Re: xfs, 2.6.27=>.32 sync write 10 times slowdown [was: xfs, aacraid2.6.27 => 2.6.32 results in 6 times slowdown]

From: Eric Sandeen
Date: Thu Jun 10 2010 - 10:58:32 EST


Dave Chinner wrote:
> On Wed, Jun 09, 2010 at 11:11:53PM +0400, Michael Tokarev wrote:


>> The same is with -o osyncisosync (in .34). Actually,
>> osyncis[od]sync mount options does not change anything, not
>> in .32 nor in .34.
>
> I think only osyncisosync exists, and it doesn't do anything
> anymore.

Just to be pedantic, osyncisdsync "exists," but is deprecated and does
nothing to change defaults:

} else if (!strcmp(this_char, "osyncisdsync")) {
/* no-op, this is now the default */
cmn_err(CE_WARN,
"XFS: osyncisdsync is now the default, option is deprecated.");
}

huh, didn't realize that osyncisosync does nothing but set a flag that
is never tested other than to show mount options:

File Function Line
0 xfs_mount.h <global> 285 #define XFS_MOUNT_OSYNCISOSYNC (1ULL << 13)
1 linux-2.6/xfs_super.c xfs_parseargs 292 mp->m_flags |= XFS_MOUNT_OSYNCISOSYNC;
2 linux-2.6/xfs_super.c xfs_showargs 542 { XFS_MOUNT_OSYNCISOSYNC, "," MNTOPT_OSYNCISOSYNC },

Time to deprecate/remove that one too I guess?

-Eric

> Cheers,
>
> Dave.

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