From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 4000C2BE641 for ; Mon, 24 Nov 2025 17:05:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764003907; cv=none; b=A0jFJrbM5MpySVBk0bcOsC/n5Hr74kSSTvSeG+Y0yZ1oijyOB4+wFYIp+CrgI/FNarbjfV3SyHXcW56DwYRkHbhGh6Quez0TXw2vZcu1MtMh5zJgmxIwcE4d3aiJlKZDl4plHA0EFGw91BvsKhEWuyv86wmF4Uz4D/bSoWUfPJE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764003907; c=relaxed/simple; bh=D3KrTWBY6jm2x9Hlo2t7wMeEpeX0KvUBsFsMbqIhc2o=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=XbPYP8TbR9xL2unoHlqjAkGanOUQBA6k2DigSnN67OpB24iZ/AIIvOUb+cjzoZhrqKiWIB87mjUwTnRAiO87++BsvXWEi5cbuHl1GOoqAnbAYCN5oGWJBJYa7841hOW8m1oWvMEDP6+tOeojID4kCT/8gWOreeBdYYwmaf3fEjI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=K+421HU7; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="K+421HU7" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 31DE1C4CEF1; Mon, 24 Nov 2025 17:05:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1764003906; bh=D3KrTWBY6jm2x9Hlo2t7wMeEpeX0KvUBsFsMbqIhc2o=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=K+421HU7jXKTq/rssClIwxW2gbgjEygTlAxVGxzWNzfE3uBv2/vh8nYpCKJqPhUif h+k5xJaRSeYq0Y4yt0OaMMTDiCTzySK7AC21uyjvR76Ts4TRrDiam7ViR0Uwuwop/o 1mlMGnNYVUN1lu29pzRqmRmjIhLbxBGvuWI8legg= Date: Mon, 24 Nov 2025 18:05:04 +0100 From: Greg KH To: Shrikanth Hegde Cc: linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, mingo@redhat.com, peterz@infradead.org, juri.lelli@redhat.com, vincent.guittot@linaro.org, tglx@linutronix.de, yury.norov@gmail.com, maddy@linux.ibm.com, srikar@linux.ibm.com, pbonzini@redhat.com, seanjc@google.com, kprateek.nayak@amd.com, vschneid@redhat.com, iii@linux.ibm.com, huschle@linux.ibm.com, rostedt@goodmis.org, dietmar.eggemann@arm.com, christophe.leroy@csgroup.eu Subject: Re: [PATCH 00/17] Paravirt CPUs and push task for less vCPU preemption Message-ID: <2025112454-phonics-crept-5b98@gregkh> References: <20251119124449.1149616-1-sshegde@linux.ibm.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20251119124449.1149616-1-sshegde@linux.ibm.com> On Wed, Nov 19, 2025 at 06:14:32PM +0530, Shrikanth Hegde wrote: > Detailed problem statement and some of the implementation choices were > discussed earlier[1]. > > [1]: https://lore.kernel.org/all/20250910174210.1969750-1-sshegde@linux.ibm.com/ > > This is likely the version which would be used for LPC2025 discussion on > this topic. Feel free to provide your suggestion and hoping for a solution > that works for different architectures and it's use cases. > > All the existing alternatives such as cpu hotplug, creating isolated > partitions etc break the user affinity. Since number of CPUs to use change > depending on the steal time, it is not driven by User. Hence it would be > wrong to break the affinity. This series allows if the task is pinned > only paravirt CPUs, it will continue running there. > > Changes compared v3[1]: There is no "v" for this series :(