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From: Ingo Molnar <mingo@elte.hu>
To: Bill Huey <bhuey@lnxw.com>
Cc: "David S. Miller" <davem@davemloft.net>,
	davidsen@tmr.com, linux-kernel@vger.kernel.org
Subject: Re: [patch] remove the BKL (Big Kernel Lock), this time for real
Date: Fri, 17 Sep 2004 08:43:21 +0200	[thread overview]
Message-ID: <20040917064321.GA8146@elte.hu> (raw)
In-Reply-To: <20040916225102.GA4386@nietzsche.lynx.com>


* Bill Huey <bhuey@lnxw.com> wrote:

> Judging from how the Linux code is done and the numbers I get from
> Bill Irwin in casual conversation, the Linux SMP approach is clearly
> the right track at this time with it's hand honed per-CPU awareness of
> things. The only serious problem that spinlocks have as they aren't
> preemptable, which is what Ingo is trying to fix.

a clarification: note that the current BKL is a special case. No way do
i suggest that the BKS is the proper model for any SMP implementation.
It is a narrow special-case because it wraps historic UP-only kernel
code.

our primary multiprocessing primitives are still the following 4:
lockless data structures, RCU, spinlocks and mutexes. (reverse ordered
by level of parallelism.) The BKS is basically a fifth method, a special
type of semaphore that i'd never want to be seen used by any new SMP
code. It is completely local to sched.c.

	Ingo

  parent reply	other threads:[~2004-09-17  6:42 UTC|newest]

Thread overview: 32+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <2EJTp-7bx-1@gated-at.bofh.it>
2004-09-15 15:46 ` [patch] remove the BKL (Big Kernel Lock), this time for real Andi Kleen
2004-09-15 15:58   ` Ingo Molnar
2004-09-15 20:11   ` Ingo Molnar
2004-09-16  1:17     ` Nick Piggin
2004-09-16 14:28   ` Bill Davidsen
2004-09-16 22:29     ` Bill Huey
2004-09-16 22:40       ` David S. Miller
2004-09-16 22:51         ` Bill Huey
2004-09-16 22:54           ` David S. Miller
2004-09-16 23:01             ` Bill Huey
2004-09-16 23:33             ` William Lee Irwin III
2004-09-17  6:43           ` Ingo Molnar [this message]
2004-09-17  7:21             ` Tony Lee
2004-09-18  5:44 Manfred Spraul
2004-09-18 13:09 ` Ingo Molnar
  -- strict thread matches above, loose matches on Subject: below --
2004-09-15 15:18 Ingo Molnar
2004-09-15 15:40 ` Linus Torvalds
2004-09-15 15:55   ` Ingo Molnar
2004-09-15 17:04     ` Ricky Beam
2004-09-15 19:39       ` Ingo Molnar
2004-09-15 18:28     ` Chris Wedgwood
2004-09-15 21:25   ` William Lee Irwin III
2004-09-17 10:39 ` Ingo Molnar
2004-09-17 12:53   ` Ingo Molnar
2004-09-17 20:56     ` Andrea Arcangeli
2004-09-18  8:02       ` Ingo Molnar
2004-09-18 23:36         ` Andrea Arcangeli
2004-09-17 13:26   ` Andrea Arcangeli
2004-09-17 13:47     ` William Lee Irwin III
2004-09-17 13:56       ` Andrea Arcangeli
2004-09-17 14:18         ` William Lee Irwin III
2004-09-17 15:16   ` Linus Torvalds

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