Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758655Ab1BLG2z (ORCPT ); Sat, 12 Feb 2011 01:28:55 -0500 Received: from mga09.intel.com ([134.134.136.24]:38613 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758199Ab1BLG2r (ORCPT ); Sat, 12 Feb 2011 01:28:47 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.60,460,1291622400"; d="scan'208";a="601972110" Date: Sat, 12 Feb 2011 14:22:14 +0800 From: Chuanxiao Dong To: linux-mmc@vger.kernel.org, cjb@laptop.org Cc: linux-kernel@vger.kernel.org, akpm@linux-foundation.org, adrian.hunter@nokia.com Subject: [PATCH v4 1/3]mmc: set max_discard_sectors value for mmc queue Message-ID: <20110212062214.GB25519@intel.com> Reply-To: Chuanxiao Dong MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.19 (2009-01-05) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3151 Lines: 79 max_discard_sectors value is UINT_MAX which means kernel block layer can pass down unlimited sectors to MMC driver to erase. But erasing so many sectors may delay some other important I/O requests. This is not preferred. So use 'pref_erase' to set a suitable max_discard_sectors value for mmc queue to avoid erasing too many sectors at one time. Signed-off-by: Chuanxiao Dong --- drivers/mmc/card/queue.c | 3 ++- drivers/mmc/core/core.c | 20 ++++++++++++++++++++ include/linux/mmc/core.h | 1 + 3 files changed, 23 insertions(+), 1 deletions(-) diff --git a/drivers/mmc/card/queue.c b/drivers/mmc/card/queue.c index 4e42d03..6c13859 100644 --- a/drivers/mmc/card/queue.c +++ b/drivers/mmc/card/queue.c @@ -131,7 +131,8 @@ int mmc_init_queue(struct mmc_queue *mq, struct mmc_card *card, spinlock_t *lock queue_flag_set_unlocked(QUEUE_FLAG_NONROT, mq->queue); if (mmc_can_erase(card)) { queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, mq->queue); - mq->queue->limits.max_discard_sectors = UINT_MAX; + mq->queue->limits.max_discard_sectors = + mmc_set_max_discard_sectors(card); if (card->erased_byte == 0) mq->queue->limits.discard_zeroes_data = 1; if (!mmc_can_trim(card) && is_power_of_2(card->erase_size)) { diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c index 34a7e8c..0eb27aa 100644 --- a/drivers/mmc/core/core.c +++ b/drivers/mmc/core/core.c @@ -1470,6 +1470,26 @@ int mmc_erase_group_aligned(struct mmc_card *card, unsigned int from, } EXPORT_SYMBOL(mmc_erase_group_aligned); +/* + * Set max_discard_sectors for mmc queue. + * max_discard_sectors will determine how many sectors can be erased at one + * time. Sometimes user may want to erase a large area of SD or MMC card, it may + * take long time which delay some other important I/O requests. So we would + * better set some values for max_discard_sectors which can forbid block layer + * pass too many sectors at one time. + * + * 'pref_erase' is initialized for this purpose. We can use it to set a preferred + * value for it. + */ +int mmc_set_max_discard_sectors(struct mmc_card *card) +{ + if (card->pref_erase) + return card->pref_erase; + else + return UINT_MAX; +} +EXPORT_SYMBOL(mmc_set_max_discard_sectors); + int mmc_set_blocklen(struct mmc_card *card, unsigned int blocklen) { struct mmc_command cmd; diff --git a/include/linux/mmc/core.h b/include/linux/mmc/core.h index 64e013f..a218d57 100644 --- a/include/linux/mmc/core.h +++ b/include/linux/mmc/core.h @@ -152,6 +152,7 @@ extern int mmc_can_trim(struct mmc_card *card); extern int mmc_can_secure_erase_trim(struct mmc_card *card); extern int mmc_erase_group_aligned(struct mmc_card *card, unsigned int from, unsigned int nr); +extern int mmc_set_max_discard_sectors(struct mmc_card *card); extern int mmc_set_blocklen(struct mmc_card *card, unsigned int blocklen); -- 1.6.6.1 -- 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/