From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dave Jones Date: Sun, 26 Oct 2003 14:51:56 +0000 Subject: Re: [PATCH 2.4.23-pre8] Remove broken prefetching in free_one_pgd() 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 Sat, Oct 25, 2003 at 10:10:10PM +0200, Pavel Machek wrote: > > This patch was accepted into 2.5.55, attributed to "davej@uk". > Dave Jones?n Yep. > > This code will prefetch from beyond the end of the page table > > being cleared ... which is clearly a bad thing if the page table > > in question is allocated from the last page of memory (or precedes > > a hole on a discontig mem system). > Prefetching random addresses should be safe... It isn't on some CPUs. Early athlons go bang when you prefetch past the end of RAM into unmapped memory for eg. Dave -- Dave Jones http://www.codemonkey.org.uk