From: Nick Piggin <piggin@cyberone.com.au>
To: Jamie Lokier <jamie@shareable.org>
Cc: bill davidsen <davidsen@tmr.com>, linux-kernel@vger.kernel.org
Subject: Re: [CFT][RFC] HT scheduler
Date: Sun, 14 Dec 2003 20:40:51 +1100 [thread overview]
Message-ID: <3FDC3023.9030708@cyberone.com.au> (raw)
In-Reply-To: <20031214043245.GC21241@mail.shareable.org>
Jamie Lokier wrote:
>Nick Piggin wrote:
>
>>>Shared runqueues sound like a simplification to describe execution units
>>>which have shared resourses and null cost of changing units. You can do
>>>that by having a domain which behaved like that, but a shared runqueue
>>>sounds better because it would eliminate the cost of even considering
>>>moving a process from one sibling to another.
>>>
>>You are correct, however it would be a miniscule cost advantage,
>>possibly outweighed by the shared lock, and overhead of more
>>changing of CPUs (I'm sure there would be some cost).
>>
>
>Regarding the overhead of the shared runqueue lock:
>
>Is the "lock" prefix actually required for locking between x86
>siblings which share the same L1 cache?
>
That lock is still taken by other CPUs as well for eg. wakeups, balancing,
and so forth. I guess it could be a very specific optimisation for
spinlocks in general if there was only one HT core. Don't know if it
would be worthwhile though.
next prev parent reply other threads:[~2003-12-14 9:40 UTC|newest]
Thread overview: 80+ messages / expand[flat|nested] mbox.gz Atom feed top
2003-12-08 4:25 [PATCH][RFC] make cpu_sibling_map a cpumask_t Nick Piggin
2003-12-08 15:59 ` Anton Blanchard
2003-12-08 23:08 ` Nick Piggin
2003-12-09 0:14 ` Anton Blanchard
2003-12-11 4:25 ` [CFT][RFC] HT scheduler Nick Piggin
2003-12-11 7:24 ` Nick Piggin
2003-12-11 8:57 ` Nick Piggin
2003-12-11 11:52 ` William Lee Irwin III
2003-12-11 13:09 ` Nick Piggin
2003-12-11 13:23 ` William Lee Irwin III
2003-12-11 13:30 ` Nick Piggin
2003-12-11 13:32 ` William Lee Irwin III
2003-12-11 15:30 ` Nick Piggin
2003-12-11 15:38 ` William Lee Irwin III
2003-12-11 15:51 ` Nick Piggin
2003-12-11 15:56 ` William Lee Irwin III
2003-12-11 16:37 ` Nick Piggin
2003-12-11 16:40 ` William Lee Irwin III
2003-12-12 1:52 ` [PATCH] improve rwsem scalability (was Re: [CFT][RFC] HT scheduler) Nick Piggin
2003-12-12 2:02 ` Nick Piggin
2003-12-12 9:41 ` Ingo Molnar
2003-12-13 0:07 ` Nick Piggin
2003-12-14 0:44 ` Nick Piggin
2003-12-17 5:27 ` Nick Piggin
2003-12-19 11:52 ` Nick Piggin
2003-12-19 15:06 ` Martin J. Bligh
2003-12-20 0:08 ` Nick Piggin
2003-12-12 0:58 ` [CFT][RFC] HT scheduler Rusty Russell
2003-12-11 10:01 ` Rhino
2003-12-11 8:14 ` Nick Piggin
2003-12-11 16:49 ` Rhino
2003-12-11 15:16 ` Nick Piggin
2003-12-11 11:40 ` William Lee Irwin III
2003-12-11 17:05 ` Rhino
2003-12-11 15:17 ` William Lee Irwin III
2003-12-11 16:28 ` Kevin P. Fleming
2003-12-11 16:41 ` Nick Piggin
2003-12-12 2:24 ` Rusty Russell
2003-12-12 7:00 ` Nick Piggin
2003-12-12 7:23 ` Rusty Russell
2003-12-13 6:43 ` Nick Piggin
2003-12-14 1:35 ` bill davidsen
2003-12-14 2:18 ` Nick Piggin
2003-12-14 4:32 ` Jamie Lokier
2003-12-14 9:40 ` Nick Piggin [this message]
2003-12-14 10:46 ` Arjan van de Ven
2003-12-16 17:46 ` Bill Davidsen
2003-12-16 18:22 ` Linus Torvalds
2003-12-17 0:24 ` Davide Libenzi
2003-12-17 0:41 ` Linus Torvalds
2003-12-17 0:54 ` Davide Libenzi
2003-12-16 17:34 ` Bill Davidsen
2003-12-15 5:53 ` Rusty Russell
2003-12-15 23:08 ` Nick Piggin
2003-12-19 4:57 ` Nick Piggin
2003-12-19 5:13 ` Nick Piggin
2003-12-20 2:43 ` Rusty Russell
2003-12-21 2:56 ` Nick Piggin
2004-01-03 18:57 ` Bill Davidsen
2003-12-15 20:21 ` Zwane Mwaikambo
2003-12-15 23:20 ` Nick Piggin
2003-12-16 0:11 ` Zwane Mwaikambo
2003-12-12 8:59 ` Nick Piggin
2003-12-12 15:14 ` Martin J. Bligh
2003-12-08 19:44 ` [PATCH][RFC] make cpu_sibling_map a cpumask_t James Cleverdon
2003-12-08 20:38 ` Ingo Molnar
2003-12-08 20:51 ` Zwane Mwaikambo
2003-12-08 20:55 ` Ingo Molnar
2003-12-08 23:17 ` Nick Piggin
2003-12-08 23:36 ` Ingo Molnar
2003-12-08 23:58 ` Nick Piggin
2003-12-08 23:46 ` Rusty Russell
2003-12-09 13:36 ` Nick Piggin
2003-12-11 21:41 ` bill davidsen
[not found] <20031213022038.300B22C2C1@lists.samba.org.suse.lists.linux.kernel>
[not found] ` <3FDAB517.4000309@cyberone.com.au.suse.lists.linux.kernel>
[not found] ` <brgeo7$huv$1@gatekeeper.tmr.com.suse.lists.linux.kernel>
[not found] ` <3FDBC876.3020603@cyberone.com.au.suse.lists.linux.kernel>
[not found] ` <20031214043245.GC21241@mail.shareable.org.suse.lists.linux.kernel>
[not found] ` <3FDC3023.9030708@cyberone.com.au.suse.lists.linux.kernel>
[not found] ` <1071398761.5233.1.camel@laptop.fenrus.com.suse.lists.linux.kernel>
2003-12-14 16:26 ` [CFT][RFC] HT scheduler Andi Kleen
2003-12-14 16:54 ` Arjan van de Ven
[not found] <200312161127.13691.habanero@us.ibm.com>
2003-12-16 17:37 ` Andrew Theurer
2003-12-17 2:41 ` Nick Piggin
2003-12-16 19:03 Nakajima, Jun
2003-12-17 0:38 Nakajima, Jun
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