On 03.04.2011 23:05, Dio Brando wrote: > # time strace -S time -tt > /usr/src/grub2-1.98+20100804/debian/grub-common/usr/sbin/grub-probe > --device /dev/sda1 --target=fs_uuid -v > /tmp/probe_strace 2>&1 > > real 5m2.368s > user 0m0.080s > sys 0m0.092s > > log attached at this email. Looks like the time comes from calling BLKFLSBUF. Attached patch makes BLKFLSBUF only on write.
-- Regards Vladimir 'φ-coder/phcoder' Serbinenko
=== modified file 'grub-core/kern/emu/hostdisk.c'
--- grub-core/kern/emu/hostdisk.c 2011-04-03 13:45:20 +0000
+++ grub-core/kern/emu/hostdisk.c 2011-04-03 21:21:00 +0000
@@ -629,11 +629,14 @@
#ifdef O_LARGEFILE
flags |= O_LARGEFILE;
#endif
+
#ifdef O_SYNC
- flags |= O_SYNC;
+ if ((flags & O_ACCMODE) == O_WRONLY || (flags & O_ACCMODE) == O_RDWR)
+ flags |= O_SYNC;
#endif
#ifdef O_FSYNC
- flags |= O_FSYNC;
+ if ((flags & O_ACCMODE) == O_WRONLY || (flags & O_ACCMODE) == O_RDWR)
+ flags |= O_FSYNC;
#endif
#ifdef O_BINARY
flags |= O_BINARY;
@@ -664,7 +667,17 @@
{
free (data->dev);
if (data->fd != -1)
- close (data->fd);
+ {
+#ifdef __linux__
+ if (data->access_mode == O_RDWR || data->access_mode == O_WRONLY)
+ {
+ fsync (data->fd);
+ ioctl (data->fd, BLKFLSBUF, 0);
+ }
+#endif
+
+ close (data->fd);
+ }
/* Open the partition. */
grub_dprintf ("hostdisk", "opening the device `%s' in open_device()\n", dev);
@@ -675,10 +688,6 @@
return -1;
}
- /* Flush the buffer cache to the physical disk.
- XXX: This also empties the buffer cache. */
- ioctl (fd, BLKFLSBUF, 0);
-
data->dev = xstrdup (dev);
data->access_mode = (flags & O_ACCMODE);
data->fd = fd;
@@ -716,7 +725,16 @@
{
free (data->dev);
if (data->fd != -1)
- close (data->fd);
+ {
+#ifdef __linux__
+ if (data->access_mode == O_RDWR || data->access_mode == O_WRONLY)
+ {
+ fsync (data->fd);
+ ioctl (data->fd, BLKFLSBUF, 0);
+ }
+#endif
+ close (data->fd);
+ }
fd = open (map[disk->id].device, flags);
if (fd >= 0)
@@ -932,7 +950,16 @@
free (data->dev);
if (data->fd != -1)
- close (data->fd);
+ {
+#ifdef __linux__
+ if (data->access_mode == O_RDWR || data->access_mode == O_WRONLY)
+ {
+ fsync (data->fd);
+ ioctl (data->fd, BLKFLSBUF, 0);
+ }
+#endif
+ close (data->fd);
+ }
free (data);
}
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