From mboxrd@z Thu Jan 1 00:00:00 1970 From: bill4carson@gmail.com (bill4carson) Date: Fri, 03 Feb 2012 18:09:08 +0800 Subject: [PATCH] Skip unnecessary pte makeup when clearing it. In-Reply-To: <20120203093518.GH25594@pengutronix.de> References: <1327912567-18966-1-git-send-email-bill4carson@gmail.com> <1327912567-18966-2-git-send-email-bill4carson@gmail.com> <20120203065432.GG25594@pengutronix.de> <4F2B903E.5070609@gmail.com> <20120203093518.GH25594@pengutronix.de> Message-ID: <4F2BB244.8060607@gmail.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 2012?02?03? 17:35, Uwe Kleine-K?nig wrote: > On Fri, Feb 03, 2012 at 03:43:58PM +0800, bill4carson wrote: >> >> >> On 2012?02?03? 14:54, Uwe Kleine-K?nig wrote: >>> Hello, >>> >>> On Mon, Jan 30, 2012 at 04:36:07PM +0800, bill4carson at gmail.com wrote: >>>> From: Bill Carson >>>> >>>> If we are only about to clear a hardware pte entry, then pte makeup code is >>>> unnecessary for cpu_v7_set_pte_ext and armv6_set_pte_ext, so just skip it. >>>> >>>> Signed-off-by: Bill Carson >>> I havn't tested and I don't know if the patch brings any advantages like >>> increased speed. But AFAICT it doesn't change the behaviour of >>> armv6_set_pte_ext and cpu_v7_set_pte_ext. >>> >> Hi, Uwe >> >> I'm sorry I didn't state the purpose of this patch clearly. >> As a matter of fact, it does change the behavior of set_pte_ext :) > Depends on what you call behaviour (and it's not the 'u' you dropped > that makes a difference :-). I meant that the side effects don't change. > It's only that they are accomplished in a different (probably more > effective) way. > Thanks for your explanation, I'm getting what you mean now :) Yes, from outside point of view, set_pte_ext provides exact function as before, from inside point of view, it will behave faster than before with this little modification. I see no reason why not do so. Or am I missing something here? > Best regards > Uwe > -- I am a slow learner but I will keep trying to fight for my dreams! --bill