Re: File writes with O_SYNC slow

[Stephen C. Tweedie]

Hi,

On Wed, Apr 19, 2000 at 11:55:04AM -0400, Karl JH Millar wrote:
> 
> I've noticed that file writes with O_SYNC are very much slower than they should
> be.

How fast do you think they should be?

If you are doing small appends, then O_SYNC is _guaranteed_ to be dead
slow.  Ever write involves updating the data, updating the mapping tree,
and flushing the whole lot synchronously to disk.  That's two seeks per
write.

--Stephen