[src/trunk]: src/sys/ufs/ffs i/o optimization for wapbl flush - only sync sup...

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

details:   https://anonhg.NetBSD.org/src/rev/90f23bb8f7fa
branches:  trunk
changeset: 347944:90f23bb8f7fa
user:      jdolecek <jdolecek%NetBSD.org@localhost>
date:      Sat Sep 24 20:59:51 2016 +0000

description:
i/o optimization for wapbl flush - only sync superblock and cgs when
they were actually changed

diffstat:

 sys/ufs/ffs/ffs_wapbl.c |  16 ++++++++++------
 1 files changed, 10 insertions(+), 6 deletions(-)

diffs (44 lines):

diff -r 106dc00feba8 -r 90f23bb8f7fa sys/ufs/ffs/ffs_wapbl.c
--- a/sys/ufs/ffs/ffs_wapbl.c   Sat Sep 24 20:13:48 2016 +0000
+++ b/sys/ufs/ffs/ffs_wapbl.c   Sat Sep 24 20:59:51 2016 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: ffs_wapbl.c,v 1.30 2015/03/28 19:24:04 maxv Exp $      */
+/*     $NetBSD: ffs_wapbl.c,v 1.31 2016/09/24 20:59:51 jdolecek Exp $  */
 
 /*-
  * Copyright (c) 2003,2006,2008 The NetBSD Foundation, Inc.
@@ -30,7 +30,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: ffs_wapbl.c,v 1.30 2015/03/28 19:24:04 maxv Exp $");
+__KERNEL_RCSID(0, "$NetBSD: ffs_wapbl.c,v 1.31 2016/09/24 20:59:51 jdolecek Exp $");
 
 #define WAPBL_INTERNAL
 
@@ -174,6 +174,8 @@
        struct fs *fs = ump->um_fs;
        int i, error __diagused;
 
+       UFS_WAPBL_JLOCK_ASSERT(mp);
+
 #ifdef WAPBL_DEBUG_INODES
        ufs_wapbl_verify_inodes(mp, "ffs_wapbl_sync_metadata");
 #endif
@@ -187,10 +189,12 @@
                    FFS_DBTOFSB(fs, deallocblks[i]), dealloclens[i], -1);
        }
 
-       fs->fs_fmod = 0;
-       fs->fs_time = time_second;
-       error = ffs_cgupdate(ump, 0);
-       KASSERT(error == 0);
+       if (fs->fs_fmod != 0) {
+               fs->fs_fmod = 0;
+               fs->fs_time = time_second;
+               error = ffs_cgupdate(ump, 0);
+               KASSERT(error != 0);
+       }
 }
 
 void