Re: Linux 2.6.29

From: Linus Torvalds
Date: Wed Mar 25 2009 - 14:30:32 EST




On Wed, 25 Mar 2009, David Rees wrote:
>
> Your Intel SSD will write streaming data 2-4 times faster than your
> typical disk

Don't even bother with streaming data. The problem is _never_ streaming
data.

Even a suck-ass laptop drive can write streaming data fast enough that
people don't care. The problem is invariably that writes from different
sources (much of it being metadata) interact and cause seeking.

> and can be an order of magnitude faster when it comes to small, random
> writes.

Umm. More like two orders of magnitude or more.

Random writes on a disk (even a fast one) tends to be in the hundreds of
kilobytes per second. Have you worked with an Intel SSD? It does tens of
MB/s on pure random writes.

The problem really is gone with an SSD.

And please realize that the problem for me was never 30-second stalls. For
me, a 3-second stall is unacceptable. It's just very annoying.

Linus
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