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 0B842C19F28 for ; Wed, 3 Aug 2022 09:45:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237495AbiHCJpI (ORCPT ); Wed, 3 Aug 2022 05:45:08 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56466 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237460AbiHCJo4 (ORCPT ); Wed, 3 Aug 2022 05:44:56 -0400 Received: from mail-yw1-x112a.google.com (mail-yw1-x112a.google.com [IPv6:2607:f8b0:4864:20::112a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8E8023DF04 for ; Wed, 3 Aug 2022 02:44:55 -0700 (PDT) Received: by mail-yw1-x112a.google.com with SMTP id 00721157ae682-3246910dac3so113768437b3.12 for ; Wed, 03 Aug 2022 02:44:55 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:from:to:cc; bh=Y5TvyICc8d9t41nnsu7puTvMuWTSp2+6bN2hR6XdoD8=; b=FPrKKTFmIIrhXCK1a8bx0Gn0ZQdsswBQaJ6AcU4bdHhAv3FjPdWHeD6gFyulCFqoQf 8Ev6qu/iHol/CbvKBcjHgoIJRJzq3MUTFoZsXmwDMcsi+Qzb+ioohmiHkQMiO584Xqcm 3ufSvymy+GTp+Z/M7xxzl41Pr+8hzIqnNyWpVZwIQQnS8NGGru1KNkQquKQ9DH8ODztz nLkMaxwXBlaAiLiX+04wqiuxR8hikX1dzbdwP4lQQX314JMeqfcI9MDPPXug+QfyppfG a6grl/lOUGAxn6LNav8AW61Kc4S7JUpJqkDasX1rVL7l1cRykE+XrDWarl+uwQVvWPrv xvlw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:x-gm-message-state:from:to:cc; bh=Y5TvyICc8d9t41nnsu7puTvMuWTSp2+6bN2hR6XdoD8=; b=YWbNRkqjB2eV11LNX8QDr6orsjdeQsIVJdFzbYxCFKh5JXGaPF+AVVNbyH4324L1sT miY+K0y/RHWaqWFApW8lQBu6rh4xBCic3+65S9cz/01hNyFY8ZJWhrJbhaCe4Vo5PqzB czyhYN7y+Be4mb5Ez8H/XzBFxdgzZwwzYfmnmV+8GjplpRyOJGbt4oQ/ZVYxVYz++0Ov JxkY1f+DCFN+NRQT1sKSo5LM9tum949B260c/LYZBlfATtb1sjOdpqm7odVGqKUeTnVV eRKidzPc4R21Me7mDwGssQN7HY5w3hGdMBQL/eUFhcp2zaWFJ8Ww4SW1R5z1SojI0aAw 9SWw== X-Gm-Message-State: ACgBeo0CUjlEdj8rGfo9m12rIcfH/1yoAc67aMHRQpbpDn4N8cvnbsoP hpaoBFmr8OrMk/h9dz2AAsOtsxfUIp7ENyHyO9+1Gg== X-Google-Smtp-Source: AA6agR5d01Pm6wu3vbijZCaWwzO5G1sfm5AIHiHcJvlQ6r93IvYqNVc/zAhJ9di6/dSYm6ZI88xapY6TE2XXsAWQ/Ms= X-Received: by 2002:a0d:d40d:0:b0:322:d4c0:c6f6 with SMTP id w13-20020a0dd40d000000b00322d4c0c6f6mr23100302ywd.428.1659519894650; Wed, 03 Aug 2022 02:44:54 -0700 (PDT) MIME-Version: 1.0 References: <20220701142310.2188015-1-glider@google.com> <20220701142310.2188015-11-glider@google.com> In-Reply-To: From: Alexander Potapenko Date: Wed, 3 Aug 2022 11:44:18 +0200 Message-ID: Subject: Re: [PATCH v4 10/45] libnvdimm/pfn_dev: increase MAX_STRUCT_PAGE_SIZE To: Marco Elver , Dan Williams Cc: Alexander Viro , Alexei Starovoitov , Andrew Morton , Andrey Konovalov , Andy Lutomirski , Arnd Bergmann , Borislav Petkov , Christoph Hellwig , Christoph Lameter , David Rientjes , Dmitry Vyukov , Eric Dumazet , Greg Kroah-Hartman , Herbert Xu , Ilya Leoshkevich , Ingo Molnar , Jens Axboe , Joonsoo Kim , Kees Cook , Mark Rutland , Matthew Wilcox , "Michael S. Tsirkin" , Pekka Enberg , Peter Zijlstra , Petr Mladek , Steven Rostedt , Thomas Gleixner , Vasily Gorbik , Vegard Nossum , Vlastimil Babka , kasan-dev , Linux Memory Management List , Linux-Arch , LKML Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org (+ Dan Williams) (resending with patch context included) On Mon, Jul 11, 2022 at 6:27 PM Marco Elver wrote: > > On Fri, 1 Jul 2022 at 16:23, Alexander Potapenko wrot= e: > > > > KMSAN adds extra metadata fields to struct page, so it does not fit int= o > > 64 bytes anymore. > > Does this somehow cause extra space being used in all kernel configs? > If not, it would be good to note this in the commit message. > I actually couldn't verify this on QEMU, because the driver never got loade= d. Looks like this increases the amount of memory used by the nvdimm driver in all kernel configs that enable it (including those that don't use KMSAN), but I am not sure how much is that. Dan, do you know how bad increasing MAX_STRUCT_PAGE_SIZE can be? > > > Signed-off-by: Alexander Potapenko > > Reviewed-by: Marco Elver > > > --- > > Link: https://linux-review.googlesource.com/id/I353796acc6a850bfd7bb342= aa1b63e616fc614f1 > > --- > > drivers/nvdimm/nd.h | 2 +- > > drivers/nvdimm/pfn_devs.c | 2 +- > > 2 files changed, 2 insertions(+), 2 deletions(-) > > > > diff --git a/drivers/nvdimm/nd.h b/drivers/nvdimm/nd.h > > index ec5219680092d..85ca5b4da3cf3 100644 > > --- a/drivers/nvdimm/nd.h > > +++ b/drivers/nvdimm/nd.h > > @@ -652,7 +652,7 @@ void devm_namespace_disable(struct device *dev, > > struct nd_namespace_common *ndns); > > #if IS_ENABLED(CONFIG_ND_CLAIM) > > /* max struct page size independent of kernel config */ > > -#define MAX_STRUCT_PAGE_SIZE 64 > > +#define MAX_STRUCT_PAGE_SIZE 128 > > int nvdimm_setup_pfn(struct nd_pfn *nd_pfn, struct dev_pagemap *pgmap)= ; > > #else > > static inline int nvdimm_setup_pfn(struct nd_pfn *nd_pfn, > > diff --git a/drivers/nvdimm/pfn_devs.c b/drivers/nvdimm/pfn_devs.c > > index 0e92ab4b32833..61af072ac98f9 100644 > > --- a/drivers/nvdimm/pfn_devs.c > > +++ b/drivers/nvdimm/pfn_devs.c > > @@ -787,7 +787,7 @@ static int nd_pfn_init(struct nd_pfn *nd_pfn) > > * when populating the vmemmap. This *should* be equal = to > > * PMD_SIZE for most architectures. > > * > > - * Also make sure size of struct page is less than 64. = We > > + * Also make sure size of struct page is less than 128.= We > > * want to make sure we use large enough size here so t= hat > > * we don't have a dynamic reserve space depending on > > * struct page size. But we also want to make sure we n= otice > > -- > > 2.37.0.rc0.161.g10f37bed90-goog > > --=20 Alexander Potapenko Software Engineer Google Germany GmbH Erika-Mann-Stra=C3=9Fe, 33 80636 M=C3=BCnchen Gesch=C3=A4ftsf=C3=BChrer: Paul Manicle, Liana Sebastian Registergericht und -nummer: Hamburg, HRB 86891 Sitz der Gesellschaft: Hamburg