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 3255ACCFA13 for ; Fri, 1 May 2026 15:52:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=r4T7hthhrVBVsDKd2kUgCIwTC2O2XIM1vYjKWbZESpI=; b=kwgQIp08xfYR9n znQo7eUesFdPenMNkdXMZLWu7R8Rjgc3rxx0+txVQHSjVjLKPJG4H2cIM9EilqhsRWnAFM7jqR7g1 otuPPTt0ag9RE0nS/sxL+Vztk2YJxb/QrJGU+vUvrUqHpQ6/YYFR8EWmj36z8k4AKbAxHzrmQ8tHG 3hQKbdrg7X3VO+2jighSQTLBerDSU6MW4IfEiojVlth60fwkWpnPM+Gwq+V1+Q+K81fiyTe3ZXTBr qm7HrNeOGMbCdQS6tTOuURsa3JGCR1IbbU3RtkyPCEAwxiyE3muf5ORGd9XqIGsRbVlhrA8nYl+LK Qk/FqNw49gH4n6aY2F3A==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1wIqAB-00000007N3s-3O3c; Fri, 01 May 2026 15:52:23 +0000 Received: from tor.source.kernel.org ([172.105.4.254]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1wIqAA-00000007N3R-0zpE; Fri, 01 May 2026 15:52:22 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by tor.source.kernel.org (Postfix) with ESMTP id 5DF83600AE; Fri, 1 May 2026 15:52:21 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 578D9C2BCB4; Fri, 1 May 2026 15:52:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1777650741; bh=CmRbcbTi+OjVPZtnCXwufH2SPkRkS5oJkc2YfZ1djM0=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=IVDd9j10pzEBSdRC4+QeFj4BgrGtGegXqADT53FcQUjMhslsOR/0b8M/SeBRUjbiL U2fYt86IaWaPqn4mV1onqa61I1SUk7HLNDW/omvLoBf0BH4n82Nt8SShUszHOEgWX+ Yg2s+/jyz3VDnqKEVso8YuKRhMIWmw5AZKuu313vA5DlmyJ/Rx3fmNczFEGG/bRD5C eqUXB71O0/nCiiPJ8qZcNkawkQKohpdSSJ4uA0FZNvaLfCO6RUdrocyE/W1A7fSAIz Hbt9kjA297YFDx/3kqUo5yAmQtYP02v7yShDf43ds+6qzWhvd82x48N7/jTN1fhgjc 65/sBiyDMsG6w== Date: Fri, 1 May 2026 16:52:12 +0100 From: Lorenzo Stoakes To: "Barry Song (Xiaomi)" Cc: Matthew Wilcox , akpm@linux-foundation.org, linux-mm@kvack.org, david@kernel.org, liam@infradead.org, vbabka@kernel.org, rppt@kernel.org, surenb@google.com, mhocko@suse.com, jack@suse.cz, pfalcato@suse.de, wanglian@kylinos.cn, chentao@kylinos.cn, lianux.mm@gmail.com, kunwu.chan@gmail.com, liyangouwen1@oppo.com, chrisl@kernel.org, kasong@tencent.com, shikemeng@huaweicloud.com, nphamcs@gmail.com, bhe@redhat.com, youngjun.park@lge.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, loongarch@lists.linux.dev, linuxppc-dev@lists.ozlabs.org, linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org Subject: Re: [PATCH v2 0/5] mm: reduce mmap_lock contention and improve page fault performance Message-ID: References: <20260430040427.4672-1-baohua@kernel.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org On Thu, Apr 30, 2026 at 01:37:14PM +0100, Matthew Wilcox wrote: > On Thu, Apr 30, 2026 at 12:04:22PM +0800, Barry Song (Xiaomi) wrote: > > (1) If we need to wait for I/O completion, we still drop the per-VMA lock, as > > current page fault handling already does. Holding it for too long may introduce > > various priority inversion issues on mobile devices. After I/O completes, we > > retry the page fault with the per-VMA lock, rather than falling back to > > mmap_lock. > > You're going to have to do better than that. You know I hate the > additional complexity you're adding. You need to explain why my idea of > ripping out all the complexity now that we have per-VMA locks doesn't > work. After a brief eyeball I share Matthew's assessment, I really don't like this series, it's piling on complexity for what seem like niche cases. We already have enough weirdness in fault code honestly. Let's maybe discuss at LSF if you're attending? I will try to have a more thorough look through when I get a chance. Thanks, Lorenzo _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv