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=-12.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham 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 82066C47082 for ; Wed, 9 Jun 2021 00:17:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6195761208 for ; Wed, 9 Jun 2021 00:17:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232437AbhFIASw (ORCPT ); Tue, 8 Jun 2021 20:18:52 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48320 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231186AbhFIASv (ORCPT ); Tue, 8 Jun 2021 20:18:51 -0400 Received: from mail-il1-x135.google.com (mail-il1-x135.google.com [IPv6:2607:f8b0:4864:20::135]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 75C90C061574 for ; Tue, 8 Jun 2021 17:16:58 -0700 (PDT) Received: by mail-il1-x135.google.com with SMTP id b5so22260474ilc.12 for ; Tue, 08 Jun 2021 17:16:58 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:cc; bh=Q7umJMxlcORXR8DXG5jeDR7TIw3EETGwHHTK3QtzcYo=; b=osmrq6EEKAmwXGO/ag5dY9/jajOyVwQXpRNKs8GMHVHuhmDzAL9cVQjwcfNeyNcXn0 IohPl1F9egwLhobBY44FPD/W6IiYAVhBueN86+qrXveAZpBrolRQFIR5hVqStziJ/4SZ 5uHkK9+YdImOVE0mM6m1zByJgRl/z/ykAruJ4QatYWyWL0/P4djpnlS2vMtRmmb4GmAo GFPwNrcvpN2oBBq92E6StvD+uYSaj1yGsKY9VnC5mJ+WRtKLog6bLjjKAHxIy8wXIKLF WlGinZaID9doaVmdBN2Sxji2g0zpq/MUuB0Nx5ngndjKogYUKmhYFUzertPiODPt2AN+ WMIA== 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:cc; bh=Q7umJMxlcORXR8DXG5jeDR7TIw3EETGwHHTK3QtzcYo=; b=ckf4baL58p17mjNUeG0i89iflnLrtQi7viiIR27hLLMkuCex0GP3MKIL8rMR2/OcMk tn2AAfRAQw/XVNpTepqAOZwAT4AUYV3QReUfHpsgfu0qfKjTK6SQp3teaFBEBCE4ScA6 JcRigedfC9EKLp4noqDsQPI2Y8DZ4sIR9GMxAWwh1DPgcT03Frpm95PxLQkLQ0WoduUX OfFd/c9R/ArNW44OIs/T56KAUg73aJuyhsMEqVGdY/6IhhwaWuJKJcyjHuY3pHE9IxYa nBUbfnOGEtIBFR9BfR51S0MpUFFTN5LQprPW3YpFtIfnMfJ5mvvR29vJ515TZdoV+0A7 5kHw== X-Gm-Message-State: AOAM53338Fbd1PrDPCXX0fZCq5Ua+p3JJup9LKe28oG9Fyca35e+ml8C gBFA43Ydu1ltIXsYX0NSQJJ97Rv83NXqVvXi3w== X-Received: by 2002:a05:6638:210d:: with SMTP id n13mt23313955jaj.7.1623197817102; Tue, 08 Jun 2021 17:16:57 -0700 (PDT) MIME-Version: 1.0 References: <20210608103359.84907-1-kernelfans@gmail.com> In-Reply-To: <20210608103359.84907-1-kernelfans@gmail.com> From: Pingfan Liu Date: Wed, 9 Jun 2021 08:16:46 +0800 Message-ID: Subject: Re: [PATCH] crash_core, vmcoreinfo: Append 'SECTION_SIZE_BITS' to vmcoreinfo Cc: Bhupesh Sharma , Dave Young , Baoquan He , Boris Petkov , Ingo Molnar , Thomas Gleixner , James Morse , Mark Rutland , Will Deacon , Catalin Marinas , Michael Ellerman , Paul Mackerras , Benjamin Herrenschmidt , Dave Anderson , linuxppc-dev , LKML , Kexec Mailing List , "maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)" , Linux ARM , k-hagio-ab@nec.com Content-Type: text/plain; charset="UTF-8" To: unlisted-recipients:; (no To-header on input) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Correct mail address of Kazuhito On Tue, Jun 8, 2021 at 6:34 PM Pingfan Liu wrote: > > As mentioned in kernel commit 1d50e5d0c505 ("crash_core, vmcoreinfo: > Append 'MAX_PHYSMEM_BITS' to vmcoreinfo"), SECTION_SIZE_BITS in the > formula: > #define SECTIONS_SHIFT (MAX_PHYSMEM_BITS - SECTION_SIZE_BITS) > > Besides SECTIONS_SHIFT, SECTION_SIZE_BITS is also used to calculate > PAGES_PER_SECTION in makedumpfile just like kernel. > > Unfortunately, this arch-dependent macro SECTION_SIZE_BITS changes, e.g. > recently in kernel commit f0b13ee23241 ("arm64/sparsemem: reduce > SECTION_SIZE_BITS"). But user space wants a stable interface to get this > info. Such info is impossible to be deduced from a crashdump vmcore. > Hence append SECTION_SIZE_BITS to vmcoreinfo. > > Signed-off-by: Pingfan Liu > Cc: Bhupesh Sharma > Cc: Kazuhito Hagio > Cc: Dave Young > Cc: Baoquan He > Cc: Boris Petkov > Cc: Ingo Molnar > Cc: Thomas Gleixner > Cc: James Morse > Cc: Mark Rutland > Cc: Will Deacon > Cc: Catalin Marinas > Cc: Michael Ellerman > Cc: Paul Mackerras > Cc: Benjamin Herrenschmidt > Cc: Dave Anderson > Cc: linuxppc-dev@lists.ozlabs.org > Cc: linux-kernel@vger.kernel.org > Cc: kexec@lists.infradead.org > Cc: x86@kernel.org > Cc: linux-arm-kernel@lists.infradead.org > --- > kernel/crash_core.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/kernel/crash_core.c b/kernel/crash_core.c > index 825284baaf46..684a6061a13a 100644 > --- a/kernel/crash_core.c > +++ b/kernel/crash_core.c > @@ -464,6 +464,7 @@ static int __init crash_save_vmcoreinfo_init(void) > VMCOREINFO_LENGTH(mem_section, NR_SECTION_ROOTS); > VMCOREINFO_STRUCT_SIZE(mem_section); > VMCOREINFO_OFFSET(mem_section, section_mem_map); > + VMCOREINFO_NUMBER(SECTION_SIZE_BITS); > VMCOREINFO_NUMBER(MAX_PHYSMEM_BITS); > #endif > VMCOREINFO_STRUCT_SIZE(page); > -- > 2.29.2 >