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 647D6EA813A for ; Tue, 10 Feb 2026 16:01:31 +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=6MdSVXl8RWks7nPV1PzvzGPfJDC4ruADqbIx9uS/avo=; b=p4En2bRTkNAN1A6kCM9l8ZnPiF w0ianuR3xbojLCpIJXTMZF0IPIoRUU6Ghav/aknmk7ebewyfjZN22PHTht0TXwZz47a9WnRe8TxAq Ry04wM2FrROqKo/cf0LtwRhwt5QYCAp/szLLuM9rH7ObGFqAU4C1KVvIRFm0UvKiF1heR5F03uOyA I8xPirw5GkViJj4oSkIHZ0DJpZUis39PHHwXxgv3s3gMMmi/rksQOFJMUEjHUZbcicJsSUmpqR/fY Hy1zQL+PSN0JnOmoV4f0/b8afwE+DuiMp6KeHBE9WTMsbmxsL8Wej0ywxbqdqVHvDR+o2BxHhA5hj ClyozJnA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vpqB3-0000000HB2F-1IPV; Tue, 10 Feb 2026 16:01:25 +0000 Received: from sea.source.kernel.org ([172.234.252.31]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1vpqAw-0000000HB1f-0xcn; Tue, 10 Feb 2026 16:01:23 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sea.source.kernel.org (Postfix) with ESMTP id 2910C439AA; Tue, 10 Feb 2026 16:01:17 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4F983C19421; Tue, 10 Feb 2026 16:01:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1770739277; bh=K3DXxvJ6FVQs/z6PXfq5PjWLrYk64mlcmilSRWH8Gu4=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=tSIqE/py5qSrzsPCv9NZ7D+h2TqKee2r1uwzqr8SGBAsPOR1LNl7i1WAWZFUznuh/ JsADInzYEHPuzgK2IYzDXF/lGjtM6mQWOIOGC9XLlsoWvtABRGd6cqFiO7/E0ED2wj Xf2fQxLLWyO5mvtbNVMgp0LDP+dcFrscctWr1y+rhydyw6ZVu6RNcc6NJ7jM5Z4Ez/ 5SotcOGMA8of/XN/+gPWNZh/3EI9MkvAD52KAk0hyAuhTuYVWKwdVKtwYK+IIkly4U 0RZ4dSJCZn6VWxsTeIE9RtlsHVVCBbTVJUGH2OPZsn2jxYPOqm5xZAgS3hkvHxOgGT zlF/BMg69MLXg== Date: Tue, 10 Feb 2026 09:01:14 -0700 From: Keith Busch To: Christoph Hellwig Cc: Yu Kuai , axboe@kernel.dk, sagi@grimberg.me, sven@kernel.org, j@jannau.net, linux-block@vger.kernel.org, linux-nvme@lists.infradead.org, tj@kernel.org, nilay@linux.ibm.com, ming.lei@redhat.com, neal@gompa.dev, asahi@lists.linux.dev, linux-arm-kernel@lists.infradead.org, Daniel Wagner Subject: Re: [PATCH 3/4] nvme-apple: move blk_mq_update_nr_hw_queues after nvme_unfreeze Message-ID: References: <20260209082953.3053721-1-yukuai@fnnas.com> <20260209082953.3053721-4-yukuai@fnnas.com> <20260209145832.GC18315@lst.de> <20260210154108.GB2484@lst.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260210154108.GB2484@lst.de> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260210_080118_284981_AA4E4CDE X-CRM114-Status: GOOD ( 19.01 ) X-BeenThere: linux-arm-kernel@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-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Tue, Feb 10, 2026 at 04:41:08PM +0100, Christoph Hellwig wrote: > On Tue, Feb 10, 2026 at 08:09:08AM -0700, Keith Busch wrote: > > If you leave the queue quiesced, pending IO will form requests that are > > entered and waiting in the block layer. You can't freeze a queue with > > entered requests. > > > > We unquiesce first to flush any pending IO that had entered during the > > prior reset. It's not the best way to handle this situation. It would be > > smarter to steal the bio's from all the entered requests, then end those > > requests, then resubmit the bios after the hw queues are initialized. We > > don't do that because no one's really complained, probably because the > > queue counts don't usually change after a reset. > > FYI, Daniel Wagner had been thinking about doing this reinsert for > something (I forgot what exactly), and this kind of reinserting from > kblockd would also finally make REQ_NOWAIT practically useful for > file system initiated writes. So I hope we can eventually get to it, > and it should help to sort out various problems. I took a moment to craft a test by modifying the poll_queues parameter at runtime, say from 1 -> 0, then start a controller reset. Turns out the driver is a bit broken here. A hipri job will poll a non-polled queue after the reset, causing a double completion with the now irq driven queue, and the entire blk-mq map is messed up, too. Oops!