Re: [PATCH] ide write barrier support

[Jens Axboe <axboe@suse.de>]

On Tue, Oct 14 2003, Greg Stark wrote:
> 
> Jens Axboe <axboe@suse.de> writes:
> 
> > Hi,
> > 
> > Forward ported and tested today (with the dummy ext3 patch included),
> > works for me. Some todo's left, but I thought I'd send it out to gauge
> > interest. TODO:
> 
> 
> Is there a user-space interface planned for this? 

I don't have one planned.

> One possibility may be just to hang it off fsync(2) so fsync doesn't
> return until until all the buffers it flushed are actually synced to
> disk. That's its documented semantics anyways.

Makes sense, indeed.

> There's also the case of files opened with O_SYNC. Would inserting a
> write barrier after every write to such a file destroy performance?

If it's mainly sequential io, then no it won't destroy performance. It
will be lower than without the cache flush of course.

-- 
Jens Axboe