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 2F338ECDE5F for ; Thu, 19 Jul 2018 08:49:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EB5F120693 for ; Thu, 19 Jul 2018 08:49:12 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org EB5F120693 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 S1731610AbeGSJbQ (ORCPT ); Thu, 19 Jul 2018 05:31:16 -0400 Received: from mga04.intel.com ([192.55.52.120]:10716 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727849AbeGSJbP (ORCPT ); Thu, 19 Jul 2018 05:31:15 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga002.jf.intel.com ([10.7.209.21]) by fmsmga104.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 19 Jul 2018 01:49:09 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.51,374,1526367600"; d="scan'208";a="76038339" Received: from yhuang6-ux31a.sh.intel.com ([10.239.195.246]) by orsmga002.jf.intel.com with ESMTP; 19 Jul 2018 01:49:07 -0700 From: Huang Ying To: Andrew Morton Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Huang Ying , Dave Hansen , Michal Hocko , Johannes Weiner , Shaohua Li , Hugh Dickins , Minchan Kim , Rik van Riel , Dan Williams , Daniel Jordan Subject: [PATCH v3 8/8] swap, put_swap_page: Share more between huge/normal code path Date: Thu, 19 Jul 2018 16:48:42 +0800 Message-Id: <20180719084842.11385-9-ying.huang@intel.com> X-Mailer: git-send-email 2.16.4 In-Reply-To: <20180719084842.11385-1-ying.huang@intel.com> References: <20180719084842.11385-1-ying.huang@intel.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org In this patch, locking related code is shared between huge/normal code path in put_swap_page() to reduce code duplication. And `free_entries == 0` case is merged into more general `free_entries != SWAPFILE_CLUSTER` case, because the new locking method makes it easy. The added lines is same as the removed lines. But the code size is increased when CONFIG_TRANSPARENT_HUGEPAGE=n. text data bss dec hex filename base: 24123 2004 340 26467 6763 mm/swapfile.o unified: 24485 2004 340 26829 68cd mm/swapfile.o Dig on step deeper with `size -A mm/swapfile.o` for base and unified kernel and compare the result, yields, -.text 17723 0 +.text 17835 0 -.orc_unwind_ip 1380 0 +.orc_unwind_ip 1480 0 -.orc_unwind 2070 0 +.orc_unwind 2220 0 -Total 26686 +Total 27048 The total difference is the same. The text segment difference is much smaller: 112. More difference comes from the ORC unwinder segments: (1480 + 2220) - (1380 + 2070) = 250. If the frame pointer unwinder is used, this costs nothing. Signed-off-by: "Huang, Ying" Reviewed-by: Daniel Jordan Cc: Dave Hansen Cc: Michal Hocko Cc: Johannes Weiner Cc: Shaohua Li Cc: Hugh Dickins Cc: Minchan Kim Cc: Rik van Riel Cc: Dan Williams --- mm/swapfile.c | 20 ++++++++++---------- 1 file changed, 10 insertions(+), 10 deletions(-) diff --git a/mm/swapfile.c b/mm/swapfile.c index d313f7512d26..2fe2e93cee0e 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -1284,8 +1284,8 @@ void put_swap_page(struct page *page, swp_entry_t entry) if (!si) return; + ci = lock_cluster_or_swap_info(si, offset); if (size == SWAPFILE_CLUSTER) { - ci = lock_cluster(si, offset); VM_BUG_ON(!cluster_is_huge(ci)); map = si->swap_map + offset; for (i = 0; i < SWAPFILE_CLUSTER; i++) { @@ -1294,13 +1294,9 @@ void put_swap_page(struct page *page, swp_entry_t entry) if (val == SWAP_HAS_CACHE) free_entries++; } - if (!free_entries) { - for (i = 0; i < SWAPFILE_CLUSTER; i++) - map[i] &= ~SWAP_HAS_CACHE; - } cluster_clear_huge(ci); - unlock_cluster(ci); if (free_entries == SWAPFILE_CLUSTER) { + unlock_cluster_or_swap_info(si, ci); spin_lock(&si->lock); ci = lock_cluster(si, offset); memset(map, 0, SWAPFILE_CLUSTER); @@ -1311,12 +1307,16 @@ void put_swap_page(struct page *page, swp_entry_t entry) return; } } - if (size == 1 || free_entries) { - for (i = 0; i < size; i++, entry.val++) { - if (!__swap_entry_free(si, entry, SWAP_HAS_CACHE)) - free_swap_slot(entry); + for (i = 0; i < size; i++, entry.val++) { + if (!__swap_entry_free_locked(si, offset + i, SWAP_HAS_CACHE)) { + unlock_cluster_or_swap_info(si, ci); + free_swap_slot(entry); + if (i == size - 1) + return; + lock_cluster_or_swap_info(si, offset); } } + unlock_cluster_or_swap_info(si, ci); } #ifdef CONFIG_THP_SWAP -- 2.16.4