Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932647Ab1EZSfr (ORCPT ); Thu, 26 May 2011 14:35:47 -0400 Received: from mx1.redhat.com ([209.132.183.28]:52024 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932308Ab1EZSfp (ORCPT ); Thu, 26 May 2011 14:35:45 -0400 Date: Thu, 26 May 2011 14:35:31 -0400 From: Mike Snitzer To: Mandeep Singh Baines Cc: linux-kernel@vger.kernel.org, jrbarnette@chromium.org, Neil Brown , Jens Axboe , "Martin K. Petersen" , Alasdair G Kergon , dm-devel@redhat.com Subject: [PATCH v2] dm: pass up non-rotational flag Message-ID: <20110526183531.GB26219@redhat.com> References: <1306356648-30730-1-git-send-email-msb@chromium.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1306356648-30730-1-git-send-email-msb@chromium.org> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2417 Lines: 74 Allow QUEUE_FLAG_NONROT to propagate up the device stack if all underlying devices are non-rotational. Tools like ureadahead will schedule IOs differently based on the rotational flag. With this patch, I see boot time go from 7.75 s to 7.46 s on my device. Suggested-by: J. Richard Barnette Signed-off-by: Mandeep Singh Baines Signed-off-by: Mike Snitzer Cc: Neil Brown Cc: Jens Axboe Cc: Martin K. Petersen Cc: Alasdair G Kergon Cc: dm-devel@redhat.com --- drivers/md/dm-table.c | 30 ++++++++++++++++++++++++++++++ 1 files changed, 30 insertions(+), 0 deletions(-) v2: last minute edit was to avoid double-negative in dm_table_set_restrictions's dm_table_is_nonrot conditional diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c index cb8380c..a173828 100644 --- a/drivers/md/dm-table.c +++ b/drivers/md/dm-table.c @@ -1177,6 +1177,31 @@ static void dm_table_set_integrity(struct dm_table *t) blk_get_integrity(template_disk)); } +static int device_is_nonrot(struct dm_target *ti, struct dm_dev *dev, + sector_t start, sector_t len, void *data) +{ + struct request_queue *q = bdev_get_queue(dev->bdev); + + return q && blk_queue_nonrot(q); +} + +static bool dm_table_is_nonrot(struct dm_table *t) +{ + struct dm_target *ti; + unsigned i = 0; + + /* Ensure that all underlying device are non-rotational. */ + while (i < dm_table_get_num_targets(t)) { + ti = dm_table_get_target(t, i++); + + if (!ti->type->iterate_devices || + !ti->type->iterate_devices(ti, device_is_nonrot, NULL)) + return 0; + } + + return 1; +} + void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q, struct queue_limits *limits) { @@ -1190,6 +1215,11 @@ void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q, else queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, q); + if (dm_table_is_nonrot(t)) + queue_flag_set_unlocked(QUEUE_FLAG_NONROT, q); + else + queue_flag_clear_unlocked(QUEUE_FLAG_NONROT, q); + dm_table_set_integrity(t); /* -- 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/