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 X-Spam-Level: X-Spam-Status: No, score=-7.2 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4F477C433EF for ; Wed, 15 Sep 2021 13:15:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3C7AC6121E for ; Wed, 15 Sep 2021 13:15:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234205AbhIONQe (ORCPT ); Wed, 15 Sep 2021 09:16:34 -0400 Received: from smtp-out1.suse.de ([195.135.220.28]:58792 "EHLO smtp-out1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234083AbhIONQd (ORCPT ); Wed, 15 Sep 2021 09:16:33 -0400 Received: from relay2.suse.de (relay2.suse.de [149.44.160.134]) by smtp-out1.suse.de (Postfix) with ESMTP id 21FEB221F4; Wed, 15 Sep 2021 13:15:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_rsa; t=1631711713; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=rEF7u8XU7SpeSaF4r255WFI/LWFnrYPZGiAayeaOZJU=; b=PrXj/5CckEFQedXHwOTos5jEI+itNwZQiSUhAHss2DYyRC5jlpNe5mta4wc5NtVZlyV8X5 /k48GLs+GpZzuyeusScj6hz7Vj8JpPrWPXdbhXLSNwBgjpH+x/ZIDfhHNn8foLwXYKoJU0 SHyl70JOseJmjwLo5FRDAste27y6UsA= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_ed25519; t=1631711713; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=rEF7u8XU7SpeSaF4r255WFI/LWFnrYPZGiAayeaOZJU=; b=HLkXkMI0URAR8Q4SAWr96N9biMt2ZReC6q1ZjRa3DvNDCxEQ7Hx7gp9BBVHYmGe3Yo7qEd wm9EiT1jV5E/U5Dg== Received: from quack2.suse.cz (unknown [10.100.224.230]) by relay2.suse.de (Postfix) with ESMTP id 12F75A3B99; Wed, 15 Sep 2021 13:15:13 +0000 (UTC) Received: by quack2.suse.cz (Postfix, from userid 1000) id C673E1E4318; Wed, 15 Sep 2021 15:15:12 +0200 (CEST) Date: Wed, 15 Sep 2021 15:15:12 +0200 From: Jan Kara To: Michal =?iso-8859-1?Q?Koutn=FD?= Cc: Paolo Valente , Jan Kara , Jens Axboe , linux-block@vger.kernel.org Subject: Re: [PATCH 0/3 v2] bfq: Limit number of allocated scheduler tags per cgroup Message-ID: <20210915131512.GB6166@quack2.suse.cz> References: <20210715132047.20874-1-jack@suse.cz> <751F4AB5-1FDF-45B0-88E1-0C76ED1AAAD6@linaro.org> <20210831095930.GB17119@blackbody.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20210831095930.GB17119@blackbody.suse.cz> User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On Tue 31-08-21 11:59:30, Michal Koutný wrote: > Hello Paolo. > > On Fri, Aug 27, 2021 at 12:07:20PM +0200, Paolo Valente wrote: > > Before discussing your patches in detail, I need a little help on this > > point. You state that the number of scheduler tags must be larger > > than the number of device tags. So, I expected some of your patches > > to address somehow this issue, e.g., by increasing the number of > > scheduler tags. Yet I have not found such a change. Did I miss > > something? > > I believe Jan's conclusions so far are based on "manual" modifications > of available scheduler tags by /sys/block/$dev/queue/nr_requests. > Finding a good default value may be an additional change. Exactly. So far I was manually increasing nr_requests. I agree that improving the default nr_requests value selection would be desirable as well so that manual tuning is not needed. But for now I've left that aside. Honza -- Jan Kara SUSE Labs, CR