Re: [GIT PULL] Ext3 latency fixes

Linus Torvalds
2009-04-04T18:12:52Z

On Sat, 4 Apr 2009, Jens Axboe wrote:
>
> > Also, I may be odd, but I really do think latency is more important than
> > throughput. When my disk has latencies in the sub-milliseconds, I simply
> > do not think it is _acceptable_ to have hickups that affect my workload in
> > human-visible terms.
>
> Not everyone has an Intel SSD.

The thing is, I know for a fact that the hickups were much worse _before_
I had the Intel SSD.

With the SSD, I have to work a lot more to get them. Back when I had
regular rotational disks, I definitely did not need to do any 2GB file
creation at all. Just standard "yum update" would make my mail reader
pause.

Yeah, it's just for a short time, but it's very annoying. One second is
quite noticeable when I type something, and it doesn't show up on the
screen ("What? My Nehalem cannot keep up with my _typing_?"). 2-3 seconds
it really feels bad. And by the time it takes 5+ seconds, I start moving
my mouse around just to see whether the computer crashed.

Linus