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 A94AAC0015E for ; Sun, 18 Jun 2023 20:58:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229545AbjFRU6M (ORCPT ); Sun, 18 Jun 2023 16:58:12 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56836 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229640AbjFRU6L (ORCPT ); Sun, 18 Jun 2023 16:58:11 -0400 Received: from mail-qt1-x833.google.com (mail-qt1-x833.google.com [IPv6:2607:f8b0:4864:20::833]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0FB63E51 for ; Sun, 18 Jun 2023 13:58:09 -0700 (PDT) Received: by mail-qt1-x833.google.com with SMTP id d75a77b69052e-3f9a81da5d7so251931cf.0 for ; Sun, 18 Jun 2023 13:58:09 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20221208; t=1687121888; x=1689713888; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:from:to:cc:subject:date :message-id:reply-to; bh=FZtyfCTAVMiPGQWHjgwoE9XDDUe5Zitl3naYIJu5u8M=; b=ZVT9TlvXekbzjsIk4FVN6w5b3V3bL2g07xM58CsOQEKlBliMaOMo4yZji4Q+4M2pTX PwOyYLy6AVqkAYYG8oZQzsoJ5wXO3fYU4dvuBveWcoPn/DBqA76dOm2wErETk5RMX4DF Pdjj7y7tVBfSg3bUPlVpNbbP9RKpJTFpWfMqG6NS8ogCoI9SFLLQjHjuiJCl9wmx/QMI sfudbAhw5Fv3ydEbSaSvd7K7sWgk9eaIp4KEVRbqeVVI+v27ojzRWzN3DHLLYoRPb3Uw 6IMcAn+rqIjZUCyYlDlj0BpHHcpwknOPBIBYMxSFkst2yjNHbhKR20MPChNpYuTjpIYD wwUg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1687121888; x=1689713888; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=FZtyfCTAVMiPGQWHjgwoE9XDDUe5Zitl3naYIJu5u8M=; b=DYCDVcSLYV1v7N+shgr9l5i+nzB5rx/K90VRN9eojaGmMU+I0E3pKppoV0OkfdOuEQ p6NtprayWUc3fLSGEY8N8FwoFHRMIIwXBGiFJ5Tcwu1+TGYNZYBQtbSIJuCil2vAGnLR tETd1rv0xIJ63DquQmwz7YC+5QbStLaO3dZ2eFWaac8OH1veLZtv7HSjnT5C0R9x/o+c 2aIml6qiK05xi8XKS/6j/GRGWaNizqVBtm3/48RQMAzl/dZdmroKg9xjwNDGZ2o2jsPm GKpAgTSVyRFMbtZiqnUrry/4qu3TR+8btn7cqRc81eY2Sv6A9UterjLfgsEBkmeqmi1c uhMA== X-Gm-Message-State: AC+VfDwU032XrMiueKDGMMoi9rN0JsdAM6pfdgy5elUXRsbDURSJkyGY Llokyw38xVBb/ZOYpJiOr1BPzaUxb7VsU48Yf8oO8Q== X-Google-Smtp-Source: ACHHUZ6ZDWbPtAWRuLjADFFa6FEUQ3GypTx245KPaUVC0BHZGX9Wd0LOXtVKSGnZtQDaYiPHdDlVEaUz0sYg2vTadSQ= X-Received: by 2002:a05:622a:20a:b0:3f9:a78f:c527 with SMTP id b10-20020a05622a020a00b003f9a78fc527mr291449qtx.21.1687121888063; Sun, 18 Jun 2023 13:58:08 -0700 (PDT) MIME-Version: 1.0 References: <178970b0-1539-8aac-76fd-972c6c46ec17@google.com> <20230614231758.GA1503611@dev-arch.thelio-3990X> <344a4da-3890-45fd-607e-b5f85ca6ad48@google.com> <20230615155059.GB3665766@dev-arch.thelio-3990X> <76b41825-30fa-b9e8-d043-2affcba24317@google.com> In-Reply-To: From: Yu Zhao Date: Sun, 18 Jun 2023 14:57:31 -0600 Message-ID: Subject: Re: [PATCH v2 07/23 replacement] mips: add pte_unmap() to balance pte_offset_map() To: Hugh Dickins , Nathan Chancellor , Thomas Bogendoerfer Cc: Andrew Morton , Mike Kravetz , Mike Rapoport , "Kirill A. Shutemov" , Matthew Wilcox , David Hildenbrand , Suren Baghdasaryan , Qi Zheng , Peter Zijlstra , Russell King , Catalin Marinas , Will Deacon , Geert Uytterhoeven , Greg Ungerer , Michal Simek , Helge Deller , John David Anglin , "Aneesh Kumar K.V" , Michael Ellerman , Alexandre Ghiti , Palmer Dabbelt , Heiko Carstens , Christian Borntraeger , Claudio Imbrenda , Alexander Gordeev , John Paul Adrian Glaubitz , "David S. Miller" , Chris Zankel , Max Filippov , x86@kernel.org, linux-arm-kernel@lists.infradead.org, linux-ia64@vger.kernel.org, linux-m68k@lists.linux-m68k.org, linux-parisc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org, linux-sh@vger.kernel.org, sparclinux@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-mips@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-sh@vger.kernel.org On Fri, Jun 16, 2023 at 9:54=E2=80=AFPM Yu Zhao wrote: > > On Thu, Jun 15, 2023 at 04:02:43PM -0700, Hugh Dickins wrote: > > To keep balance in future, __update_tlb() remember to pte_unmap() after > > pte_offset_map(). This is an odd case, since the caller has already do= ne > > pte_offset_map_lock(), then mips forgets the address and recalculates i= t; > > but my two naive attempts to clean that up did more harm than good. > > > > Tested-by: Nathan Chancellor > > Signed-off-by: Hugh Dickins > > FWIW: Tested-by: Yu Zhao > > There is another problem, likely caused by khugepaged, happened multiple = times. But I don't think it's related to your series, just FYI. > > Got mcheck at ffffffff81134ef0 > CPU: 3 PID: 36 Comm: khugepaged Not tainted 6.4.0-rc6-00049-g62d8779610= bb-dirty #1 ... > Kernel panic - not syncing: Caught Machine Check exception - caused by = multiple matching entries in the TLB. In case anyone plans to try to fix this - the problem goes back to at least 5.15 stable. My (educated) guess is that nobody complained about it because all the testing is done in QEMU, which does NOT detect conflicting TLBs. This means the verification of the fix would need to be on a real piece of h/w or an updated QEMU. In target/mips/tcg/sysemu/tlb_helper.c: static void r4k_fill_tlb(CPUMIPSState *env, int idx) { r4k_tlb_t *tlb; uint64_t mask =3D env->CP0_PageMask >> (TARGET_PAGE_BITS + 1); /* XXX: detect conflicting TLBs and raise a MCHECK exception when neede= d */ ...