From mboxrd@z Thu Jan 1 00:00:00 1970 From: Konstantin Dorfman Subject: Re: [PATCH] mmc: queue: exclude asynchronous transfer for special request Date: Sat, 22 Dec 2012 12:56:24 +0200 Message-ID: <50D591D8.9080503@codeaurora.org> References: <003c01cdde9c$95883ad0$c098b070$%jun@samsung.com> <50D3263F.6050407@codeaurora.org> <001801cddf3d$23b78040$6b2680c0$%jun@samsung.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from wolverine02.qualcomm.com ([199.106.114.251]:60228 "EHLO wolverine02.qualcomm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751024Ab2LVK42 (ORCPT ); Sat, 22 Dec 2012 05:56:28 -0500 In-Reply-To: <001801cddf3d$23b78040$6b2680c0$%jun@samsung.com> Sender: linux-mmc-owner@vger.kernel.org List-Id: linux-mmc@vger.kernel.org To: Seungwon Jeon Cc: linux-mmc@vger.kernel.org, 'Chris Ball' , 'Per Forlin' On 12/21/2012 07:36 AM, Seungwon Jeon wrote: > On Thursday, December 20, 2012, Konstantin Dorfman wrote: >> Hello Jeon, >> >> >> On 12/20/2012 12:27 PM, Seungwon Jeon wrote: >>> Unlike normal r/w request, special requests(discard, flush) >>> is finished with a one-time issue_fn. Request change to >>> mqrq_prev makes unnecessary call. >>> >>> Signed-off-by: Seungwon Jeon >>> --- >>> drivers/mmc/card/queue.c | 8 ++++++++ >>> 1 files changed, 8 insertions(+), 0 deletions(-) >>> >>> diff --git a/drivers/mmc/card/queue.c b/drivers/mmc/card/queue.c >>> index fadf52e..a71db7a 100644 >>> --- a/drivers/mmc/card/queue.c >>> +++ b/drivers/mmc/card/queue.c >>> @@ -58,6 +58,7 @@ static int mmc_queue_thread(void *d) >>> do { >>> struct request *req = NULL; >>> struct mmc_queue_req *tmp; >>> + unsigned int cmd_flags = 0; >>> >>> spin_lock_irq(q->queue_lock); >>> set_current_state(TASK_INTERRUPTIBLE); >>> @@ -67,12 +68,19 @@ static int mmc_queue_thread(void *d) >>> >>> if (req || mq->mqrq_prev->req) { >>> set_current_state(TASK_RUNNING); >>> + cmd_flags = req ? req->cmd_flags : 0; >>> mq->issue_fn(mq, req); >>> >>> /* >>> * Current request becomes previous request >>> * and vice versa. >>> + * In case of special requests, current request >>> + * has been finished. Do not remain it to previous >>> + * request. >>> */ >>> + if (cmd_flags & REQ_DISCARD || cmd_flags & REQ_FLUSH) >>> + mq->mqrq_cur->req = NULL; >>> + >>> mq->mqrq_prev->brq.mrq.data = NULL; >>> mq->mqrq_prev->req = NULL; >>> tmp = mq->mqrq_prev; >>> >> It is better to define control mask, REQ_CONTROL_MASK, which will >> include all control/special requests. > Agree, it's better. > >> >> Then, when additional request will be added, there will be no need to >> change here, only update the mask. >> >> Another option - to clean mq->mqrq_cur->req immediately after executing >> a special request in mmc_blk_issue_rq(). > Yes, I also approached it with the same idea at the beginning. > But it seems that 'queue.c' has a role of management of two requests, > while 'block.c' just uses these request. It makes sense? Sure, agree with you. Thanks, -- Konstantin Dorfman, QUALCOMM ISRAEL, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation