Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933340AbaGOTnr (ORCPT ); Tue, 15 Jul 2014 15:43:47 -0400 Received: from mx1.redhat.com ([209.132.183.28]:52106 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933133AbaGOTnp (ORCPT ); Tue, 15 Jul 2014 15:43:45 -0400 Date: Tue, 15 Jul 2014 15:43:19 -0400 (EDT) From: Mikulas Patocka X-X-Sender: mpatocka@file01.intranet.prod.int.rdu2.redhat.com To: "Alasdair G. Kergon" , Mike Snitzer , Jonathan Brassow , Edward Thornber , "Martin K. Petersen" , Jens Axboe , Christoph Hellwig cc: dm-devel@redhat.com, linux-kernel@vger.kernel.org, linux-scsi@vger.kernel.org Subject: [PATCH 13/15] dm kcopyd: support copy offload In-Reply-To: Message-ID: References: User-Agent: Alpine 2.02 (LRH 1266 2009-07-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This patch adds copy offload support to dm-kcopyd. If copy offload fails, copying is performed using dm-io, just like before. There is a module parameter "copy_offload" that can be set to enable or disable this feature. It can be used to test performance of copy offload. Signed-off-by: Mikulas Patocka --- drivers/md/dm-kcopyd.c | 38 +++++++++++++++++++++++++++++++++++++- 1 file changed, 37 insertions(+), 1 deletion(-) Index: linux-3.16-rc5/drivers/md/dm-kcopyd.c =================================================================== --- linux-3.16-rc5.orig/drivers/md/dm-kcopyd.c 2014-07-15 16:18:15.000000000 +0200 +++ linux-3.16-rc5/drivers/md/dm-kcopyd.c 2014-07-15 19:20:34.000000000 +0200 @@ -96,6 +96,9 @@ static DEFINE_SPINLOCK(throttle_spinlock */ #define MAX_SLEEPS 10 +static bool copy_offload = true; +module_param(copy_offload, bool, S_IRUGO | S_IWUSR); + static void io_job_start(struct dm_kcopyd_throttle *t) { unsigned throttle, now, difference; @@ -358,6 +361,8 @@ struct kcopyd_job { sector_t progress; struct kcopyd_job *master_job; + + struct work_struct copy_work; }; static struct kmem_cache *_job_cache; @@ -709,6 +714,31 @@ static void submit_job(struct kcopyd_job } } +static void copy_offload_work(struct work_struct *work) +{ + struct kcopyd_job *job = container_of(work, struct kcopyd_job, copy_work); + sector_t copied; + + blkdev_issue_copy(job->source.bdev, job->source.sector, + job->dests[0].bdev, job->dests[0].sector, + job->source.count, + GFP_NOIO | __GFP_NORETRY | __GFP_NOMEMALLOC | __GFP_NOWARN, + NULL, NULL, &copied); + + job->source.sector += copied; + job->source.count -= copied; + job->dests[0].sector += copied; + job->dests[0].count -= copied; + + submit_job(job); +} + +static void try_copy_offload(struct kcopyd_job *job) +{ + INIT_WORK(&job->copy_work, copy_offload_work); + queue_work(job->kc->kcopyd_wq, &job->copy_work); +} + int dm_kcopyd_copy(struct dm_kcopyd_client *kc, struct dm_io_region *from, unsigned int num_dests, struct dm_io_region *dests, unsigned int flags, dm_kcopyd_notify_fn fn, void *context) @@ -757,7 +787,13 @@ int dm_kcopyd_copy(struct dm_kcopyd_clie job->context = context; job->master_job = job; - submit_job(job); + if (copy_offload && num_dests == 1 && + bdev_copy_offload(job->source.bdev) && + bdev_copy_offload(job->dests[0].bdev)) { + try_copy_offload(job); + } else { + submit_job(job); + } return 0; } -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/