From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ilya Dryomov Subject: Re: [Ceph-qa] multiple BLK-MQ queues for Ceph's RADOS Block Device (RBD) and CephFS Date: Tue, 14 Jul 2020 23:16:28 +0200 Message-ID: References: Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Return-path: Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33552 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727981AbgGNVQZ (ORCPT ); Tue, 14 Jul 2020 17:16:25 -0400 Received: from mail-io1-xd43.google.com (mail-io1-xd43.google.com [IPv6:2607:f8b0:4864:20::d43]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 484F2C061755 for ; Tue, 14 Jul 2020 14:16:25 -0700 (PDT) Received: by mail-io1-xd43.google.com with SMTP id c16so18863170ioi.9 for ; Tue, 14 Jul 2020 14:16:25 -0700 (PDT) In-Reply-To: Sender: ceph-devel-owner@vger.kernel.org List-ID: To: Bobby Cc: dev , Ceph Development On Mon, Jul 13, 2020 at 8:40 PM Bobby wrote: > > > Hi, > > I have a question regarding support for multiple BLK-MQ queues for Ceph's= RADOS Block Device (RBD). The below given link says that the driver has be= en using the BLK-MQ interface for a while but not actually multiple queues = until now with having a queue per-CPU. A change to not hold onto caps that = aren't actually needed. These improvements and more can be found as part o= f the Ceph changes for Linux 5.7, which should be released as stable in ear= ly June. > > https://www.phoronix.com/scan.php?page=3Dnews_item&px=3DLinux-5.7-Ceph-Pe= rformance > > My question is: Is it possible that through Ceph FS (Filesystem in User S= pace) I can develop a multi-queue driver for Ceph? Asking because this way = I can avoid kernel space. (https://docs.ceph.com/docs/nautilus/start/quick-= cephfs/) [ trimming CCs to dev and ceph-devel ] Hi Bobby, I'm not sure what you mean by a "multi-queue driver for Ceph". blk-mq is the block layer framework, it has nothing to do with filesystems, whether local sitting on top of a block device (such as ext4 or XFS) or distributed sitting on top of a network stack (such as CephFS). Do you have a specific project in mind or are you just looking to make ceph-fuse faster? Thanks, Ilya