> On Wed, 19 Jan 2005 23:43:45 +1100, Nick Piggin <[EMAIL PROTECTED]> said:
Nick> Oh that's quite true. A bad score on SMP on the pipe benchmark
Nick> does not mean anything is broken.
Nick> And IMO, probably many (most?) lmbench tests should be run
Nick> with all processes bound to t
On Tue, Jan 18, 2005 at 12:17:11PM -0800, Linus Torvalds wrote:
>
>
> On Tue, 18 Jan 2005, David Mosberger wrote:
> >
> > > On Tue, 18 Jan 2005 10:11:26 -0800 (PST), Linus Torvalds <[EMAIL
> > > PROTECTED]> said:
> >
> > Linus> I don't know how to make the benchmark look repeatable an
* Linus Torvalds <[EMAIL PROTECTED]> wrote:
> The "wake_up_sync()" hack only helps for the special case where we
> know the writer is going to write more. Of course, we could make the
> pipe code use that "synchronous" write unconditionally, and benchmarks
> would look better, but I suspect it wo
David Mosberger wrote:
On Wed, 19 Jan 2005 10:34:30 +1100, Nick Piggin <[EMAIL PROTECTED]> said:
Nick> David I remember you reporting a pipe bandwidth regression,
Nick> and I had a patch for it, but that hurt other workloads, so I
Nick> don't think we ever really got anywhere. I've recently
Mailing List
Subject: RE: [Lmbench-users] Re: pipe performance regression on ia64
>Maybe lmbench could add a feature that bw_pipe will fork CPU number of
>children to measure the average throughput.
>
>This will give a much reasonable result when running bw_pipe on a SMP
>Box, at l
>Maybe lmbench could add a feature that bw_pipe will fork CPU
>number of children to measure the average throughput.
>
>This will give a much reasonable result when running bw_pipe
>on a SMP Box, at least for Linux.
bw_pipe (along with most/all of the lmbench tools already has
a "-P" argument t
> On Wed, 19 Jan 2005 10:34:30 +1100, Nick Piggin <[EMAIL PROTECTED]> said:
Nick> David I remember you reporting a pipe bandwidth regression,
Nick> and I had a patch for it, but that hurt other workloads, so I
Nick> don't think we ever really got anywhere. I've recently begun
Nick> hav
; Kernel Mailing
List
> Subject: Re: [Lmbench-users] Re: pipe performance regression on ia64
>
> I'm very unthrilled with the idea of adding stuff to the release
benchmark
> which is OS specific. That said, there is nothing to say that you
can't
> grab the benchmark and
On Tue, 18 Jan 2005, Larry McVoy wrote:
>
> I'm very unthrilled with the idea of adding stuff to the release benchmark
> which is OS specific. That said, there is nothing to say that you can't
> grab the benchmark and tweak your own test case in there to prove or
> disprove your theory.
Hmm..
It would be good if you copied me directly since I don't read the kernel
list anymore (I'd love to but don't have the bandwidth) and I rarely read
the lmbench list. But only if you want to drag me into it, of course.
Carl and I both work on LMbench but not very actively. I had really
hoped that
Linus Torvalds wrote:
On Tue, 18 Jan 2005, Luck, Tony wrote:
David Mosberger:
So, when we run bw_pipe on a low load SMP machine, the kernel running in
a way load balancer always trying to spread out 2 processes while the
wake_up_interruptible_sync() is always trying to draw them back into
1 cpu.
Li
On Tue, 18 Jan 2005, David Mosberger wrote:
>
> > On Tue, 18 Jan 2005 10:11:26 -0800 (PST), Linus Torvalds <[EMAIL
> > PROTECTED]> said:
>
> Linus> I don't know how to make the benchmark look repeatable and
> Linus> good, though. The CPU affinity thing may be the right thing.
>
>
> On Tue, 18 Jan 2005 10:11:26 -0800 (PST), Linus Torvalds <[EMAIL
> PROTECTED]> said:
Linus> I don't know how to make the benchmark look repeatable and
Linus> good, though. The CPU affinity thing may be the right thing.
Perhaps it should be split up into three cases:
- pro
On Tue, 18 Jan 2005, Luck, Tony wrote:
> David Mosberger:
> >
> >So, when we run bw_pipe on a low load SMP machine, the kernel running in
> >a way load balancer always trying to spread out 2 processes while the
> >wake_up_interruptible_sync() is always trying to draw them back into
> >1 cpu.
> >
David Mosberger pointed out to me that 2.6.11-rc1 kernel scores
very badly on ia64 in lmbench pipe throughput test (bw_pipe) compared
with earlier kernels.
Nanhai Zou looked into this, and found that the performance loss
began with Linus' patch to speed up pipe performance by allocating
a circular
15 matches
Mail list logo
