From: David Mosberger <davidm@napali.hpl.hp.com>
To: Linus Torvalds <torvalds@osdl.org>
Cc: "Luck, Tony" <tony.luck@intel.com>,
linux-ia64@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: pipe performance regression on ia64
Date: Tue, 18 Jan 2005 18:31:10 +0000 [thread overview]
Message-ID: <16877.21998.984277.551515@napali.hpl.hp.com> (raw)
In-Reply-To: <Pine.LNX.4.58.0501180951050.8178@ppc970.osdl.org>
>>>>> On Tue, 18 Jan 2005 10:11:26 -0800 (PST), Linus Torvalds <torvalds@osdl.org> 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:
- producer/consumer pinned to the same CPU
- producer/consumer pinned to different CPUs
- producer/consumer lefter under control of the scheduler
The first two would let us observe any changes in the actual pipe
code, whereas the 3rd case would tell us which case the scheduler is
leaning towards (or if it starts doing something real crazy, like
reschedule the tasks on different CPUs each time, we'd see a bandwith
lower than case 2 and that should ring alarm bells).
--david
next prev parent reply other threads:[~2005-01-18 18:31 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-01-18 17:41 pipe performance regression on ia64 Luck, Tony
2005-01-18 18:11 ` Linus Torvalds
2005-01-18 18:31 ` David Mosberger [this message]
2005-01-18 20:17 ` Linus Torvalds
2005-01-19 3:05 ` [Lmbench-users] " Larry McVoy
2005-01-19 3:20 ` Linus Torvalds
2005-01-19 3:24 ` Zou, Nanhai
2005-01-19 6:35 ` Luck, Tony
2005-01-19 9:23 ` Staelin, Carl
2005-01-19 16:40 ` Larry McVoy
2005-01-18 23:34 ` Nick Piggin
2005-01-19 5:11 ` David Mosberger
2005-01-19 12:43 ` Nick Piggin
2005-01-19 17:31 ` David Mosberger
2005-01-19 12:52 ` Ingo Molnar
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