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 26AC1C468C6 for ; Thu, 19 Jul 2018 08:49:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DD42220693 for ; Thu, 19 Jul 2018 08:49:28 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org DD42220693 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 S1731465AbeGSJbJ (ORCPT ); Thu, 19 Jul 2018 05:31:09 -0400 Received: from mga04.intel.com ([192.55.52.120]:10712 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727470AbeGSJbJ (ORCPT ); Thu, 19 Jul 2018 05:31:09 -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 01:49:02 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.51,374,1526367600"; d="scan'208";a="76038305" Received: from yhuang6-ux31a.sh.intel.com ([10.239.195.246]) by orsmga002.jf.intel.com with ESMTP; 19 Jul 2018 01:49:00 -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 , Dan Williams , Dave Hansen , Daniel Jordan Subject: [PATCH v3 5/8] swap: Unify normal/huge code path in put_swap_page() Date: Thu, 19 Jul 2018 16:48:39 +0800 Message-Id: <20180719084842.11385-6-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, the normal/huge code path in put_swap_page() and several helper functions are unified to avoid duplicated code, bugs, etc. and make it easier to review the code. The removed lines are more than added lines. And the binary size is kept exactly same when CONFIG_TRANSPARENT_HUGEPAGE=n. Signed-off-by: "Huang, Ying" Suggested-by: Dave Hansen Reviewed-by: Daniel Jordan 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 | 83 ++++++++++++++++++++++++++--------------------------------- 1 file changed, 37 insertions(+), 46 deletions(-) diff --git a/mm/swapfile.c b/mm/swapfile.c index 96018207b582..407f97287ab3 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -205,8 +205,16 @@ static void discard_swap_cluster(struct swap_info_struct *si, #ifdef CONFIG_THP_SWAP #define SWAPFILE_CLUSTER HPAGE_PMD_NR + +#define swap_entry_size(size) (size) #else #define SWAPFILE_CLUSTER 256 + +/* + * Define swap_entry_size() as constant to let compiler to optimize + * out some code if !CONFIG_THP_SWAP + */ +#define swap_entry_size(size) 1 #endif #define LATENCY_LIMIT 256 @@ -1253,18 +1261,7 @@ void swap_free(swp_entry_t entry) /* * Called after dropping swapcache to decrease refcnt to swap entries. */ -static void swapcache_free(swp_entry_t entry) -{ - struct swap_info_struct *p; - - p = _swap_info_get(entry); - if (p) { - if (!__swap_entry_free(p, entry, SWAP_HAS_CACHE)) - free_swap_slot(entry); - } -} - -static void swapcache_free_cluster(swp_entry_t entry) +void put_swap_page(struct page *page, swp_entry_t entry) { unsigned long offset = swp_offset(entry); unsigned long idx = offset / SWAPFILE_CLUSTER; @@ -1273,39 +1270,41 @@ static void swapcache_free_cluster(swp_entry_t entry) unsigned char *map; unsigned int i, free_entries = 0; unsigned char val; - - if (!IS_ENABLED(CONFIG_THP_SWAP)) - return; + int size = swap_entry_size(hpage_nr_pages(page)); si = _swap_info_get(entry); if (!si) return; - ci = lock_cluster(si, offset); - VM_BUG_ON(!cluster_is_huge(ci)); - map = si->swap_map + offset; - for (i = 0; i < SWAPFILE_CLUSTER; i++) { - val = map[i]; - VM_BUG_ON(!(val & SWAP_HAS_CACHE)); - 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) { - spin_lock(&si->lock); + if (size == SWAPFILE_CLUSTER) { ci = lock_cluster(si, offset); - memset(map, 0, SWAPFILE_CLUSTER); + VM_BUG_ON(!cluster_is_huge(ci)); + map = si->swap_map + offset; + for (i = 0; i < SWAPFILE_CLUSTER; i++) { + val = map[i]; + VM_BUG_ON(!(val & SWAP_HAS_CACHE)); + 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); - mem_cgroup_uncharge_swap(entry, SWAPFILE_CLUSTER); - swap_free_cluster(si, idx); - spin_unlock(&si->lock); - } else if (free_entries) { - for (i = 0; i < SWAPFILE_CLUSTER; i++, entry.val++) { + if (free_entries == SWAPFILE_CLUSTER) { + spin_lock(&si->lock); + ci = lock_cluster(si, offset); + memset(map, 0, SWAPFILE_CLUSTER); + unlock_cluster(ci); + mem_cgroup_uncharge_swap(entry, SWAPFILE_CLUSTER); + swap_free_cluster(si, idx); + spin_unlock(&si->lock); + 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); } @@ -1329,14 +1328,6 @@ int split_swap_cluster(swp_entry_t entry) } #endif -void put_swap_page(struct page *page, swp_entry_t entry) -{ - if (!PageTransHuge(page)) - swapcache_free(entry); - else - swapcache_free_cluster(entry); -} - static int swp_entry_cmp(const void *ent1, const void *ent2) { const swp_entry_t *e1 = ent1, *e2 = ent2; -- 2.16.4