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

[Eric Sandeen]

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.