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 X-Spam-Level: X-Spam-Status: No, score=-4.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2BFFEC433E0 for ; Sat, 8 Aug 2020 04:41:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EFC59221E5 for ; Sat, 8 Aug 2020 04:41:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1596861692; bh=h3Li9pyb+7kB9jHKMkng5i4YmeqsWOhPrlzbKUegzlg=; h=References:In-Reply-To:From:Date:Subject:To:Cc:List-ID:From; b=D2FszvPt815W5aPZ8RYYb+QkqIkOfp95ahBR01xB4BVicVW/Eh2sx6DJMAF7qjQNC 3lBxWGAKH+qFcOtDyEisiei6e9clc474xKAyMWDExbY5PMBxEU+XO0vUsYnxlPKgX+ g/ylBWTFyJwJtuB/5LB+fQA23Ofu3GCZ18s4PJtE= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725294AbgHHElb (ORCPT ); Sat, 8 Aug 2020 00:41:31 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34776 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725267AbgHHElb (ORCPT ); Sat, 8 Aug 2020 00:41:31 -0400 Received: from mail-ej1-x644.google.com (mail-ej1-x644.google.com [IPv6:2a00:1450:4864:20::644]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B4A7CC061756 for ; Fri, 7 Aug 2020 21:41:30 -0700 (PDT) Received: by mail-ej1-x644.google.com with SMTP id f24so4112049ejx.6 for ; Fri, 07 Aug 2020 21:41:30 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=4c2A3vRrijfjepyTUsYsz/g1xu4ckn8h3voqWBmATys=; b=dRVV0FqgTCJe9pp6Q6oXl7nMcd3bjCnGyOPITp5wKM0EJWmMJjovnFBJCHWkOLcV+w XVgeM/6dMv69ZS7jN9DSRGlr2pIwEAY6oHMyJjZhsMJkq9xDvdD+i6Fxt4IFfInOXZKx bcyOlkVn/YzPjQiARHhAdkHvtWIVdCQceorew= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=4c2A3vRrijfjepyTUsYsz/g1xu4ckn8h3voqWBmATys=; b=REaZAgsmxRqSKWz6CuXOjbKN9cywNRc1kOoOwSjtGuvEjFg/6Pa2MhlXQViE2Y63Pn aShLQCHT0bly7IuF/HpbDjUWEF+d9cPM+RwBE7+vuoip2FGCXqk5wbJLXmk28c5nDl39 Y+upWc9i1jWeppO0giHj+LeuLAarHrqJJET+Wtg8FNsG0CXJlBQ2Nw8HQNcUH5n35LES oeKSg6wm6X/UC8w7lcdZ2IsQUm2CIonOEGV+b6VM426FX26Ri4E6vtXsypBqlz384tuF ENQfgmT43bgLnKj1hmzNM4irMtI/qIxyA0cgmX6AefIooHps691mMbDJ8Jpbun/T/FwA UtyQ== X-Gm-Message-State: AOAM533Xz+NbCCSFGwBL/LJKW+nDvHUT+bIhzZ9mH0y+to2zLmuK5rZ+ ZJKbI8dGLKeGQFbA+eWtBqCgtzw2BJkPwQ== X-Google-Smtp-Source: ABdhPJxrziBOlyDq3vgWDyh9I/isapnf0ZhdYkcHSwjaEGxhoS8grxxN/zAXzLSGTv0Q3Z3+g7pAeQ== X-Received: by 2002:a17:906:a3d5:: with SMTP id ca21mr12286080ejb.453.1596861688949; Fri, 07 Aug 2020 21:41:28 -0700 (PDT) Received: from mail-wr1-f41.google.com (mail-wr1-f41.google.com. [209.85.221.41]) by smtp.gmail.com with ESMTPSA id v22sm6611641edq.35.2020.08.07.21.41.28 for (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 07 Aug 2020 21:41:28 -0700 (PDT) Received: by mail-wr1-f41.google.com with SMTP id c15so3359293wrs.11 for ; Fri, 07 Aug 2020 21:41:28 -0700 (PDT) X-Received: by 2002:a2e:2e04:: with SMTP id u4mr7220109lju.102.1596861246750; Fri, 07 Aug 2020 21:34:06 -0700 (PDT) MIME-Version: 1.0 References: <20200806231643.a2711a608dd0f18bff2caf2b@linux-foundation.org> <20200807061706.unk5_0KtC%akpm@linux-foundation.org> In-Reply-To: From: Linus Torvalds Date: Fri, 7 Aug 2020 21:33:50 -0700 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [patch 001/163] mm/memory.c: avoid access flag update TLB flush for retried page fault To: Yang Shi Cc: Andrew Morton , Catalin Marinas , Johannes Weiner , Hillf Danton , Hugh Dickins , Josef Bacik , "Kirill A . Shutemov" , Linux-MM , mm-commits@vger.kernel.org, stable , Will Deacon , Matthew Wilcox , Yu Xu , Yang Shi Content-Type: text/plain; charset="UTF-8" Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org On Fri, Aug 7, 2020 at 1:53 PM Yang Shi wrote: > > I'm supposed Catalin would submit his proposal (flush local TLB for > spurious TLB fault on ARM) for this specific regression per the > discussion, right? I think arm64 should do that regardless, yes. But I would also be ok with a version that does the FAULT_FLAG_TRIED testing, but does it only for that spurious TLB flushing. This "let's not update the page tables at all" is wrong, when the only problem was the TLB flushing. So changing the current (but quesitonable) if (vmf->flags & FAULT_FLAG_WRITE) flush_tlb_fix_spurious_fault(vmf->vma, vmf->address); to be if (vmf->flags & (FAULT_FLAG_WRITE | FAULT_FLAG_TRIED)) flush_tlb_fix_spurious_fault(vmf->vma, vmf->address); would be fine. But this patch that changes any semantics outside just the flushin gis a complete no-no. Linus 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 X-Spam-Level: X-Spam-Status: No, score=-4.1 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 338A8C433DF for ; Sat, 8 Aug 2020 04:34:15 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 9D2FE221E5 for ; Sat, 8 Aug 2020 04:34:14 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="dRVV0Fqg" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9D2FE221E5 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id E3A066B0005; Sat, 8 Aug 2020 00:34:13 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id DE9166B0006; Sat, 8 Aug 2020 00:34:13 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id CD8166B0007; Sat, 8 Aug 2020 00:34:13 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0203.hostedemail.com [216.40.44.203]) by kanga.kvack.org (Postfix) with ESMTP id B77266B0005 for ; Sat, 8 Aug 2020 00:34:13 -0400 (EDT) Received: from smtpin16.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 57A46181AEF09 for ; Sat, 8 Aug 2020 04:34:13 +0000 (UTC) X-FDA: 77126134386.16.pigs38_1805b5f26fc6 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin16.hostedemail.com (Postfix) with ESMTP id 26CCA100E6903 for ; Sat, 8 Aug 2020 04:34:13 +0000 (UTC) X-HE-Tag: pigs38_1805b5f26fc6 X-Filterd-Recvd-Size: 4814 Received: from mail-lf1-f68.google.com (mail-lf1-f68.google.com [209.85.167.68]) by imf10.hostedemail.com (Postfix) with ESMTP for ; Sat, 8 Aug 2020 04:34:12 +0000 (UTC) Received: by mail-lf1-f68.google.com with SMTP id i80so2022702lfi.13 for ; Fri, 07 Aug 2020 21:34:12 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=4c2A3vRrijfjepyTUsYsz/g1xu4ckn8h3voqWBmATys=; b=dRVV0FqgTCJe9pp6Q6oXl7nMcd3bjCnGyOPITp5wKM0EJWmMJjovnFBJCHWkOLcV+w XVgeM/6dMv69ZS7jN9DSRGlr2pIwEAY6oHMyJjZhsMJkq9xDvdD+i6Fxt4IFfInOXZKx bcyOlkVn/YzPjQiARHhAdkHvtWIVdCQceorew= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=4c2A3vRrijfjepyTUsYsz/g1xu4ckn8h3voqWBmATys=; b=Lxg6QNat1N2iLoSAnDG5QdURLLumWwtHKiyucdfC1ULYCJALHJcxfyk9u9S/LbTlWe donP6Z3Jtii5evRKPuwS5BzZaVNkmO5E7kQuKez8gzwEIKjBgvqkXc68DmOmt9NMIRxG 0qGIEyuKsGi+WN3VFheGSSofovitSpLC3O1QaiiQuLTZq+GWrfq3GivSjajzns/SK6q4 +dFA8mF2FjM1XhX0TqoDUhZTW3553nokw9GiAirpwC+oPGpartZFWps+kGUBcVfoX9/3 /g6HN0F67zJvzhnKgP8jxiE4HSlVhWSTnVfvjT8Lc6D9uDD+XUg6q/4U5ohPR3zMC4yA gqGA== X-Gm-Message-State: AOAM533vz7ChRC6v4mzZsDrludA2EM/+K305PQIHPCfMJFC5e/Vx2Hje YSNw2hDlv8137O4sx9yexn+vuXE2wSuczw== X-Google-Smtp-Source: ABdhPJzXiyECULt+rn7IUdQpmxcZJcFtrCa0Z1+LAlcb+PBjuw1vlLAaFpFl7UjOSpcyMIuX/snRdw== X-Received: by 2002:a19:414b:: with SMTP id o72mr8070964lfa.86.1596861250079; Fri, 07 Aug 2020 21:34:10 -0700 (PDT) Received: from mail-lj1-f172.google.com (mail-lj1-f172.google.com. [209.85.208.172]) by smtp.gmail.com with ESMTPSA id m20sm5491117lfb.72.2020.08.07.21.34.07 for (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 07 Aug 2020 21:34:07 -0700 (PDT) Received: by mail-lj1-f172.google.com with SMTP id t6so4246033ljk.9 for ; Fri, 07 Aug 2020 21:34:07 -0700 (PDT) X-Received: by 2002:a2e:2e04:: with SMTP id u4mr7220109lju.102.1596861246750; Fri, 07 Aug 2020 21:34:06 -0700 (PDT) MIME-Version: 1.0 References: <20200806231643.a2711a608dd0f18bff2caf2b@linux-foundation.org> <20200807061706.unk5_0KtC%akpm@linux-foundation.org> In-Reply-To: From: Linus Torvalds Date: Fri, 7 Aug 2020 21:33:50 -0700 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [patch 001/163] mm/memory.c: avoid access flag update TLB flush for retried page fault To: Yang Shi Cc: Andrew Morton , Catalin Marinas , Johannes Weiner , Hillf Danton , Hugh Dickins , Josef Bacik , "Kirill A . Shutemov" , Linux-MM , mm-commits@vger.kernel.org, stable , Will Deacon , Matthew Wilcox , Yu Xu , Yang Shi Content-Type: text/plain; charset="UTF-8" X-Rspamd-Queue-Id: 26CCA100E6903 X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam02 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Fri, Aug 7, 2020 at 1:53 PM Yang Shi wrote: > > I'm supposed Catalin would submit his proposal (flush local TLB for > spurious TLB fault on ARM) for this specific regression per the > discussion, right? I think arm64 should do that regardless, yes. But I would also be ok with a version that does the FAULT_FLAG_TRIED testing, but does it only for that spurious TLB flushing. This "let's not update the page tables at all" is wrong, when the only problem was the TLB flushing. So changing the current (but quesitonable) if (vmf->flags & FAULT_FLAG_WRITE) flush_tlb_fix_spurious_fault(vmf->vma, vmf->address); to be if (vmf->flags & (FAULT_FLAG_WRITE | FAULT_FLAG_TRIED)) flush_tlb_fix_spurious_fault(vmf->vma, vmf->address); would be fine. But this patch that changes any semantics outside just the flushin gis a complete no-no. Linus