From: William Lee Irwin III <wli@holomorphy.com>
To: Zwane Mwaikambo <zwane@linuxpower.ca>
Cc: Andrew Morton <akpm@digeo.com>,
davem@redhat.com, andrea@suse.de, davidsen@tmr.com,
haveblue@us.ibm.com, habanero@us.ibm.com, mbligh@aracnet.com,
linux-kernel@vger.kernel.org
Subject: Re: userspace irq balancer
Date: Mon, 26 May 2003 19:44:19 -0700 [thread overview]
Message-ID: <20030527024419.GF8978@holomorphy.com> (raw)
In-Reply-To: <Pine.LNX.4.50.0305262212070.2265-100000@montezuma.mastecende.com>
On Mon, 26 May 2003, William Lee Irwin III wrote:
>> The number of interrupt sources on a system ends up scaling this up to
>> numerous IO-APIC RTE reprograms and ioapic_lock acquisitions per-second
>> (granted, with a 5s timeout between reprogramming storms) where it
>> competes against IO-APIC interrupt acknowledgements.
>> Making the lock per- IO-APIC would at least put a bound on the number
>> of competitors mutually interfering with each other, but a tighter
>> bound on the amount of work than NR_IRQS would be more useful than that.
On Mon, May 26, 2003 at 10:15:23PM -0400, Zwane Mwaikambo wrote:
> Ok there are 16 IOAPICs on an 8quad, but really if we start banging on
> that lock someone is doing way too much hardware access...
It's done to acknowledge every interrupt. Also, there is additional
cost associated with bouncing the lock's cacheline.
-- wli
next prev parent reply other threads:[~2003-05-27 2:31 UTC|newest]
Thread overview: 76+ messages / expand[flat|nested] mbox.gz Atom feed top
2003-05-21 21:43 userspace irq balancer Nakajima, Jun
2003-05-22 0:29 ` Gerrit Huizenga
2003-05-22 1:28 ` Martin J. Bligh
2003-05-22 1:44 ` Gerrit Huizenga
2003-05-22 2:03 ` William Lee Irwin III
2003-05-22 2:04 ` William Lee Irwin III
2003-05-22 2:12 ` Zwane Mwaikambo
2003-05-22 3:57 ` Martin J. Bligh
2003-05-22 17:24 ` Bill Davidsen
2003-05-22 22:44 ` David S. Miller
2003-05-26 22:24 ` Andrea Arcangeli
2003-05-26 23:26 ` Andrew Morton
2003-05-26 23:34 ` Andrea Arcangeli
2003-05-26 23:43 ` David S. Miller
[not found] ` <20030527000639.GA3767@dualathlon.random>
2003-05-27 0:15 ` David S. Miller
2003-05-27 0:41 ` Andrea Arcangeli
2003-05-27 0:48 ` David S. Miller
2003-05-27 1:09 ` Andrea Arcangeli
2003-05-27 1:13 ` David S. Miller
2003-05-27 1:26 ` Andrea Arcangeli
2003-05-27 6:11 ` David S. Miller
2003-05-27 11:53 ` Andrea Arcangeli
2003-05-27 22:04 ` David S. Miller
2003-05-27 22:27 ` Andrea Arcangeli
2003-05-27 23:55 ` David S. Miller
2003-06-13 6:22 ` David S. Miller
2003-06-13 18:23 ` Andrea Arcangeli
2003-05-27 1:16 ` Dave Jones
2003-05-27 1:17 ` David S. Miller
2003-05-27 9:07 ` Arjan van de Ven
2003-05-27 9:10 ` David S. Miller
2003-05-27 1:28 ` Andrea Arcangeli
2003-05-27 1:53 ` William Lee Irwin III
2003-05-27 1:59 ` Andrew Morton
2003-05-27 2:10 ` William Lee Irwin III
2003-05-27 2:15 ` Zwane Mwaikambo
2003-05-27 2:44 ` William Lee Irwin III [this message]
2003-05-27 2:45 ` Zwane Mwaikambo
2003-05-27 4:22 ` William Lee Irwin III
2003-05-27 2:15 ` Andrea Arcangeli
2003-05-27 2:14 ` Andrea Arcangeli
2003-05-27 2:26 ` William Lee Irwin III
2003-05-27 1:17 ` Andrea Arcangeli
2003-05-27 1:20 ` David S. Miller
2003-05-27 1:33 ` Andrea Arcangeli
2003-05-22 14:18 ` James Cleverdon
2003-05-22 14:43 ` William Lee Irwin III
2003-05-22 15:30 ` James Cleverdon
2003-05-22 15:45 ` William Lee Irwin III
-- strict thread matches above, loose matches on Subject: below --
2003-05-24 1:10 Nakajima, Jun
2003-05-21 16:31 James Bottomley
2003-05-21 20:16 ` Arjan van de Ven
2003-05-20 15:41 Nakajima, Jun
2003-05-21 13:54 ` James Cleverdon
2003-05-21 22:56 ` Zwane Mwaikambo
[not found] <200305191314.06216.pbadari@us.ibm.com>
2003-05-19 22:07 ` Dave Hansen
2003-05-19 22:11 ` Arjan van de Ven
2003-05-19 22:22 ` Dave Hansen
2003-05-20 3:25 ` David S. Miller
2003-05-20 3:46 ` William Lee Irwin III
2003-05-20 5:03 ` Dave Hansen
2003-05-20 5:53 ` Martin J. Bligh
2003-05-20 6:13 ` David S. Miller
2003-05-20 6:36 ` Dave Hansen
2003-05-20 6:40 ` David S. Miller
2003-05-20 14:07 ` Andrew Theurer
2003-05-20 14:21 ` Jeff Garzik
2003-05-20 14:35 ` Andrew Theurer
[not found] ` <20030520.163833.104040023.davem@redhat.com>
2003-05-21 14:58 ` Martin J. Bligh
2003-05-21 22:55 ` David S. Miller
2003-05-21 11:00 ` Kai Bankett
2003-05-20 14:01 ` Martin J. Bligh
2003-05-20 9:00 ` Arjan van de Ven
2003-05-20 9:14 ` William Lee Irwin III
2003-05-20 9:17 ` Andrew Morton
[not found] ` <20030520.172230.102567463.davem@redhat.com>
2003-05-21 14:27 ` James Cleverdon
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