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,URIBL_BLOCKED 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 0C4FAC433ED for ; Thu, 13 May 2021 16:51:12 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 7F0B5613C5 for ; Thu, 13 May 2021 16:51:11 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7F0B5613C5 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id BEFF06B0036; Thu, 13 May 2021 12:51:10 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id BA01E6B006E; Thu, 13 May 2021 12:51:10 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id A40926B0070; Thu, 13 May 2021 12:51:10 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0155.hostedemail.com [216.40.44.155]) by kanga.kvack.org (Postfix) with ESMTP id 75C446B0036 for ; Thu, 13 May 2021 12:51:10 -0400 (EDT) Received: from smtpin35.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 0ED1AA2DF for ; Thu, 13 May 2021 16:51:10 +0000 (UTC) X-FDA: 78136797900.35.CE605C7 Received: from mail-ej1-f46.google.com (mail-ej1-f46.google.com [209.85.218.46]) by imf01.hostedemail.com (Postfix) with ESMTP id 8043B5001531 for ; Thu, 13 May 2021 16:51:08 +0000 (UTC) Received: by mail-ej1-f46.google.com with SMTP id u21so40748031ejo.13 for ; Thu, 13 May 2021 09:51:09 -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:to :cc; bh=d+x/gpF6l0HoceprgaR+m+dBIab4JXxPwBNySb5f8CY=; b=kdPIZROcykp+3ZiaBH0uhIag+D1DVbvcU9m/td9lrDAczqXZpBOG5Hs7cAdSisxAdE uk4MgspLwNUEwKFAklFzc0EdjPEjcLUJGk2hw0mSAwxg+w6epSfnA8U6I3eRep5D+qWn duQ1M6VVn4SvIC5qr556hZrkGEhAaezP7GyUrxMe8gYriwyKywEm2Yvgt8IjJQqTJTPa BeM85Ij2irgx9pHQyLOMLz8z40A04ZOcWtug+fSq9oru/j6eYFqu76YBD9WPiaqHBMS1 VuJ/MjB5lT0zOke0wIpdSqVq07LvM3u2i3sGafCL/PVCZ/6SZ69N/mFroEPzwwqempas cHHQ== 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=d+x/gpF6l0HoceprgaR+m+dBIab4JXxPwBNySb5f8CY=; b=LoxXxmI+joU3yOh4Yxk6RxGVj6iBTgB8VgW7M9L3mEevCG93X5d1U+e7YxawOG0tHR LshKJCk+bBZLf1FCoKXX+qPh8DhofMUevE9cDquFu677wQ3s9TCD0AgfzvUbp0R5nVu5 RHOIaJ7KKc+ChZMw4XSlpM+TIxPOfIrXWdl9Stq+Hsd7CQmr78kqMkJtWC36zc0MGQ5r jvSmE70v8I8hrWByqDEaKdVqvDkTq36yH32664cLuE9ZKvCjIQidx4EabGQXZnJX+3ez 9cipyGF1vrnNN8uGkwodBXZT6TT2KSahvNAEFduSdARPT7ZRBmPHHpPyqXnln2HEYICj TukQ== X-Gm-Message-State: AOAM5339vZLAczICW3qgmKZIR2jjo2feW+KE4hutkfeg1cp3TmQ92dLo I8u9TJ0sks06DDrjlTc/cuumGHX67dgZPjXDjHc= X-Google-Smtp-Source: ABdhPJyFr0RFygozyGcTC/b9RkCKOMNOZWjjgUbBTTPNQdqjs0ul0Up6iQhjq31yiRfEYzPNpkGONjY/sEQCndNfYr0= X-Received: by 2002:a17:906:a51:: with SMTP id x17mr44621223ejf.25.1620924668070; Thu, 13 May 2021 09:51:08 -0700 (PDT) MIME-Version: 1.0 References: <1620890438-9127-1-git-send-email-anshuman.khandual@arm.com> In-Reply-To: <1620890438-9127-1-git-send-email-anshuman.khandual@arm.com> From: Yang Shi Date: Thu, 13 May 2021 09:50:55 -0700 Message-ID: Subject: Re: [RFC] mm/thp: Update mm's MM_ANONPAGES stat in set_huge_zero_page() To: Anshuman Khandual Cc: Linux MM , Andrew Morton , Zi Yan , Linux Kernel Mailing List Content-Type: text/plain; charset="UTF-8" Authentication-Results: imf01.hostedemail.com; dkim=pass header.d=gmail.com header.s=20161025 header.b=kdPIZROc; dmarc=pass (policy=none) header.from=gmail.com; spf=pass (imf01.hostedemail.com: domain of shy828301@gmail.com designates 209.85.218.46 as permitted sender) smtp.mailfrom=shy828301@gmail.com X-Stat-Signature: eacm41xkpfopjmrj9nwug8w9tqksztkh X-Rspamd-Queue-Id: 8043B5001531 X-Rspamd-Server: rspam02 X-HE-Tag: 1620924668-679827 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 Thu, May 13, 2021 at 12:20 AM Anshuman Khandual wrote: > > Although the zero huge page is being shared across various processes, each > mapping needs to update its mm's MM_ANONPAGES stat by HPAGE_PMD_NR in order > to be consistent. This just updates the stats in set_huge_zero_page() after > the mapping gets created. I don't get why MM_ANONPAGES needs to be inc'ed when huge zero page is installed. This may cause inconsistency between some counters, for example, MM_ANONPAGES may be much bigger than anon LRU. MM_ANONPAGES should not be inc'ed unless a new page is allocated and installed, right? > > Cc: Andrew Morton > Cc: Zi Yan > Cc: linux-mm@kvack.org > Cc: linux-kernel@vger.kernel.org > Signed-off-by: Anshuman Khandual > --- > Should it update MM_SHMEM_PAGES instead ? Applies on latest mainline. > > mm/huge_memory.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/mm/huge_memory.c b/mm/huge_memory.c > index 63ed6b25deaa..262703304807 100644 > --- a/mm/huge_memory.c > +++ b/mm/huge_memory.c > @@ -706,6 +706,7 @@ static void set_huge_zero_page(pgtable_t pgtable, struct mm_struct *mm, > if (pgtable) > pgtable_trans_huge_deposit(mm, pmd, pgtable); > set_pmd_at(mm, haddr, pmd, entry); > + add_mm_counter(mm, MM_ANONPAGES, HPAGE_PMD_NR); > mm_inc_nr_ptes(mm); > } > > -- > 2.20.1 > >