From patchwork Thu Aug 11 09:03:10 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kyungmin Park X-Patchwork-Id: 1056152 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by demeter1.kernel.org (8.14.4/8.14.4) with ESMTP id p7B93M7e012683 for ; Thu, 11 Aug 2011 09:03:23 GMT Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752041Ab1HKJDV (ORCPT ); Thu, 11 Aug 2011 05:03:21 -0400 Received: from mailout3.samsung.com ([203.254.224.33]:58500 "EHLO mailout3.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754531Ab1HKJDU (ORCPT ); Thu, 11 Aug 2011 05:03:20 -0400 Received: from epcpsbgm2.samsung.com (mailout3.samsung.com [203.254.224.33]) by mailout3.samsung.com (Oracle Communications Messaging Exchange Server 7u4-19.01 64bit (built Sep 7 2010)) with ESMTP id <0LPR006QAAHBEK10@mailout3.samsung.com>; Thu, 11 Aug 2011 18:03:19 +0900 (KST) X-AuditID: cbfee61b-b7c3dae000002cb8-a4-4e439ad7a3d6 Received: from epmmp2 ( [203.254.227.17]) by epcpsbgm2.samsung.com (MMPCPMTA) with SMTP id FC.25.11448.7DA934E4; Thu, 11 Aug 2011 18:03:19 +0900 (KST) Received: from TNRNDGASPAPP1.tn.corp.samsungelectronics.net ([165.213.149.150]) by mmp2.samsung.com (iPlanet Messaging Server 5.2 Patch 2 (built Jul 14 2004)) with ESMTPA id <0LPR006JQAHJ1E@mmp2.samsung.com>; Thu, 11 Aug 2011 18:03:19 +0900 (KST) Received: from july ([165.213.219.111]) by TNRNDGASPAPP1.tn.corp.samsungelectronics.net with Microsoft SMTPSVC(6.0.3790.4675); Thu, 11 Aug 2011 18:03:53 +0900 Received: by july (sSMTP sendmail emulation); Thu, 11 Aug 2011 18:03:10 +0900 Date: Thu, 11 Aug 2011 18:03:10 +0900 From: Kyungmin Park Subject: [RFC PATCH v3] Add new elevator ops for request context To: jaxboe@fusionio.com Cc: linux-kernel@vger.kernel.org, arnd@arndb.de, jh80.chung@samsung.com, shli@kernel.org, linux-mmc@vger.kernel.org Message-id: <20110811090310.GA6779@july> MIME-version: 1.0 Content-type: text/plain; charset=us-ascii Content-transfer-encoding: 7BIT Content-disposition: inline User-Agent: Mutt/1.5.17 (2007-11-01) X-OriginalArrivalTime: 11 Aug 2011 09:03:53.0155 (UTC) FILETIME=[97C98930:01CC5805] X-Brightmail-Tracker: AAAAAA== Sender: linux-mmc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-mmc@vger.kernel.org X-Greylist: IP, sender and recipient auto-whitelisted, not delayed by milter-greylist-4.2.6 (demeter1.kernel.org [140.211.167.41]); Thu, 11 Aug 2011 09:03:23 +0000 (UTC) Hi Jens Now eMMC device requires the upper layer information to improve the data performance and reliability. . Context ID Using the context information, it can sort out the data internally and improve the performance. The main problem is that it's needed to define "What's the context". Actually I expect cfq queue has own unique ID but it doesn't so decide to use the pid instead . Data Tag Using the Data Tag (1-bit information), It writes the data at SLC area when it's hot data. So it can make the chip more reliable. First I expect the REQ_META but current ext4 doesn't pass the WRITE_META. only use the READ_META. so it will modify the ext4 filesystem to send the REQ_META flags to know it from device drivers With these characteristics, it's helpful to teach the device. After some consideration. it's needed to use the elevator and request helpers Sample usage is following in drivers/mmc/card/block.c int context; if (req) context = elv_get_request_context(md->queue.queue, req); Thank you, Kyungmin Park --- Changelog v3 - Don't create the request_hint structure from Jens - Make a helper function from Jens/Shaohua Changelog v2 - Don't add the request member. instead add new elevator ops from Jens --- static void flush_end_io(struct request *flush_rq, int error) -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c index 1f96ad6..45187e3 100644 --- a/block/cfq-iosched.c +++ b/block/cfq-iosched.c @@ -3800,6 +3800,16 @@ queue_fail: return 1; } +static int cfq_get_request_context(struct request *rq) +{ + struct cfq_queue *cfqq = RQ_CFQQ(rq); + + if (cfqq) + return cfqq->pid; + + return 0; +} + static void cfq_kick_queue(struct work_struct *work) { struct cfq_data *cfqd = @@ -4211,6 +4221,7 @@ static struct elevator_type iosched_cfq = { .elevator_latter_req_fn = elv_rb_latter_request, .elevator_set_req_fn = cfq_set_request, .elevator_put_req_fn = cfq_put_request, + .elevator_get_req_context_fn = cfq_get_request_context, .elevator_may_queue_fn = cfq_may_queue, .elevator_init_fn = cfq_init_queue, .elevator_exit_fn = cfq_exit_queue, diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 0e67c45..e564500 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -551,6 +551,19 @@ static inline void blk_clear_queue_full(struct request_queue *q, int sync) queue_flag_clear(QUEUE_FLAG_ASYNCFULL, q); } +static inline int elv_get_request_context(struct request_queue *q, + struct request *rq) +{ + struct elevator_queue *e = q->elevator; + + if (!(rq->cmd_flags & REQ_ELVPRIV)) + return 0; + + if (e->ops->elevator_get_req_context_fn) + return e->ops->elevator_get_req_context_fn(rq); + + return 0; +} /* * mergeable request must not have _NOMERGE or _BARRIER bit set, nor may diff --git a/include/linux/elevator.h b/include/linux/elevator.h index d800d51..0005a6f 100644 --- a/include/linux/elevator.h +++ b/include/linux/elevator.h @@ -26,6 +26,7 @@ typedef int (elevator_may_queue_fn) (struct request_queue *, int); typedef int (elevator_set_req_fn) (struct request_queue *, struct request *, gfp_t); typedef void (elevator_put_req_fn) (struct request *); +typedef int (elevator_get_req_context_fn) (struct request *); typedef void (elevator_activate_req_fn) (struct request_queue *, struct request *); typedef void (elevator_deactivate_req_fn) (struct request_queue *, struct request *); @@ -52,6 +53,7 @@ struct elevator_ops elevator_set_req_fn *elevator_set_req_fn; elevator_put_req_fn *elevator_put_req_fn; + elevator_get_req_context_fn *elevator_get_req_context_fn; elevator_may_queue_fn *elevator_may_queue_fn;