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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id BFA60CC6B2D for ; Wed, 14 Oct 2026 21:39:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=yfZ/FsY5Zh5zIE98xQp6NV9qIckj8O0+XPOxXg+eC7s=; b=o043TrDtFZq6lclu5Ye+tVrrwS sbBMcFKExDbK/3vanLfC1JJZBodCbkuE0wTi+qlCSXeUcOB9ZqgE9n1wE5obU3P6dV3+0op0F555v aB4W1Z2uhwu+Z1yNiIDeGcBAykwiMjYFdq6r8ECL6LTDGcl4MNCn1Lh6zS15M4xHQWD0oBpzPhQgM FwWdl4m6zOV7Qygi/SBNEjlbeznKg/FyvZx5rhog6v2Y1Ezl3CsaZKm6Xc7Vw5K18B74YmvNproqQ tuG266prgJUI0gjRI8oIcaUxbYSjIfBkyk50OW00XOpAsDqGCfEd0pNwRCj8xYIWtSES/7+ACwL8F 22eUHCQQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1xH6h3-0000000GMFh-0yyZ; Wed, 14 Oct 2026 21:39:25 +0000 Received: from sea.source.kernel.org ([172.234.252.31]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1xH6gz-0000000GMF2-1xsf for linux-nvme@lists.infradead.org; Wed, 14 Oct 2026 21:39:23 +0000 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by sea.source.kernel.org (Postfix) with ESMTP id EE20443D66; Wed, 14 Oct 2026 21:39:20 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7CD451F000C4; Wed, 14 Oct 2026 21:39:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1792013960; bh=yfZ/FsY5Zh5zIE98xQp6NV9qIckj8O0+XPOxXg+eC7s=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=HRCHauSgwJ/+0LsfAw1SACphQ9Kn9zODj961nCBEGV3/bMZDtKsi2rGRhU7tDMSC4 zXjZTwx6P3bv7dM2sLbW2w2Eu4X7AWVVRSN70mffrQhpCfaBRUhmzmrBnnq1UT3Ad+ sdFqv9lK/4YPubDzF1ZBrTc4iBwKBQVkEhtitkdWCDGeWsoygSExU1/8B8ATIw7fi2 OcjPxIKmVDBMwpeteOneHvhiUVdJcfLqy/A0HC+I0GH7C01JiQvD52c9C2IldfJ8DF 0gK1udx+3M2MAvlbMnvEQqvlFvz68IgsgdXakWqQqMasBApPcyiFKfRnEYjFQvAYVT g1auJ3Fe/9Uow== Date: Wed, 14 Oct 2026 15:39:18 -0600 From: Keith Busch To: Thomas Gleixner Cc: Bjorn Helgaas , Keith Busch , linux-nvme@lists.infradead.org, hch@lst.de, changfengnan@bytedance.com, linux-pci@vger.kernel.org, namjain@linux.microsoft.com, Luigi Rizzo Subject: Re: [RFC PATCH 2/3] PCI/MSI: Implement irq_mask_nowait() for MSI-x Message-ID: References: <20261014173106.GA1643226@bhelgaas> <878q40f0oa.ffs@fw13> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <878q40f0oa.ffs@fw13> X-BeenThere: linux-nvme@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "Linux-nvme" Errors-To: linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org On Wed, Oct 14, 2026 at 11:10:45PM +0200, Thomas Gleixner wrote: > On Wed, Oct 14 2026 at 12:31, Bjorn Helgaas wrote: > >> Skip the read-back that flushes the MSI-x mask write. Parent domains > >> that mask on behalf of PCI/MSI continue using their own irq_mask(). > >> > >> Signed-off-by: Keith Busch > > > > I assume Thomas will review/ack the pci/msi/ parts. > > Yes. I actually suggested that "nowait" mechanism to Keith at LPC. > > Though I hate the name of that callback because irq_mask() does not > really wait. It guarantees that the mask store has reached the device > which means that after that point no further interrupts will be sent by > the device (assuming sane hardware). That means it's a synchronous > operation which involves flushing the store, so maybe irq_mask_noflush() > or irq_mask_async() might be more accurate and descriptive. Right thank you, I misremembered your suggested name. I am totally fine with "noflush", and I've made that change in my local branch. I'll just wait a bit for any other feedback before the next version. > > Cc'd Luigi since I know he's interested in interrupt moderation in > > general. > > Correct. I'm curious whether the interrupt frequency based moderation > mechanism Luigi is proposing does solve the NVME issues as well or can > be combined with some device specific hint mechanism. > > That said, Luigi's approach should benefit from the "nowait" mechanism > as well. > > Luigi? > > Thanks, > > tglx