used to freeze syncer, long term */
+static kmutex_t syncer_data_lock; /* short term lock on data structs */
-static int rushjob; /* number of slots to run ASAP */
-static kcondvar_t syncer_cv; /* cv for rushjob */
-static int stat_rush_requests; /* number of times I/O speeded up */
-
-static int syncer_delayno = 0;
-static long syncer_last;
-static struct synclist *syncer_workitem_pending;
-struct lwp *updateproc = NULL;
-
-static void sysctl_vfs_syncfs_setup(struct sysctllog **);
+static int syncer_delayno = 0;
+static long syncer_last;
+static synclist_t * syncer_workitem_pending;
void
vn_initialize_syncerd(void)
@@ -121,57 +146,27 @@
mutex_init(&syncer_mutex, MUTEX_DEFAULT, IPL_NONE);
mutex_init(&syncer_data_lock, MUTEX_DEFAULT, IPL_NONE);
- cv_init(&syncer_cv, "syncer");
}
/*
- * The workitem queue.
- *
- * It is useful to delay writes of file data and filesystem metadata
- * for tens of seconds so that quickly created and deleted files need
- * not waste disk bandwidth being created and removed. To realize this,
- * we append vnodes to a "workitem" queue. When running with a soft
- * updates implementation, most pending metadata dependencies should
- * not wait for more than a few seconds. Thus, mounted on block devices
- * are delayed only about a half the time that file data is delayed.
- * Similarly, directory updates are more critical, so are only delayed
- * about a third the time that file data is delayed. Thus, there are
- * SYNCER_MAXDELAY queues that are processed round-robin at a rate of
- * one each second (driven off the filesystem syner process). The
- * syncer_delayno variable indicates the next queue that is to be processed.
- * Items that need to be processed soon are placed in this queue:
- *
- * syncer_workitem_pending[syncer_delayno]
- *
- * A delay of fifteen seconds is done by placing the request fifteen
- * entries later in the queue:
- *
- * syncer_workitem_pending[(syncer_delayno + 15) & syncer_mask]
- *
- */
-
-/*
* Add an item to the syncer work queue.
*/
static void
vn_syncer_add1(struct vnode *vp, int delayx)
{
- struct synclist *slp;
+ synclist_t *slp;
KASSERT(mutex_owned(&syncer_data_lock));
if (vp->v_iflag & VI_ONWORKLST) {
+ /*
+ * Remove in order to adjust the position of the vnode.
+ * Note: called from sched_sync(), which will not hold
+ * interlock, therefore we cannot modify v_iflag here.
+ */
slp = &syncer_workitem_pending[vp->v_synclist_slot];
TAILQ_REMOVE(slp, vp, v_synclist);
} else {
- /*
- * We must not modify v_iflag if the vnode
- * is already on a synclist: sched_sync()
- * calls this routine while holding only
- * syncer_data_lock in order to adjust the
- * position of the vnode. syncer_data_lock
- * does not protect v_iflag.
- */
KASSERT(mutex_owned(&vp->v_interlock));
vp->v_iflag |= VI_ONWORKLST;
}
@@ -201,18 +196,16 @@
void
vn_syncer_remove_from_worklist(struct vnode *vp)
{
- struct synclist *slp;
+ synclist_t *slp;
KASSERT(mutex_owned(&vp->v_interlock));
mutex_enter(&syncer_data_lock);
-
if (vp->v_iflag & VI_ONWORKLST) {
vp->v_iflag &= ~VI_ONWORKLST;
slp = &syncer_workitem_pending[vp->v_synclist_slot];
TAILQ_REMOVE(slp, vp, v_synclist);
}
-
mutex_exit(&syncer_data_lock);
}
@@ -220,15 +213,13 @@
* System filesystem synchronizer daemon.
*/
void
-sched_sync(void *v)
+sched_sync(void *arg)
{
- struct synclist *slp;
+ synclist_t *slp;
struct vnode *vp;
time_t starttime;
bool synced;
- updateproc = curlwp;
-
for (;;) {
mutex_enter(&syncer_mutex);
mutex_enter(&syncer_data_lock);
@@ -292,66 +283,25 @@
mutex_exit(&syncer_mutex);
/*
- * Wait until there are more workitems to process.
+ * If it has taken us less than a second to process the
+ * current work, then wait. Otherwise start right over
+ * again. We can still lose time if any single round
+ * takes more than two seconds, but it does not really
+ * matter as we are just trying to generally pace the
+ * filesystem activity.
*/
- if (rushjob > 0) {
- /*
- * The variable rushjob allows the kernel to speed
- * up the processing of the filesystem syncer
- * process. A rushjob value of N tells the
- * filesystem syncer to process the next N seconds
- * worth of work on its queue ASAP. Currently
- * rushjob is used by the soft update code to
- * speed up the filesystem syncer process when the
- * incore state is getting so far ahead of the
- * disk that the kernel memory pool is being
- * threatened with exhaustion.
- */
- rushjob--;
- } else {
- /*
- * If it has taken us less than a second to
- * process the current work, then wait. Otherwise
- * start right over again. We can still lose time
- * if any single round takes more than two
- * seconds, but it does not really matter as we
- * are just trying to generally pace the
- * filesystem activity.
- */
- if (time_second == starttime)
- cv_timedwait(&syncer_cv, &syncer_data_lock, hz);
+ if (time_second == starttime) {
+ kpause("syncer", false, hz, &syncer_data_lock);
}
mutex_exit(&syncer_data_lock);
}
}
-/*
- * Request the syncer daemon to speed up its work.
- * We never push it to speed up more than half of its
- * normal turn time, otherwise it could take over the CPU.
- */
-int
-speedup_syncer(void)
-{
-
- mutex_enter(&syncer_data_lock);
- if (rushjob >= syncdelay / 2) {
- mutex_exit(&syncer_data_lock);
- return (0);
- }
- rushjob++;
- cv_signal(&syncer_cv);
- stat_rush_requests += 1;
- mutex_exit(&syncer_data_lock);
-
- return (1);
-}
-
static void
sysctl_vfs_syncfs_setup(struct sysctllog **clog)
{
const struct sysctlnode *rnode, *cnode;
-
+
sysctl_createv(clog, 0, NULL, &rnode,
CTLFLAG_PERMANENT,
CTLTYPE_NODE, "vfs", NULL,
Index: src/sys/miscfs/syncfs/syncfs.h
diff -u src/sys/miscfs/syncfs/syncfs.h:1.11 src/sys/miscfs/syncfs/syncfs.h:1.12
--- src/sys/miscfs/syncfs/syncfs.h:1.11 Fri Feb 9 21:55:36 2007
+++ src/sys/miscfs/syncfs/syncfs.h Mon Apr 18 15:53:04 2011
@@ -1,4 +1,4 @@
-/* $NetBSD: syncfs.h,v 1.11 2007/02/09 21:55:36 ad Exp $ */
+/* $NetBSD: syncfs.h,v 1.12 2011/04/18 15:53:04 rmind Exp $ */
/*
* Copyright 1997 Marshall Kirk McKusick. All Rights Reserved.
@@ -47,17 +47,21 @@
#define sync_islocked genfs_noislocked
#define sync_putpages genfs_null_putpages
-void sched_sync(void *);
-void vn_initialize_syncerd(void);
-int vfs_allocate_syncvnode(struct mount *);
-void vfs_deallocate_syncvnode(struct mount *);
+void sched_sync(void *);
+void vn_initialize_syncerd(void);
+int vfs_allocate_syncvnode(struct mount *);
+void vfs_deallocate_syncvnode(struct mount *);
extern int (**sync_vnodeop_p)(void *);
-#define SYNCER_MAXDELAY 32
+#define SYNCER_MAXDELAY 32
-extern int syncer_maxdelay; /* maximum delay time */
-extern kmutex_t syncer_mutex; /* lock to freeze syncer during unmount */
-TAILQ_HEAD(synclist, vnode);
+extern int syncer_maxdelay;
+extern kmutex_t syncer_mutex;
+
+extern time_t syncdelay;
+extern time_t filedelay;
+extern time_t dirdelay;
+extern time_t metadelay;
#endif /* _MISCFS_SYNCFS_SYNCFS_H_ */
Index: src/sys/sys/vnode.h
diff -u src/sys/sys/vnode.h:1.227 src/sys/sys/vnode.h:1.228
--- src/sys/sys/vnode.h:1.227 Sun Apr 3 01:19:36 2011
+++ src/sys/sys/vnode.h Mon Apr 18 15:53:04 2011
@@ -1,4 +1,4 @@
-/* $NetBSD: vnode.h,v 1.227 2011/04/03 01:19:36 rmind Exp $ */
+/* $NetBSD: vnode.h,v 1.228 2011/04/18 15:53:04 rmind Exp $ */
/*-
* Copyright (c) 2008 The NetBSD Foundation, Inc.
@@ -398,10 +398,6 @@
extern struct vnode *rootvnode; /* root (i.e. "/") vnode */
extern int desiredvnodes; /* number of vnodes desired */
extern u_int numvnodes; /* current number of vnodes */
-extern time_t syncdelay; /* max time to delay syncing data */
-extern time_t filedelay; /* time to delay syncing files */
-extern time_t dirdelay; /* time to delay syncing directories */
-extern time_t metadelay; /* time to delay syncing metadata */
/*
* Macro/function to check for client cache inconsistency w.r.t. leasing.
