Re: scsi vs ide performance on fsync's

Andre Hedrick
2001-03-02T19:28:28Z

Okay I now have to create TCQ for ATA becasue I am not going to lose again
now that I am winning ;-)

On Fri, 2 Mar 2001, Chris Mason wrote:

>
>
> On Friday, March 02, 2001 12:39:01 PM -0600 Steve Lord <lord@sgi.com> wrote:
>
> [ file_fsync syncs all dirty buffers on the FS ]
> >
> > So it looks like fsync is going to cost more for bigger devices. Given the
> > O_SYNC changes Stephen Tweedie did, couldnt fsync look more like this:
> >
> > down(&inode->i_sem);
> > filemap_fdatasync(ip->i_mapping);
> > fsync_inode_buffers(ip);
> > filemap_fdatawait(ip->i_mapping);
> > up(&inode->i_sem);
> >
>
> reiserfs might need to trigger a commit on fsync, so the fs specific fsync
> op needs to be called. But, you should not need to call file_fsync in the
> XFS fsync call (check out ext2's)
>
> For why ide is beating scsi in this benchmark...make sure tagged queueing
> is on (or increase the queue length?). For the xlog.c test posted, I would
> expect scsi to get faster than ide as the size of the write increases.
>
> -chris
>
> -
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Andre Hedrick
Linux ATA Development
ASL Kernel Development
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