From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bjorn Helgaas Date: Tue, 29 Jul 2003 23:06:36 +0000 Subject: Re: [PATCH] improve scalability of 2.4.21 fpassist Message-Id: List-Id: References: In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-ia64@vger.kernel.org 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! Bjorn