Re: Perforamnce comparison between 2.3.8 and 2.2.10
Chuck Lever (cel@monkey.org)
Mon, 28 Jun 1999 21:05:07 -0400 (EDT)
On Mon, 28 Jun 1999, Rudolf Leitgeb wrote:
> On 28-Jun-99 Andrea Arcangeli wrote:
> > On Mon, 28 Jun 1999, Chuck Lever wrote:
> >
> >>i also believe that a multithreaded page cache for file data won't help
> >>much if the file system is still serialized :)
>
> If the fs is single threaded, I assume that it's protected by some form
> of lock, and every process that waits for I/O will sleep, i.e. not accumulate
> CPU time. The parallel kernel compiles did not only take longer, they also spent
> more time in the CPU. Even if the fs code was protected by a spin lock, this
> would only show up in the system time, not in the user time ...
>
> Did I miss anything ?
the global kernel lock spins, but doesn't sleep. that explains the
difference in system CPU utilization, i think.
- Chuck Lever
--
corporate: <chuckl@netscape.com>
personal: <chucklever@netscape.net> or <cel@monkey.org>
The Linux Scalability project:
http://www.citi.umich.edu/projects/linux-scalability/
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.rutgers.edu
Please read the FAQ at http://www.tux.org/lkml/