[src/trunk]: src/sys/kern - move disk cache flushing code into a separate fun...

[yamt <yamt%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/cd51ae6b52e4
branches:  trunk
changeset: 771746:cd51ae6b52e4
user:      yamt <yamt%NetBSD.org@localhost>
date:      Fri Dec 02 12:38:59 2011 +0000

description:
- move disk cache flushing code into a separate function.
- more verbose output if vfs.wapbl.verbose_commit >= 2.
  namely, time taken for each DIOCCACHESYNC calls.
        wapbl_flush: 1322826000.785245900 this transaction = 546304 bytes
        wapbl_cache_sync: 1: dev 0x0 0.017572724
        wapbl_cache_sync: 2: dev 0x0 0.007199825
        wapbl_flush: 1322826011.860771302 this transaction = 431104 bytes
        wapbl_cache_sync: 1: dev 0x0 0.019469753
        wapbl_cache_sync: 2: dev 0x0 0.009473410
        wapbl_flush: 1322829266.489154342 this transaction = 187904 bytes
        wapbl_cache_sync: 1: dev 0x4 0.022270180
        wapbl_cache_sync: 2: dev 0x4 0.030749402
- fix a comment.

diffstat:

 sys/kern/vfs_wapbl.c |  67 ++++++++++++++++++++++++++++++++++-----------------
 1 files changed, 44 insertions(+), 23 deletions(-)

diffs (108 lines):

diff -r 7aa5a811cce4 -r cd51ae6b52e4 sys/kern/vfs_wapbl.c
--- a/sys/kern/vfs_wapbl.c      Fri Dec 02 12:33:12 2011 +0000
+++ b/sys/kern/vfs_wapbl.c      Fri Dec 02 12:38:59 2011 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: vfs_wapbl.c,v 1.47 2011/09/01 09:03:43 christos Exp $  */
+/*     $NetBSD: vfs_wapbl.c,v 1.48 2011/12/02 12:38:59 yamt Exp $      */
 
 /*-
  * Copyright (c) 2003, 2008, 2009 The NetBSD Foundation, Inc.
@@ -36,7 +36,7 @@
 #define WAPBL_INTERNAL
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: vfs_wapbl.c,v 1.47 2011/09/01 09:03:43 christos Exp $");
+__KERNEL_RCSID(0, "$NetBSD: vfs_wapbl.c,v 1.48 2011/12/02 12:38:59 yamt Exp $");
 
 #include <sys/param.h>
 #include <sys/bitops.h>
@@ -1903,11 +1903,49 @@
 }
 
 /*
+ * wapbl_cache_sync: issue DIOCCACHESYNC
+ */
+static int
+wapbl_cache_sync(struct wapbl *wl, const char *msg)
+{
+       const bool verbose = wapbl_verbose_commit >= 2;
+       struct bintime start_time;
+       int force = 1;
+       int error;
+
+       if (!wapbl_flush_disk_cache) {
+               return 0;
+       }
+       if (verbose) {
+               bintime(&start_time);
+       }
+       error = VOP_IOCTL(wl->wl_devvp, DIOCCACHESYNC, &force,
+           FWRITE, FSCRED);
+       if (error) {
+               WAPBL_PRINTF(WAPBL_PRINT_ERROR,
+                   ("wapbl_cache_sync: DIOCCACHESYNC on dev 0x%x "
+                   "returned %d\n", wl->wl_devvp->v_rdev, error));
+       }
+       if (verbose) {
+               struct bintime d;
+               struct timespec ts;
+
+               bintime(&d);
+               bintime_sub(&d, &start_time);
+               bintime2timespec(&d, &ts);
+               printf("wapbl_cache_sync: %s: dev 0x%jx %ju.%09lu\n",
+                   msg, (uintmax_t)wl->wl_devvp->v_rdev,
+                   (uintmax_t)ts.tv_sec, ts.tv_nsec);
+       }
+       return error;
+}
+
+/*
  * Perform commit operation
  *
  * Note that generation number incrementation needs to
  * be protected against racing with other invocations
- * of wapbl_commit.  This is ok since this routine
+ * of wapbl_write_commit.  This is ok since this routine
  * is only invoked from wapbl_flush
  */
 static int
@@ -1916,19 +1954,10 @@
        struct wapbl_wc_header *wc = wl->wl_wc_header;
        struct timespec ts;
        int error;
-       int force = 1;
        daddr_t pbn;
 
-       if (wapbl_flush_disk_cache) {
-               /* XXX Calc checksum here, instead we do this for now */
-               error = VOP_IOCTL(wl->wl_devvp, DIOCCACHESYNC, &force,
-                   FWRITE, FSCRED);
-               if (error) {
-                       WAPBL_PRINTF(WAPBL_PRINT_ERROR,
-                           ("wapbl_write_commit: DIOCCACHESYNC on dev 0x%x "
-                           "returned %d\n", wl->wl_devvp->v_rdev, error));
-               }
-       }
+       /* XXX Calc checksum here, instead we do this for now */
+       wapbl_cache_sync(wl, "1");
 
        wc->wc_head = head;
        wc->wc_tail = tail;
@@ -1955,15 +1984,7 @@
        if (error)
                return error;
 
-       if (wapbl_flush_disk_cache) {
-               error = VOP_IOCTL(wl->wl_devvp, DIOCCACHESYNC, &force,
-                   FWRITE, FSCRED);
-               if (error) {
-                       WAPBL_PRINTF(WAPBL_PRINT_ERROR,
-                           ("wapbl_write_commit: DIOCCACHESYNC on dev 0x%x "
-                           "returned %d\n", wl->wl_devvp->v_rdev, error));
-               }
-       }
+       wapbl_cache_sync(wl, "2");
 
        /*
         * If the generation number was zero, write it out a second time.