From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: ARC-Seal: i=1; a=rsa-sha256; t=1526656451; cv=none; d=google.com; s=arc-20160816; b=Auq5ejfEqZ0cyNMotuyBorMozNjKbZMxqqj5UsEzuBvAJ406Dl4Xi62kVmnnw4ptOO WtEZuYzVBCu7r0Ciegv7MJ2PlD6MFfW1eYhMVNCs3syIjCtlo3kxYJj5hbNeEGo3PaLK 7Pg2bczmalQhLUDGlcdQ1WfJtap/Qiyr6UpujKJHSBHF/W8zMWh3hyXjQRZkfFvaIOmT HfQ+Z0Rfe3GWC+UFnrsOINAoTbHgG+COfaEqaoblIPb4F0KjxR7eoa490iBfLGzaXutP antyYi4Q4Q4BvaUeNFMa12BCrR3vrHnNU3ksvHLh9XFwRvJ/zHcPK8rDvNTbPgCyRlt+ uaSA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=content-transfer-encoding:content-language:in-reply-to:mime-version :user-agent:date:message-id:from:references:cc:to:subject :dkim-signature:arc-authentication-results; bh=Sdxr38V5YQc092pPjeavYodUwFp9EY3rmLVMEJcULkg=; b=A82dtBjs95qn7qsDyF8A/CwgzsSzhw+Ikkhb0NXVXisd23h8PuQk9fiJnDWgRkWHrQ hiwnuXZBLOrbA/h9wjkyn5d4TYB4Z1LcsEJjlyY5utXq1iEMPyJPnJCWeLDGgcgDDSSn LJLt4fAK1iEjU95e28Y/Jl2/FljGOuu+WJZatYZOyHv7qmzrJ6T9dc4jKvDq3h906kNL scZCQUgFJikuTaALE5AIHW/E7tK/G2ct4SW8TSRrorD8mkY9XxS8P0uXPC6g2bVz4avC kNn+5AXA8oyeLIHHxr6Y6ngrMM8IJUjLfA12xAvBjpLGTRMH1dm0eQjrtKwNiN3lGh6v asMA== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@kernel-dk.20150623.gappssmtp.com header.s=20150623 header.b=0bcwunU9; spf=pass (google.com: domain of axboe@kernel.dk designates 209.85.220.65 as permitted sender) smtp.mailfrom=axboe@kernel.dk Authentication-Results: mx.google.com; dkim=pass header.i=@kernel-dk.20150623.gappssmtp.com header.s=20150623 header.b=0bcwunU9; spf=pass (google.com: domain of axboe@kernel.dk designates 209.85.220.65 as permitted sender) smtp.mailfrom=axboe@kernel.dk X-Google-Smtp-Source: AB8JxZp4o70k8r3AhYVy+u4BmqgVx1qAVl2b/ZVtpTqoPKME0LnGD5fexnkKLidamWhkn0ZaQRT1fA== Subject: Re: [PATCH v4 3/3] fs: Add aio iopriority support for block_dev To: adam.manzanares@wdc.com, viro@zeniv.linux.org.uk, linux-fsdevel@vger.kernel.org, bcrl@kvack.org Cc: mingo@kernel.org, peterz@infradead.org, pombredanne@nexb.com, gregkh@linuxfoundation.org, bigeasy@linutronix.de, rgoldwyn@suse.com, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, linux-aio@kvack.org, linux-api@vger.kernel.org References: <20180517203803.2664-1-adam.manzanares@wdc.com> <20180517203803.2664-4-adam.manzanares@wdc.com> From: Jens Axboe Message-ID: <51cbf2e9-1ff9-b9e7-fb68-055a64d54da5@kernel.dk> Date: Fri, 18 May 2018 09:14:07 -0600 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.0 MIME-Version: 1.0 In-Reply-To: <20180517203803.2664-4-adam.manzanares@wdc.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: =?utf-8?q?1600745118592233857?= X-GMAIL-MSGID: =?utf-8?q?1600815315694946092?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: On 5/17/18 2:38 PM, adam.manzanares@wdc.com wrote: > From: Adam Manzanares > > This is the per-I/O equivalent of the ioprio_set system call. > > When IOCB_FLAG_IOPRIO is set on the iocb aio_flags field, then we set the > newly added kiocb ki_ioprio field to the value in the iocb aio_reqprio field. > > When a bio is created for an aio request by the block dev we set the priority > value of the bio to the user supplied value. > > This patch depends on block: add ioprio_check_cap function Actually, one comment on this one: > diff --git a/fs/aio.c b/fs/aio.c > index f3eae5d5771b..ff3107aa82d5 100644 > --- a/fs/aio.c > +++ b/fs/aio.c > @@ -1451,6 +1451,22 @@ static int aio_prep_rw(struct kiocb *req, struct iocb *iocb) > if (iocb->aio_flags & IOCB_FLAG_RESFD) > req->ki_flags |= IOCB_EVENTFD; > req->ki_hint = file_write_hint(req->ki_filp); > + if (iocb->aio_flags & IOCB_FLAG_IOPRIO) { > + /* > + * If the IOCB_FLAG_IOPRIO flag of aio_flags is set, then > + * aio_reqprio is interpreted as an I/O scheduling > + * class and priority. > + */ > + ret = ioprio_check_cap(iocb->aio_reqprio); > + if (ret) { > + pr_debug("aio ioprio check cap error\n"); > + return -EINVAL; > + } > + > + req->ki_ioprio = iocb->aio_reqprio; > + req->ki_flags |= IOCB_IOPRIO; > + } Do we really need IOCB_IOPRIO? All zeroes is no priority set anyway, so we should be able to get by with just setting ->ki_ioprio to either the priority, or 0. > diff --git a/fs/block_dev.c b/fs/block_dev.c > index 7ec920e27065..970bef79caa6 100644 > --- a/fs/block_dev.c > +++ b/fs/block_dev.c > @@ -355,6 +355,8 @@ __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter, int nr_pages) > bio->bi_write_hint = iocb->ki_hint; > bio->bi_private = dio; > bio->bi_end_io = blkdev_bio_end_io; > + if (iocb->ki_flags & IOCB_IOPRIO) > + bio->bi_ioprio = iocb->ki_ioprio; And then this assignment can just happen unconditionally. -- Jens Axboe