From mboxrd@z Thu Jan 1 00:00:00 1970 From: heechul@illinois.edu (heechul Yun) Date: Mon, 4 Jul 2011 07:59:59 -0700 Subject: Unnecessary cache-line flush on page table updates ? In-Reply-To: <20110704094531.GB19117@e102109-lin.cambridge.arm.com> References: <20110701101019.GA1723@e102109-lin.cambridge.arm.com> <20110704094531.GB19117@e102109-lin.cambridge.arm.com> Message-ID: To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Mon, Jul 4, 2011 at 2:45 AM, Catalin Marinas wrote: > On Fri, Jul 01, 2011 at 10:42:00PM +0100, heechul Yun wrote: >> Great. >> >> Removing the PTE flush seems to have a noticeable performance >> difference in my test. The followings are lmbench 3.0a performance >> result measured on a Cortex A9 SMP platform. So far, I did not have >> any problem while doing various test. >> >> ========= >> mm-patch: >> ========= >> Pagefaults on /tmp/XXX: 3.0759 microseconds >> Process fork+exit: 464.5414 microseconds >> Process fork+execve: 785.4944 microseconds >> Process fork+/bin/sh -c: 488.6204 microseconds >> >> ========= >> original: >> ========= >> Pagefaults on /tmp/XXX: 3.6209 microseconds >> Process fork+exit: 485.5236 microseconds >> Process fork+execve: 820.0613 microseconds >> Process fork+/bin/sh -c: 2966.3828 microseconds > > Given these results, I think it's worth merging the patch. Can I add > your Tested-by? Yes you can. I think this patch will be valuable for many applications (e.g., server applications). Heechul > > I think there can be a few other optimisations in the TLB area but it > needs some digging. > > Thanks. > > -- > Catalin >