Re: [PATCH] improve scalability of 2.4.21 fpassist

From: Bjorn Helgaas <>
Date: 2003-07-30 09:06:36
On Thursday 03 July 2003 2:36 pm, John Hawkes wrote:
> This change has already made its way into linux-2.5.72-ia64-031619.diff.
> Here is the diff relative to 2.4.21 + linux-2.4.21-ia64-030702.diff.
> This patch *significantly* improves the scalability of handle_fpu_swa()
> when multiple CPUs are generating concurrent fp-assist traps.
> The original algorithm produces cacheline ping-ponging for the cacheline
> that contains fpu_swa_count.  This new algorithm only dirties
> fpu_sw_count when the printk() is about to occur, rather than on every
> fpassist trap, which throttles the ping-ponging to no more than five per
> second.

I applied this for 2.4.  Thanks!


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Received on Tue Jul 29 19:07:03 2003

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