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=-2.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 6E84AECDFAA for ; Fri, 13 Jul 2018 02:13:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 24996214AB for ; Fri, 13 Jul 2018 02:13:22 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 24996214AB Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388048AbeGMCZB (ORCPT ); Thu, 12 Jul 2018 22:25:01 -0400 Received: from mga18.intel.com ([134.134.136.126]:26096 "EHLO mga18.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387972AbeGMCZB (ORCPT ); Thu, 12 Jul 2018 22:25:01 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga007.fm.intel.com ([10.253.24.52]) by orsmga106.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 12 Jul 2018 19:12:40 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.51,346,1526367600"; d="scan'208";a="54012108" Received: from yongjuns-mobl2.ccr.corp.intel.com (HELO yhuang6-ux31a.ccr.corp.intel.com) ([10.254.213.67]) by fmsmga007.fm.intel.com with ESMTP; 12 Jul 2018 19:12:37 -0700 From: "Huang, Ying" To: Andrew Morton Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Huang Ying , Michal Hocko , Johannes Weiner , Shaohua Li , Hugh Dickins , Minchan Kim , Rik van Riel , Dave Hansen , Zi Yan , Daniel Jordan , Dan Williams , Naoya Horiguchi Subject: [PATCH] mm, swap: Make CONFIG_THP_SWAP depends on CONFIG_SWAP Date: Fri, 13 Jul 2018 10:12:28 +0800 Message-Id: <20180713021228.439-1-ying.huang@intel.com> X-Mailer: git-send-email 2.16.4 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Huang Ying CONFIG_THP_SWAP should depend on CONFIG_SWAP, because it's unreasonable to optimize swapping for THP (Transparent Huge Page) without basic swapping support. In original code, when CONFIG_SWAP=n and CONFIG_THP_SWAP=y, split_swap_cluster() will not be built because it is in swapfile.c, but it will be called in huge_memory.c. This doesn't trigger a build error in practice because the call site is enclosed by PageSwapCache(), which is defined to be constant 0 when CONFIG_SWAP=n. But this is fragile and should be fixed. The comments are fixed too to reflect the latest progress. Fixes: 38d8b4e6bdc8 ("mm, THP, swap: delay splitting THP during swap out") Signed-off-by: "Huang, Ying" Reviewed-by: Dan Williams Reviewed-by: Naoya Horiguchi Cc: Michal Hocko Cc: Johannes Weiner Cc: Shaohua Li Cc: Hugh Dickins Cc: Minchan Kim Cc: Rik van Riel Cc: Dave Hansen Cc: Zi Yan Cc: Daniel Jordan --- mm/Kconfig | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/mm/Kconfig b/mm/Kconfig index b78e7cd4e9fe..97114c94239c 100644 --- a/mm/Kconfig +++ b/mm/Kconfig @@ -419,10 +419,11 @@ config ARCH_WANTS_THP_SWAP config THP_SWAP def_bool y - depends on TRANSPARENT_HUGEPAGE && ARCH_WANTS_THP_SWAP + depends on TRANSPARENT_HUGEPAGE && ARCH_WANTS_THP_SWAP && SWAP help Swap transparent huge pages in one piece, without splitting. - XXX: For now this only does clustered swap space allocation. + XXX: For now, swap cluster backing transparent huge page + will be split after swapout. For selection by architectures with reasonable THP sizes. -- 2.16.4