From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Thu, 1 Mar 2018 09:51:37 +0100 From: Johannes Thumshirn To: Bart Van Assche Cc: Jens Axboe , linux-block@vger.kernel.org, Christoph Hellwig , Hannes Reinecke , Ming Lei Subject: Re: [PATCH 04/11] block: Protect queue flag changes with the queue lock Message-ID: <20180301085137.6g3hgobf6kj2bosy@linux-x5ow.site> References: <20180228192823.5191-1-bart.vanassche@wdc.com> <20180228192823.5191-5-bart.vanassche@wdc.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 In-Reply-To: <20180228192823.5191-5-bart.vanassche@wdc.com> List-ID: On Wed, Feb 28, 2018 at 11:28:16AM -0800, Bart Van Assche wrote: > static bool blk_poll_stats_enable(struct request_queue *q) > { > - if (test_bit(QUEUE_FLAG_POLL_STATS, &q->queue_flags) || > - test_and_set_bit(QUEUE_FLAG_POLL_STATS, &q->queue_flags)) > + if (blk_queue_flag_test_and_set(QUEUE_FLAG_POLL_STATS, q)) Is this one really needed or just for symmetry? Even if something would change the queue_flags after the first test_bit() call, the test_and_set_bit() would still do the right thing, wouldn't it? -- Johannes Thumshirn Storage jthumshirn@suse.de +49 911 74053 689 SUSE LINUX GmbH, Maxfeldstr. 5, 90409 N�rnberg GF: Felix Imend�rffer, Jane Smithard, Graham Norton HRB 21284 (AG N�rnberg) Key fingerprint = EC38 9CAB C2C4 F25D 8600 D0D0 0393 969D 2D76 0850