From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from dggsgout11.his.huawei.com (unknown [45.249.212.51]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D9D58134C1; Tue, 16 Jan 2024 10:24:53 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=huaweicloud.com Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=huaweicloud.com Received: from mail.maildlp.com (unknown [172.19.93.142]) by dggsgout11.his.huawei.com (SkyGuard) with ESMTP id 4TDlVy14ZSz4f3lfx; Tue, 16 Jan 2024 18:24:42 +0800 (CST) Received: from mail02.huawei.com (unknown [10.116.40.112]) by mail.maildlp.com (Postfix) with ESMTP id 3B14F1A016E; Tue, 16 Jan 2024 18:24:48 +0800 (CST) Received: from [10.174.176.73] (unknown [10.174.176.73]) by APP1 (Coremail) with SMTP id cCh0CgAX6RFsWaZlZq0DBA--.11427S3; Tue, 16 Jan 2024 18:24:46 +0800 (CST) Subject: Re: [PATCH v6 1/4] block: Make fair tag sharing configurable To: Bart Van Assche , Yu Kuai , Christoph Hellwig Cc: Jens Axboe , linux-block@vger.kernel.org, linux-scsi@vger.kernel.org, "Martin K . Petersen" , Ming Lei , Keith Busch , Damien Le Moal , Ed Tsai , Matthias Brugger , AngeloGioacchino Del Regno , "yukuai (C)" References: <20231130193139.880955-1-bvanassche@acm.org> <20231130193139.880955-2-bvanassche@acm.org> <58f50403-fcc9-ec11-f52b-f11ced3d2652@huaweicloud.com> <8372f2d0-b695-4af4-90e6-e35b86e3b844@acm.org> <1d3866af-ffca-4f97-914d-8084aca901ab@acm.org> <69b17db7-e9c9-df09-1022-ff7a9e5e04dd@huaweicloud.com> <20240112043915.GA5664@lst.de> <2d83fcb3-06e6-4a7c-9bd7-b8018208b72f@huaweicloud.com> <20240115055940.GA745@lst.de> <0d23e3d3-1d7a-f76b-307b-7d74b3f91e05@huaweicloud.com> From: Yu Kuai Message-ID: Date: Tue, 16 Jan 2024 18:24:44 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 Precedence: bulk X-Mailing-List: linux-scsi@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit X-CM-TRANSID:cCh0CgAX6RFsWaZlZq0DBA--.11427S3 X-Coremail-Antispam: 1UD129KBjvJXoWrZw1fuw17Kry8Zr17GrWkCrg_yoW8Jrykpa yFqasakF4Dtr17Awn7Gry7XFy8Zws3tryUCFn5J34Yyrn8WF4xXryxtayY9FWDXwsrWr42 9r4vvr98A3s5Z3DanT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUU9214x267AKxVW8JVW5JwAFc2x0x2IEx4CE42xK8VAvwI8IcIk0 rVWrJVCq3wAFIxvE14AKwVWUJVWUGwA2ocxC64kIII0Yj41l84x0c7CEw4AK67xGY2AK02 1l84ACjcxK6xIIjxv20xvE14v26F1j6w1UM28EF7xvwVC0I7IYx2IY6xkF7I0E14v26r4U JVWxJr1l84ACjcxK6I8E87Iv67AKxVW0oVCq3wA2z4x0Y4vEx4A2jsIEc7CjxVAFwI0_Gc CE3s1le2I262IYc4CY6c8Ij28IcVAaY2xG8wAqx4xG64xvF2IEw4CE5I8CrVC2j2WlYx0E 2Ix0cI8IcVAFwI0_Jr0_Jr4lYx0Ex4A2jsIE14v26r1j6r4UMcvjeVCFs4IE7xkEbVWUJV W8JwACjcxG0xvEwIxGrwACjI8F5VA0II8E6IAqYI8I648v4I1lFIxGxcIEc7CjxVA2Y2ka 0xkIwI1lc7I2V7IY0VAS07AlzVAYIcxG8wCF04k20xvY0x0EwIxGrwCFx2IqxVCFs4IE7x kEbVWUJVW8JwC20s026c02F40E14v26r1j6r18MI8I3I0E7480Y4vE14v26r106r1rMI8E 67AF67kF1VAFwI0_Jw0_GFylIxkGc2Ij64vIr41lIxAIcVC0I7IYx2IY67AKxVWUJVWUCw CI42IY6xIIjxv20xvEc7CjxVAFwI0_Gr0_Cr1lIxAIcVCF04k26cxKx2IYs7xG6rWUJVWr Zr1UMIIF0xvEx4A2jsIE14v26r1j6r4UMIIF0xvEx4A2jsIEc7CjxVAFwI0_Gr0_Gr1UYx BIdaVFxhVjvjDU0xZFpf9x0JUdHUDUUUUU= X-CM-SenderInfo: 51xn3trlr6x35dzhxuhorxvhhfrp/ Hi, 在 2024/01/16 10:59, Bart Van Assche 写道: > On 1/14/24 22:18, Yu Kuai wrote: >> Can you take a look at my previous patset if you haven't? And it'll >> be great to hear from your comments. >> >> https://lore.kernel.org/all/20231021154806.4019417-1-yukuai1@huaweicloud.com/ >> > > Something is missing from the cover letter of that patch series: > measurements that show the impact of that patch series on the maximum > IOPS that can be achieved with the null_blk driver. I'm afraid that the > performance impact of that patch series will be larger than what is > acceptable. Hi, This version is just RFC, and is focusing on the method. I ran some tests on null_blk in my VM and didn't notice performace regression. My idea is that I already make this patchset complicated, and I'm looking for some comments for this patchset without spending too much time on this blindly. I'll provide null_blk tests result in the next version if anyone thinks the approch is acceptable: 1) add a new field 'available_tags' and update it in slow path, hence fast path hctx_may_queue() won't be affected. 2) delay tag sharing untill failed to get driver tag; 3) add a timer per shared tags to balance shared tags; Thanks, Kuai > > Thanks, > > Bart. > > . >