From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5EA85C4332F for ; Mon, 25 Apr 2022 13:22:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242004AbiDYNZr (ORCPT ); Mon, 25 Apr 2022 09:25:47 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55884 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241993AbiDYNZn (ORCPT ); Mon, 25 Apr 2022 09:25:43 -0400 Received: from fieldses.org (fieldses.org [IPv6:2600:3c00:e000:2f7::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 81C83366A2 for ; Mon, 25 Apr 2022 06:22:33 -0700 (PDT) Received: by fieldses.org (Postfix, from userid 2815) id 9571B6801; Mon, 25 Apr 2022 09:22:32 -0400 (EDT) DKIM-Filter: OpenDKIM Filter v2.11.0 fieldses.org 9571B6801 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fieldses.org; s=default; t=1650892952; bh=roKnXHrl6Kvns7HBwZTmsw7rJ2jxtvyuWV1qLI29uCs=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=uLIMvoG0kjm0ScmFclKEgWKXvRt3KAPlzZu0arbJKk1Ln9YT1t8U8HS7E8c4z1keQ B3psPV9R5fxgOwwDJsYqZ26OaoYN4ZejxwP5WBopc1CQJ6u58BzAB3b/go0GkZ8gvz XSh/qKiQYJEcA6cVX5olb7S0/wHWRbh8oaEiMQ5I= Date: Mon, 25 Apr 2022 09:22:32 -0400 From: "J. Bruce Fields" To: Daire Byrne Cc: NeilBrown , Patrick Goetz , linux-nfs Subject: Re: parallel file create rates (+high latency) Message-ID: <20220425132232.GA24825@fieldses.org> References: <20220125212055.GB17638@fieldses.org> <164315533676.5493.13243313269022942124@noble.neil.brown.name> <20220126025722.GD17638@fieldses.org> <20220211155949.GA4941@fieldses.org> <164517040900.10228.8956772146017892417@noble.neil.brown.name> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org On Mon, Apr 25, 2022 at 02:00:32PM +0100, Daire Byrne wrote: > On Mon, 21 Feb 2022 at 13:59, Daire Byrne wrote: > > > > On Fri, 18 Feb 2022 at 07:46, NeilBrown wrote: > > > I've ported it to mainline without much trouble. I started some simple > > > testing (parallel create/delete of the same file) and hit a bug quite > > > easily. I fixed that (eventually) and then tried with more than 1 CPU, > > > and hit another bug. But then it was quitting time. If I can get rid > > > of all the easy to find bugs, I'll post it with a CC to you, and you can > > > find some more for me! > > > > That would be awesome! I have a real world production case for this > > and it's a pretty heavy workload. If that doesn't shake out any bugs, > > nothing will. > > > > The only caveat being that it will likely be restricted to NFSv3 > > testing due to the concurrency limitations with NFSv4.1+ (from the > > other thread). > > > > Daire > > Just to follow up on this again - I have been using Neil's patch for > parallel file creates (thanks!) but I'm a bit confused as to why it > doesn't seem to help in my NFS re-export case. > > With the patch, I can achieve much higher parallel (multi process) > creates directly on my re-export server to a high latency remote > server mount, but when I re-export that to multiple clients, the > aggregate create rate again degrades to that which we might expect > either without the patch or if there was only one process creating the > files in sequence. > > My assumption was that the nfsd threads of the re-export server would > act as multiple independent processes and it's clients would be spread > across them such that they would also benefit from the parallel > creates patch on the re-export server. So I expected many clients > creating files in the same directory would achieve much higher > aggregate performance. That's the idea. I've lost track, where's the latest version of Neil's patch? --b. > > Am I missing some other interaction here that limits parallel > performance in my unusual re-export case? > > Cheers, > > Daire