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=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 B02BDC433E0 for ; Fri, 26 Feb 2021 01:18:06 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 46EEE64F27 for ; Fri, 26 Feb 2021 01:18:06 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 46EEE64F27 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id CB44E6B0072; Thu, 25 Feb 2021 20:18:05 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id C63A48D0009; Thu, 25 Feb 2021 20:18:05 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id B78988D0003; Thu, 25 Feb 2021 20:18:05 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0117.hostedemail.com [216.40.44.117]) by kanga.kvack.org (Postfix) with ESMTP id 988B86B0072 for ; Thu, 25 Feb 2021 20:18:05 -0500 (EST) Received: from smtpin20.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 640E4824C453 for ; Fri, 26 Feb 2021 01:18:05 +0000 (UTC) X-FDA: 77858657730.20.6E3EB11 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf21.hostedemail.com (Postfix) with ESMTP id 7479AE0011E3 for ; Fri, 26 Feb 2021 01:18:01 +0000 (UTC) Received: by mail.kernel.org (Postfix) with ESMTPSA id D187564F14; Fri, 26 Feb 2021 01:18:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1614302284; bh=Rgwf2N9AUfX4uo2Q6UMa+x09WD3wbzSI+HO4p0Dwso8=; h=Date:From:To:Subject:In-Reply-To:From; b=o0K0By2alDG/5kH8YByCxE65Zt7R8pQtR8R5DivmwhSfAN68sy5BKlXSj/V/CzoCA TWXslAe3TigZtvE/BUwpxhUdZ0EJcREf87fwWWet/zhfVdV9kKeutWtAyuRdHpzaXY uL7zOd2hMuAvMp5foVF2Fu7rJi035GjpRngkTZS4= Date: Thu, 25 Feb 2021 17:18:03 -0800 From: Andrew Morton To: akpm@linux-foundation.org, linmiaohe@huawei.com, linux-mm@kvack.org, mm-commits@vger.kernel.org, torvalds@linux-foundation.org Subject: [patch 043/118] mm/rmap: use page_not_mapped in try_to_unmap() Message-ID: <20210226011803.oZt-qQ9hD%akpm@linux-foundation.org> In-Reply-To: <20210225171452.713967e96554bb6a53e44a19@linux-foundation.org> User-Agent: s-nail v14.8.16 X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: 7479AE0011E3 X-Stat-Signature: ydhf4ka53b51phmu3th5hwmf14zrtjfj Received-SPF: none (linux-foundation.org>: No applicable sender policy available) receiver=imf21; identity=mailfrom; envelope-from=""; helo=mail.kernel.org; client-ip=198.145.29.99 X-HE-DKIM-Result: pass/pass X-HE-Tag: 1614302281-46832 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: From: Miaohe Lin Subject: mm/rmap: use page_not_mapped in try_to_unmap() page_mapcount_is_zero() calculates accurately how many mappings a hugepage has in order to check against 0 only. This is a waste of cpu time. We can do this via page_not_mapped() to save some possible atomic_read cycles. Remove the function page_mapcount_is_zero() as it's not used anymore and move page_not_mapped() above try_to_unmap() to avoid identifier undeclared compilation error. Link: https://lkml.kernel.org/r/20210130084904.35307-1-linmiaohe@huawei.com Signed-off-by: Miaohe Lin Signed-off-by: Andrew Morton --- mm/rmap.c | 11 +++-------- 1 file changed, 3 insertions(+), 8 deletions(-) --- a/mm/rmap.c~mm-rmap-use-page_not_mapped-in-try_to_unmap +++ a/mm/rmap.c @@ -1736,9 +1736,9 @@ static bool invalid_migration_vma(struct return vma_is_temporary_stack(vma); } -static int page_mapcount_is_zero(struct page *page) +static int page_not_mapped(struct page *page) { - return !total_mapcount(page); + return !page_mapped(page); } /** @@ -1756,7 +1756,7 @@ bool try_to_unmap(struct page *page, enu struct rmap_walk_control rwc = { .rmap_one = try_to_unmap_one, .arg = (void *)flags, - .done = page_mapcount_is_zero, + .done = page_not_mapped, .anon_lock = page_lock_anon_vma_read, }; @@ -1780,11 +1780,6 @@ bool try_to_unmap(struct page *page, enu return !page_mapcount(page) ? true : false; } -static int page_not_mapped(struct page *page) -{ - return !page_mapped(page); -} - /** * try_to_munlock - try to munlock a page * @page: the page to be munlocked _