From mboxrd@z Thu Jan 1 00:00:00 1970 From: Minchan Kim Subject: Re: [PATCHv2 00/16] [FS, MM, block, MMC]: eMMC High Priority Interrupt Feature Date: Mon, 14 May 2012 16:55:39 +0900 Message-ID: <4FB0BA7B.1050200@kernel.org> References: <1336054995-22988-1-git-send-email-svenkatr@ti.com> <4FA8CF5E.1070202@kernel.org> <4FA9BE10.1030007@kernel.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: linux-mmc@vger.kernel.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, linux-omap@vger.kernel.org, linux-kernel@vger.kernel.org To: mani Return-path: In-Reply-To: Sender: linux-omap-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org On 05/14/2012 04:43 PM, mani wrote: > Dear Kim, > > I have a query here .. > > > My point is that it would be better for read to not preempt > write-for-page_reclaim. > And we can identify it by PG_reclaim. You can get the idea. > > I think If there is no page available then no read will proceed. > When read request comes it reclaim the pages (starts the write if > syncable pages ) and get back after reclaiming the pages. > Only then a read request will come to the MMC subsystem. > And i think the reclaim algorithm will reclaim some substantial amount > of pages at a time instead of a single page. > So if we get few pages during the reclamation so there will be no > problem in halting the another write ops for proceeding the reads ? > > Can we think of a scenario when we are reclaiming the pages and write > ops is going on where as a high priority read for the interrupt handler > is pending ? > > Please correct me if i am wrong. For example, System can have lots of order-0 pages but little order-big pages. In this case, for getting big contiguos memory, reclaimer should write out dirty pages while it can handle order-0 page read request. > > Thanks & Regards > Manish -- Kind regards, Minchan Kim