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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 75BB3C04A6A for ; Fri, 4 Aug 2023 19:14:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229613AbjHDTOW (ORCPT ); Fri, 4 Aug 2023 15:14:22 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46836 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229488AbjHDTOT (ORCPT ); Fri, 4 Aug 2023 15:14:19 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D566CB9; Fri, 4 Aug 2023 12:14:18 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 735E562101; Fri, 4 Aug 2023 19:14:18 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 18C65C433C8; Fri, 4 Aug 2023 19:14:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1691176457; bh=KjLfStABFwUIAtuSAKNcnmOi2LteNNPlPp20ShgMzp4=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=Z0eePU9NC4Pz6n6vXCNvjXjwlqXDzzzr5i3qU2pMQKHmkgb5AhlUyg9FUUtR84vnj Zhk+jFYTAa/8XPVFoOiFEMxePF2hfUOKoJRQWf4aPeUTeLUzOv9oQhLUykgZa02sUW i8K5cksG4rlxLiAtQeTF7k4fI/GPmi0vCP1n8tWY= Date: Fri, 4 Aug 2023 12:14:16 -0700 From: Andrew Morton To: Suren Baghdasaryan Cc: torvalds@linux-foundation.org, jannh@google.com, willy@infradead.org, liam.howlett@oracle.com, david@redhat.com, peterx@redhat.com, ldufour@linux.ibm.com, vbabka@suse.cz, michel@lespinasse.org, jglisse@google.com, mhocko@suse.com, hannes@cmpxchg.org, dave@stgolabs.net, hughd@google.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, stable@vger.kernel.org, kernel-team@android.com, Linus Torvalds Subject: Re: [PATCH v4 1/6] mm: enable page walking API to lock vmas during the walk Message-Id: <20230804121416.533bb81336ded8f170da097e@linux-foundation.org> In-Reply-To: <20230804152724.3090321-2-surenb@google.com> References: <20230804152724.3090321-1-surenb@google.com> <20230804152724.3090321-2-surenb@google.com> X-Mailer: Sylpheed 3.8.0beta1 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 4 Aug 2023 08:27:19 -0700 Suren Baghdasaryan wrote: > walk_page_range() and friends often operate under write-locked mmap_lock. > With introduction of vma locks, the vmas have to be locked as well > during such walks to prevent concurrent page faults in these areas. > Add an additional member to mm_walk_ops to indicate locking requirements > for the walk. > > ... > > 18 files changed, 100 insertions(+), 20 deletions(-) > That's a big patch for a -stable backport. Presumably the various -stable maintainers will be wondering why we're doing this. But, as is so often the case, the changelog fails to describe any user-visible effects of the change. Please send this info and I'll add it to the changelog.