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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 73344C433F5 for ; Wed, 27 Oct 2021 05:52:20 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id F168C608FE for ; Wed, 27 Oct 2021 05:52:19 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org F168C608FE Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=suse.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvack.org Received: by kanga.kvack.org (Postfix) id 679D4940008; Wed, 27 Oct 2021 01:52:19 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 629F6940007; Wed, 27 Oct 2021 01:52:19 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 4F2E8940008; Wed, 27 Oct 2021 01:52:19 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0159.hostedemail.com [216.40.44.159]) by kanga.kvack.org (Postfix) with ESMTP id 3E8A7940007 for ; Wed, 27 Oct 2021 01:52:19 -0400 (EDT) Received: from smtpin26.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id D3CC532071 for ; Wed, 27 Oct 2021 05:52:18 +0000 (UTC) X-FDA: 78741147156.26.0A8C63A Received: from smtp-out2.suse.de (smtp-out2.suse.de [195.135.220.29]) by imf02.hostedemail.com (Postfix) with ESMTP id C667D7001712 for ; Wed, 27 Oct 2021 05:52:14 +0000 (UTC) Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out2.suse.de (Postfix) with ESMTPS id DEDA61FD4A; Wed, 27 Oct 2021 05:52:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1635313936; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=eYetLBlAcojUYZGAtj4Ll7PYw0ihUehplkOn+pQk5fc=; b=swdqjHjYrEFfj86WvsqxVcWvw+ioDZFBJ7EV0euU5G1mrIpIlxmfjTj4ht6sndtLQLptFU rkEu+ZmOXM5O7BNVDt//B8nj79qjSH5rf96Y2da0C7ZheP+88pyIQZ6VNTiRD80K9gwIxg 0AKo9uvODwqOK/Bg1nOle5quATMEfqs= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1635313936; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=eYetLBlAcojUYZGAtj4Ll7PYw0ihUehplkOn+pQk5fc=; b=RIl8BhaNn++LlFjZld6LWwAiEqkOWUR/wXzVAID0U8YP1x2WZ+n8mleOJhxi9+iw6/t8M2 J0ibryUAR6vb9zDg== Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id 728A513E6D; Wed, 27 Oct 2021 05:52:16 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id BycVGRDpeGEnTgAAMHmgww (envelope-from ); Wed, 27 Oct 2021 05:52:16 +0000 Date: Wed, 27 Oct 2021 07:52:14 +0200 From: Oscar Salvador To: Mike Kravetz Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Matthew Wilcox , Muchun Song , Andrew Morton , Pasha Tatashin Subject: Re: [PATCH] hugetlb: remove unnecessary set_page_count in prep_compound_gigantic_page Message-ID: References: <20211026220635.35187-1-mike.kravetz@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20211026220635.35187-1-mike.kravetz@oracle.com> X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: C667D7001712 X-Stat-Signature: tobj51wsbdo1411dzhu6nfhzjxftopj7 Authentication-Results: imf02.hostedemail.com; dkim=pass header.d=suse.de header.s=susede2_rsa header.b=swdqjHjY; dkim=pass header.d=suse.de header.s=susede2_ed25519 header.b=RIl8BhaN; spf=pass (imf02.hostedemail.com: domain of osalvador@suse.de designates 195.135.220.29 as permitted sender) smtp.mailfrom=osalvador@suse.de; dmarc=pass (policy=none) header.from=suse.de X-HE-Tag: 1635313934-825220 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 Tue, Oct 26, 2021 at 03:06:35PM -0700, Mike Kravetz wrote: > In commit 7118fc2906e29 ("hugetlb: address ref count racing in > prep_compound_gigantic_page"), page_ref_freeze is used to atomically > zero the ref count of tail pages iff they are 1. The unconditional > call to set_page_count(0) was left in the code. This call is after > page_ref_freeze so it is really a noop. > > Remove redundant and unnecessary set_page_count call. > > Fixes: 7118fc2906e29 ("hugetlb: address ref count racing in prep_compound_gigantic_page") > Suggested-by: Pasha Tatashin > Signed-off-by: Mike Kravetz Reviewed-by: Oscar Salvador > --- > mm/hugetlb.c | 1 - > 1 file changed, 1 deletion(-) > > diff --git a/mm/hugetlb.c b/mm/hugetlb.c > index 906fe8a3b93d..88047a367080 100644 > --- a/mm/hugetlb.c > +++ b/mm/hugetlb.c > @@ -1795,7 +1795,6 @@ static bool __prep_compound_gigantic_page(struct page *page, unsigned int order, > } else { > VM_BUG_ON_PAGE(page_count(p), p); > } > - set_page_count(p, 0); > set_compound_head(p, page); > } > atomic_set(compound_mapcount_ptr(page), -1); > -- > 2.31.1 > > -- Oscar Salvador SUSE Labs