From patchwork Thu Nov 1 12:21:52 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: tlinder X-Patchwork-Id: 1684871 Return-Path: X-Original-To: patchwork-linux-mmc@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork2.kernel.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by patchwork2.kernel.org (Postfix) with ESMTP id 3D858DFE75 for ; Thu, 1 Nov 2012 12:22:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935367Ab2KAMWG (ORCPT ); Thu, 1 Nov 2012 08:22:06 -0400 Received: from wolverine02.qualcomm.com ([199.106.114.251]:5613 "EHLO wolverine02.qualcomm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933620Ab2KAMWF (ORCPT ); Thu, 1 Nov 2012 08:22:05 -0400 X-IronPort-AV: E=McAfee;i="5400,1158,6882"; a="3454346" Received: from pdmz-ns-snip_115.254.qualcomm.com (HELO mostmsg01.qualcomm.com) ([199.106.115.254]) by wolverine02.qualcomm.com with ESMTP/TLS/DHE-RSA-AES256-SHA; 01 Nov 2012 05:22:04 -0700 Received: from lx-tlinder2.qi.qualcomm.com (pdmz-ns-snip_218_1.qualcomm.com [192.168.218.1]) by mostmsg01.qualcomm.com (Postfix) with ESMTPA id 1334910004BF; Thu, 1 Nov 2012 05:22:01 -0700 (PDT) From: tlinder To: linux-mmc@vger.kernel.org Cc: linux-arm-msm@vger.kernel.org, philippedeswert@gmail.com, jengelh@inai.de, jh80.chung@samsung.com, tgih.jun@samsung.com, arnd.bergmann@linaro.org, Tatyana Brokhman , linux-kernel@vger.kernel.org (open list) Subject: [RFC/PATCH v2 1/2] block: Add support for reinsert a dispatched req Date: Thu, 1 Nov 2012 14:21:52 +0200 Message-Id: <1351772516-10423-1-git-send-email-tlinder@codeaurora.org> X-Mailer: git-send-email 1.7.6 Sender: linux-mmc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-mmc@vger.kernel.org From: Tatyana Brokhman Add support for reinserting a dispatched request back to the schedulers internal data structures. Add API for verifying whether the current scheduler supports reinserting requests mechanism Signed-off-by: Tatyana Brokhman diff --git a/block/blk-core.c b/block/blk-core.c index b421289..8881e46 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -1177,6 +1177,45 @@ void blk_requeue_request(struct request_queue *q, struct request *rq) } EXPORT_SYMBOL(blk_requeue_request); +/** + * blk_reinsert_request() - Insert a request back to the scheduler + * @q: request queue + * @rq: request to be inserted + * + * This function inserts the request back to the scheduler as if + * it was never dispatched. + * + * Return: 0 on success, error code on fail + */ +int blk_reinsert_request(struct request_queue *q, struct request *rq) +{ + blk_delete_timer(rq); + blk_clear_rq_complete(rq); + trace_block_rq_requeue(q, rq); + + if (blk_rq_tagged(rq)) + blk_queue_end_tag(q, rq); + + BUG_ON(blk_queued_rq(rq)); + + return elv_reinsert_request(q, rq); +} +EXPORT_SYMBOL(blk_reinsert_request); + +/** + * blk_reinsert_req_sup() - check whether the scheduler supports + * reinsertion of requests + * @q: request queue + * + * Returns true if the current scheduler supports reinserting + * request. False otherwise + */ +bool blk_reinsert_req_sup(struct request_queue *q) +{ + return q->elevator->type->ops.elevator_reinsert_req_fn ? true : false; +} +EXPORT_SYMBOL(blk_reinsert_req_sup); + static void add_acct_request(struct request_queue *q, struct request *rq, int where) { diff --git a/block/elevator.c b/block/elevator.c index 9b1d42b..121a351 100644 --- a/block/elevator.c +++ b/block/elevator.c @@ -539,6 +539,36 @@ void elv_requeue_request(struct request_queue *q, struct request *rq) __elv_add_request(q, rq, ELEVATOR_INSERT_REQUEUE); } +/** + * elv_reinsert_request() - Insert a request back to the scheduler + * @q: request queue where request should be inserted + * @rq: request to be inserted + * + * This function returns the request back to the scheduler to be + * inserted as if it was never dispatched + * + * Return: 0 on success, error code on failure + */ +int elv_reinsert_request(struct request_queue *q, struct request *rq) +{ + if (!q->elevator->type->ops.elevator_reinsert_req_fn) + return -EPERM; + /* + * it already went through dequeue, we need to decrement the + * in_flight count again + */ + if (blk_account_rq(rq)) { + q->in_flight[rq_is_sync(rq)]--; + if (rq->cmd_flags & REQ_SORTED) + elv_deactivate_rq(q, rq); + } + + rq->cmd_flags &= ~REQ_STARTED; + q->nr_sorted++; + + return q->elevator->type->ops.elevator_reinsert_req_fn(q, rq); +} + void elv_drain_elevator(struct request_queue *q) { static int printed; diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 1756001..e725303 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -722,6 +722,8 @@ extern struct request *blk_get_request(struct request_queue *, int, gfp_t); extern struct request *blk_make_request(struct request_queue *, struct bio *, gfp_t); extern void blk_requeue_request(struct request_queue *, struct request *); +extern int blk_reinsert_request(struct request_queue *q, struct request *rq); +extern bool blk_reinsert_req_sup(struct request_queue *q); extern void blk_add_request_payload(struct request *rq, struct page *page, unsigned int len); extern int blk_rq_check_limits(struct request_queue *q, struct request *rq); diff --git a/include/linux/elevator.h b/include/linux/elevator.h index c03af76..f70d05d 100644 --- a/include/linux/elevator.h +++ b/include/linux/elevator.h @@ -22,6 +22,8 @@ typedef void (elevator_bio_merged_fn) (struct request_queue *, typedef int (elevator_dispatch_fn) (struct request_queue *, int); typedef void (elevator_add_req_fn) (struct request_queue *, struct request *); +typedef int (elevator_reinsert_req_fn) (struct request_queue *, + struct request *); typedef struct request *(elevator_request_list_fn) (struct request_queue *, struct request *); typedef void (elevator_completed_req_fn) (struct request_queue *, struct request *); typedef int (elevator_may_queue_fn) (struct request_queue *, int); @@ -47,6 +49,8 @@ struct elevator_ops elevator_dispatch_fn *elevator_dispatch_fn; elevator_add_req_fn *elevator_add_req_fn; + elevator_reinsert_req_fn *elevator_reinsert_req_fn; + elevator_activate_req_fn *elevator_activate_req_fn; elevator_deactivate_req_fn *elevator_deactivate_req_fn; @@ -123,6 +127,7 @@ extern void elv_merged_request(struct request_queue *, struct request *, int); extern void elv_bio_merged(struct request_queue *q, struct request *, struct bio *); extern void elv_requeue_request(struct request_queue *, struct request *); +extern int elv_reinsert_request(struct request_queue *, struct request *); extern struct request *elv_former_request(struct request_queue *, struct request *); extern struct request *elv_latter_request(struct request_queue *, struct request *); extern int elv_register_queue(struct request_queue *q);