From: Russell King <rmk+lkml@arm.linux.org.uk>
To: Ingo Molnar <mingo@elte.hu>
Cc: "Chen, Kenneth W" <kenneth.w.chen@intel.com>,
Keith Owens <kaos@ocs.com.au>,
David.Mosberger@acm.org, Andrew Morton <akpm@osdl.org>,
linux-kernel@vger.kernel.org, linux-ia64@vger.kernel.org
Subject: Re: Add prefetch switch stack hook in scheduler function
Date: Fri, 29 Jul 2005 10:02:57 +0100 [thread overview]
Message-ID: <20050729100257.A10345@flint.arm.linux.org.uk> (raw)
In-Reply-To: <20050729082826.GA6144@elte.hu>; from mingo@elte.hu on Fri, Jul 29, 2005 at 10:28:26AM +0200
On Fri, Jul 29, 2005 at 10:28:26AM +0200, Ingo Molnar wrote:
> @@ -2872,10 +2878,10 @@ go_idle:
> /*
> * Prefetch (at least) a cacheline below the current
> * kernel stack (in expectation of any new task touching
> - * the stack at least minimally), and a cacheline above
> - * the stack:
> + * the stack at least minimally), and at least a cacheline
> + * above the stack:
> */
> - prefetch_range(kernel_stack(next) - MIN_KERNEL_STACK_FOOTPRINT,
> + prefetch_range(kernel_stack(next) - L1_CACHE_BYTES,
> MIN_KERNEL_STACK_FOOTPRINT + L1_CACHE_BYTES);
This needs to ensure that we don't prefetch outside the page of the
kernel stack - otherwise we risk weird problems on architectures
which support prefetching but not DMA cache coherency.
--
Russell King
Linux kernel 2.6 ARM Linux - http://www.arm.linux.org.uk/
maintainer of: 2.6 Serial core
next prev parent reply other threads:[~2005-07-29 9:03 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-07-27 22:07 Add prefetch switch stack hook in scheduler function Chen, Kenneth W
2005-07-27 23:13 ` Andrew Morton
2005-07-27 23:23 ` david mosberger
2005-07-28 7:41 ` Ingo Molnar
2005-07-28 8:09 ` Keith Owens
2005-07-28 8:16 ` Ingo Molnar
2005-07-28 9:09 ` Ingo Molnar
2005-07-28 19:14 ` Chen, Kenneth W
2005-07-29 7:04 ` Ingo Molnar
2005-07-29 7:07 ` Ingo Molnar
2005-07-29 8:30 ` Eric Dumazet
2005-07-29 8:44 ` Ingo Molnar
2005-07-31 16:27 ` hashed spinlocks Daniel Walker
2005-07-31 18:46 ` David S. Miller
2005-07-31 19:06 ` Daniel Walker
2005-07-31 19:11 ` David S. Miller
2005-07-31 19:16 ` Daniel Walker
2005-07-29 8:30 ` Add prefetch switch stack hook in scheduler function Chen, Kenneth W
2005-07-29 8:35 ` Ingo Molnar
2005-07-29 8:39 ` Chen, Kenneth W
2005-07-29 9:17 ` Peter Zijlstra
2005-07-29 10:52 ` Ingo Molnar
2005-07-29 7:22 ` Chen, Kenneth W
2005-07-29 7:45 ` Keith Owens
2005-07-29 8:02 ` Chen, Kenneth W
2005-07-29 8:28 ` Ingo Molnar
2005-07-29 9:02 ` Russell King [this message]
2005-07-29 9:45 ` Ingo Molnar
2005-07-29 7:38 ` Keith Owens
2005-07-29 8:08 ` Chen, Kenneth W
2005-07-28 8:31 ` Nick Piggin
2005-07-28 8:35 ` Ingo Molnar
2005-07-28 8:48 ` Nick Piggin
2005-07-28 9:16 ` Ingo Molnar
2005-07-28 9:19 ` Ingo Molnar
2005-07-28 9:34 ` Nick Piggin
2005-07-28 10:04 ` Ingo Molnar
2005-07-28 10:29 ` Nick Piggin
-- strict thread matches above, loose matches on Subject: below --
2005-07-29 15:18 linux
2005-07-29 15:49 ` Ingo Molnar
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