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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8B3D7C4345F for ; Mon, 22 Apr 2024 10:52:43 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id F0DF56B009A; Mon, 22 Apr 2024 06:52:42 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id E95E46B009D; Mon, 22 Apr 2024 06:52:42 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id D368C6B009E; Mon, 22 Apr 2024 06:52:42 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0014.hostedemail.com [216.40.44.14]) by kanga.kvack.org (Postfix) with ESMTP id B15796B009A for ; Mon, 22 Apr 2024 06:52:42 -0400 (EDT) Received: from smtpin21.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay07.hostedemail.com (Postfix) with ESMTP id 5B7D9160B91 for ; Mon, 22 Apr 2024 10:52:42 +0000 (UTC) X-FDA: 82036854564.21.3B5AB2B Received: from out-178.mta0.migadu.com (out-178.mta0.migadu.com [91.218.175.178]) by imf02.hostedemail.com (Postfix) with ESMTP id BD9C080002 for ; Mon, 22 Apr 2024 10:52:40 +0000 (UTC) Authentication-Results: imf02.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=SofLs8EC; spf=pass (imf02.hostedemail.com: domain of yajun.deng@linux.dev designates 91.218.175.178 as permitted sender) smtp.mailfrom=yajun.deng@linux.dev; dmarc=pass (policy=none) header.from=linux.dev ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1713783161; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-transfer-encoding:content-transfer-encoding: in-reply-to:references:dkim-signature; bh=ESBueFFCicxxXb4Z+7ylQzVlc77asvp92RLfamr44V8=; b=lMq+N6uBhtx+wW+3w3XnQkzPE/oYTlPALoKHPyc7pZSkJcFewc9t+JhFiO5l002QmQrEv8 Vev2amy8Eq+l7AFSPcgT1T9GN974JvnYLBhWA65GJZx/28LhnUckgjArYMyu8WTOoBbdE/ JSoXCnvbRP2rQdccA5mKl9Az0rrbDEw= ARC-Authentication-Results: i=1; imf02.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=SofLs8EC; spf=pass (imf02.hostedemail.com: domain of yajun.deng@linux.dev designates 91.218.175.178 as permitted sender) smtp.mailfrom=yajun.deng@linux.dev; dmarc=pass (policy=none) header.from=linux.dev ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1713783161; a=rsa-sha256; cv=none; b=GZWN+spXB9/k7s9m7Sjr8QxDTejkirBp0+sg05A262+8aMq/fJpw8cQZLPNr9lLpzkGEZY dlFHeia9uyIqoXeInUEDqKj3Ouz+okajx4/b8EZKHbjT8RsWU0ieLORVW4N2wK1bppvtDy HDJ/nlt4G+fu0WWkOalnoGhXETeHmc0= X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1713783158; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=ESBueFFCicxxXb4Z+7ylQzVlc77asvp92RLfamr44V8=; b=SofLs8ECkVtz6Kcgh+S7ngLkJQLF/4Alo5ZBK/DZIM81VMdvqANwmxIw/JoYXVmLtD83AP j5tYXmAHSmQJypffgp1qUUJsoIyfR36wT6RiMmlmrrJn3vUUco6U/xH+p4b0XJ9woV4lkQ dkQ5Bjj+5/a9lsXcnA8cqJykoc0+zEU= From: Yajun Deng To: akpm@linux-foundation.org Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Yajun Deng Subject: [PATCH] mm/rmap: remove unnecessary page_table_lock Date: Mon, 22 Apr 2024 18:52:12 +0800 Message-Id: <20240422105212.1485788-1-yajun.deng@linux.dev> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT X-Rspamd-Queue-Id: BD9C080002 X-Stat-Signature: yqos8rex1opao9asnwibkaiu6fwioxfq X-Rspam-User: X-Rspamd-Server: rspam07 X-HE-Tag: 1713783160-888657 X-HE-Meta: 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 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000949, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: page_table_lock is a lock that for page table, we won't change page table in __anon_vma_prepare(). As we can see, it works well in anon_vma_clone(). They do the same operation. Remove unnecessary page_table_lock in __anon_vma_prepare(). Signed-off-by: Yajun Deng --- mm/rmap.c | 4 ---- 1 file changed, 4 deletions(-) diff --git a/mm/rmap.c b/mm/rmap.c index 2608c40dffad..e894640a9327 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -187,7 +187,6 @@ static void anon_vma_chain_link(struct vm_area_struct *vma, */ int __anon_vma_prepare(struct vm_area_struct *vma) { - struct mm_struct *mm = vma->vm_mm; struct anon_vma *anon_vma, *allocated; struct anon_vma_chain *avc; @@ -208,8 +207,6 @@ int __anon_vma_prepare(struct vm_area_struct *vma) } anon_vma_lock_write(anon_vma); - /* page_table_lock to protect against threads */ - spin_lock(&mm->page_table_lock); if (likely(!vma->anon_vma)) { vma->anon_vma = anon_vma; anon_vma_chain_link(vma, avc, anon_vma); @@ -217,7 +214,6 @@ int __anon_vma_prepare(struct vm_area_struct *vma) allocated = NULL; avc = NULL; } - spin_unlock(&mm->page_table_lock); anon_vma_unlock_write(anon_vma); if (unlikely(allocated)) -- 2.25.1