From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wm1-f54.google.com (mail-wm1-f54.google.com [209.85.128.54]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 82C8964E for ; Wed, 24 Jan 2024 00:24:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.54 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706055882; cv=none; b=qKHx6DIkGwPkDWYKfYEW+orlZ0MkuESMUR8Qt4TG8ZixT3CDz95Q7s7MZQ/3LixH++I6x+2scJI9+Gvx0UolXt5GVv1ONI9rSTC3vRQCJ9pjS9dJkAme5+B+YbtYciuuNfbh1v7P6vzTdFKc694fz003XnAOyRZ/BGT44d7ert8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706055882; c=relaxed/simple; bh=hMh6ehSMtCLiTnXPJTwHRtndnydv9lJWmV6MQHsynhs=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=YPshepfKK05hx0WAX+eMHtkR1qO3vK04R05LMrVzBhiHg9MvoCtzcoZI6+3VF3eB4VMik7iNBxxN8HtvAnoj+hnn06RQCigz6ntStXvD0HVfD5zSEAC515AFagsQL1jXF6HmpfVWMHMjfPygap14hIrQ0E1TGjx0a/dkS3i2EoY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=layalina.io; spf=pass smtp.mailfrom=layalina.io; dkim=pass (2048-bit key) header.d=layalina-io.20230601.gappssmtp.com header.i=@layalina-io.20230601.gappssmtp.com header.b=GD8m5pAf; arc=none smtp.client-ip=209.85.128.54 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=layalina.io Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=layalina.io Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=layalina-io.20230601.gappssmtp.com header.i=@layalina-io.20230601.gappssmtp.com header.b="GD8m5pAf" Received: by mail-wm1-f54.google.com with SMTP id 5b1f17b1804b1-40eb2f392f0so16868895e9.1 for ; Tue, 23 Jan 2024 16:24:40 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=layalina-io.20230601.gappssmtp.com; s=20230601; t=1706055878; x=1706660678; darn=vger.kernel.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=oYTN8ome+CxuG7BZfLTx74gUUZSxMsFlzHcqYkFKxT8=; b=GD8m5pAfyOo9iUby3bTRSx21BPUEfdEbVbNqKmiJsALBZAcjwokmC89H0HsCihCPlX 7MniI/ulDEy1YhUuIj1XNvH0AGF4+Bu6vSjAbwa912pvvcBmQEXijUtIVAYvuecjdaCB 7MJB/GEcFJZcooXc4rLHmWFe71T6qbSKBXIafjhP+Km3Lqn88mBfTVisZL9xItVtm6TH Z8PUy5cuTuTukSRxqawi8kWxjGeL/aSYwaDnkRMxEL1A8qp4Wo2X8Jxux2BR6TunLWu+ /WRK4a0WxKXWjaxjovMqPMfs880PXhf4pls+5GdoTU6BAVShOpLflY21POjzSjGlY5A0 7NIg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1706055878; x=1706660678; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=oYTN8ome+CxuG7BZfLTx74gUUZSxMsFlzHcqYkFKxT8=; b=IVsEQfM1qDiM786RGjrKC2Lz13pHU3brlZZ3ovJOMc2suGMBFgLELvCD49gzX3Lvye APVu/PDbqOoAl4a5gf9ab0dNxxYacHITYLO1sXqzQfiCmzn9W1gp80j4E/uD3I6+LD7L WgM9s9Xt9dBHXl7j6XfZDBXZF7M12OZhouanGQJfPlJTW73Yq8+pzelViHr81cySu16W 7NtyMdh8vQdFRB5M264W/SQZErHGflrnuQpyy1nRT8rzL2NtPrsMCtTo3lLERS6VbIAf XLh0XqZG7jIB+gxhXuX4tVNaZ6mwmXUakRRT5loaJlqHes5An30NFPGUiUFu1RBC9ZDW 0JAw== X-Gm-Message-State: AOJu0YyQSsdZXwPmf7VHAVPS9bdtCizFnyPhJ5n1ZXuDYGI8vWYqTNVt NYGGhjDgLPsKFaJSknvFdtbqk+tcinPOpPLci+e808EYvc8jkMXxcukQNDbFG60= X-Google-Smtp-Source: AGHT+IEQEHnFx8D7dWd7qppBAry9oTyW6DVU6m4DstaCMTezb1yu1bJDpuzDp/n0gGRM1R0enN1Hmg== X-Received: by 2002:a05:600c:2203:b0:40e:869b:4c12 with SMTP id z3-20020a05600c220300b0040e869b4c12mr568787wml.162.1706055878546; Tue, 23 Jan 2024 16:24:38 -0800 (PST) Received: from airbuntu ([213.122.231.14]) by smtp.gmail.com with ESMTPSA id f6-20020a05600c154600b0040e880ac6ecsm24156066wmg.35.2024.01.23.16.24.37 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 23 Jan 2024 16:24:37 -0800 (PST) Date: Wed, 24 Jan 2024 00:24:36 +0000 From: Qais Yousef To: Jens Axboe Cc: Christoph Hellwig , Ingo Molnar , Peter Zijlstra , Vincent Guittot , Dietmar Eggemann , linux-kernel@vger.kernel.org, linux-block@vger.kernel.org, Sudeep Holla , Wei Wang , Jaegeuk Kim , Bart Van Assche Subject: Re: [PATCH] block/blk-mq: Don't complete locally if capacities are different Message-ID: <20240124002436.dj5lpjpdc3uttbx4@airbuntu> References: <20240122224220.1206234-1-qyousef@layalina.io> Precedence: bulk X-Mailing-List: linux-block@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: On 01/23/24 08:58, Jens Axboe wrote: > On 1/23/24 1:47 AM, Christoph Hellwig wrote: > > On Mon, Jan 22, 2024 at 10:42:20PM +0000, Qais Yousef wrote: > >> The logic in blk_mq_complete_need_ipi() assumes SMP systems where all > >> CPUs have equal capacities > > > > What is a capacity here? > > It seems to be the chosen word to describe the performance potential of > the core in question, we use it elsewhere in the kernel. But yes, could > do with a bit more of an explanation. Is referring to it as compute capacity makes it clearer? Sorry I thought that's a common term. > > >> + return arch_scale_cpu_capacity(this_cpu) >= arch_scale_cpu_capacity(that_cpu); > > > > oerly long line here. This is consistent with similar long lines in the same file and it's more readable as one line. checkpatch doesn't complain about this being long; I think they look for 100 or 120 now. This is 86. > > > > Also pleas split patches for different subsystems. > > Yes please, the sched/topology thing should be a separate prep patch. Okay. I thought the norm to keep such small patches self contained as adding dead code followed by a one liner isn't always seen as better. But a split it is :) I'll give the sched/arm folks time to have a look before I post a new version. Thanks! -- Qais Yousef