From patchwork Fri Sep 6 14:53:34 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexander Duyck X-Patchwork-Id: 11135465 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 4F9F91395 for ; Fri, 6 Sep 2019 14:53:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 27F2A206A5 for ; Fri, 6 Sep 2019 14:53:42 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="F08BO7BS" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2405470AbfIFOxg (ORCPT ); Fri, 6 Sep 2019 10:53:36 -0400 Received: from mail-pg1-f195.google.com ([209.85.215.195]:40566 "EHLO mail-pg1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2394684AbfIFOxg (ORCPT ); Fri, 6 Sep 2019 10:53:36 -0400 Received: by mail-pg1-f195.google.com with SMTP id w10so3640350pgj.7; Fri, 06 Sep 2019 07:53:35 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:from:to:cc:date:message-id:in-reply-to:references :user-agent:mime-version:content-transfer-encoding; bh=yrM68/18qPKHZ9DUNXRIzqwwEnWiG4Tl6cc4C1fGcgo=; b=F08BO7BSrGrfQeuaby107wTUULESYHMJ7AOaEF+Hn8D5HHpHpYjfiOdTOXZsgN96mb zo3cIiADSm7/YUbXVc9ff5E1bg9AZLc6AoFPIq979AlGhTl4bohVyZhnCWM1r7OyEmxr pfYSTAppGSDLHI+eetE+RJIow7NJz9/Ud08mUQ9gIInnCxKwk26kzCo4geaCyX5g1BDK xCK3WPe0f7vo9mv8eOFY6tuZqetwYK++GD9OnB/3eQP0DzzCjqZwvI27ul+Ek3ZizGoa KyluUVUB7KGqWoqEUtKgdn6uonAibcK9ouPqdNAMP17fsIm1YXqbs0JBhQ8MD30VZx/o N0Wg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:from:to:cc:date:message-id:in-reply-to :references:user-agent:mime-version:content-transfer-encoding; bh=yrM68/18qPKHZ9DUNXRIzqwwEnWiG4Tl6cc4C1fGcgo=; b=PuCfvyOu9RM7UA8LiGdD9w4aEafVK36rJoS/7iBt0ZG7ogwtsy/h4UQKhOJth9JDyV slP4qqGLoJ1+qFhWBF4Ls3A+J7P8miizvGvuim1XnQRN4kDw20frBlRfNfn53CyR7DJZ +WaBGU9lZdmSsEPKSVZrMhBwicJJot9DG1lAr1TjfApSZGcP58lMgo54k+2nd2WV/b34 J/0HLe09fQCVsm9KIHmmfpiazSn0skVxLa0Py4R6D7H30Al8r3eqMKXMW0Z1CP4/TPfS /pmCbFtfgPtSBypSA4k4nQLhl01qik03XKU1VHtv2dMDaJU7J+iNFGwNT6GnqiMIHBCv /S1w== X-Gm-Message-State: APjAAAXPwvTj9S0/eheceqtzkX3Ca2BzRkOkLwgW/p60zQTeDwYnzOBP Z3kOgNPtKi072DmxKlA3ypYUeyQY X-Google-Smtp-Source: APXvYqyrQkzzi8Sbhj6vhLTR4dGTZW+Kk2AIeDlnJIKM3KMBnXdma+i7svr0tEnpvrl548l+Yy3/6Q== X-Received: by 2002:a62:e403:: with SMTP id r3mr10963491pfh.251.1567781615299; Fri, 06 Sep 2019 07:53:35 -0700 (PDT) Received: from localhost.localdomain ([2001:470:b:9c3:9e5c:8eff:fe4f:f2d0]) by smtp.gmail.com with ESMTPSA id 67sm5207877pjo.29.2019.09.06.07.53.34 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 06 Sep 2019 07:53:34 -0700 (PDT) Subject: [PATCH v8 2/7] mm: Adjust shuffle code to allow for future coalescing From: Alexander Duyck To: nitesh@redhat.com, kvm@vger.kernel.org, mst@redhat.com, david@redhat.com, dave.hansen@intel.com, linux-kernel@vger.kernel.org, willy@infradead.org, mhocko@kernel.org, linux-mm@kvack.org, akpm@linux-foundation.org, virtio-dev@lists.oasis-open.org, osalvador@suse.de Cc: yang.zhang.wz@gmail.com, pagupta@redhat.com, riel@surriel.com, konrad.wilk@oracle.com, lcapitulino@redhat.com, wei.w.wang@intel.com, aarcange@redhat.com, pbonzini@redhat.com, dan.j.williams@intel.com, alexander.h.duyck@linux.intel.com Date: Fri, 06 Sep 2019 07:53:34 -0700 Message-ID: <20190906145333.32552.95238.stgit@localhost.localdomain> In-Reply-To: <20190906145213.32552.30160.stgit@localhost.localdomain> References: <20190906145213.32552.30160.stgit@localhost.localdomain> User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org From: Alexander Duyck Move the head/tail adding logic out of the shuffle code and into the __free_one_page function since ultimately that is where it is really needed anyway. By doing this we should be able to reduce the overhead and can consolidate all of the list addition bits in one spot. Signed-off-by: Alexander Duyck Reviewed-by: Dan Williams --- include/linux/mmzone.h | 12 -------- mm/page_alloc.c | 70 +++++++++++++++++++++++++++--------------------- mm/shuffle.c | 9 +----- mm/shuffle.h | 12 ++++++++ 4 files changed, 53 insertions(+), 50 deletions(-) diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index bda20282746b..125f300981c6 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h @@ -116,18 +116,6 @@ static inline void add_to_free_area_tail(struct page *page, struct free_area *ar area->nr_free++; } -#ifdef CONFIG_SHUFFLE_PAGE_ALLOCATOR -/* Used to preserve page allocation order entropy */ -void add_to_free_area_random(struct page *page, struct free_area *area, - int migratetype); -#else -static inline void add_to_free_area_random(struct page *page, - struct free_area *area, int migratetype) -{ - add_to_free_area(page, area, migratetype); -} -#endif - /* Used for pages which are on another list */ static inline void move_to_free_area(struct page *page, struct free_area *area, int migratetype) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index c5d62f1c2851..4e4356ba66c7 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -878,6 +878,36 @@ static inline struct capture_control *task_capc(struct zone *zone) #endif /* CONFIG_COMPACTION */ /* + * If this is not the largest possible page, check if the buddy + * of the next-highest order is free. If it is, it's possible + * that pages are being freed that will coalesce soon. In case, + * that is happening, add the free page to the tail of the list + * so it's less likely to be used soon and more likely to be merged + * as a higher order page + */ +static inline bool +buddy_merge_likely(unsigned long pfn, unsigned long buddy_pfn, + struct page *page, unsigned int order) +{ + struct page *higher_page, *higher_buddy; + unsigned long combined_pfn; + + if (order >= MAX_ORDER - 2) + return false; + + if (!pfn_valid_within(buddy_pfn)) + return false; + + combined_pfn = buddy_pfn & pfn; + higher_page = page + (combined_pfn - pfn); + buddy_pfn = __find_buddy_pfn(combined_pfn, order + 1); + higher_buddy = higher_page + (buddy_pfn - combined_pfn); + + return pfn_valid_within(buddy_pfn) && + page_is_buddy(higher_page, higher_buddy, order + 1); +} + +/* * Freeing function for a buddy system allocator. * * The concept of a buddy system is to maintain direct-mapped table @@ -906,11 +936,12 @@ static inline void __free_one_page(struct page *page, struct zone *zone, unsigned int order, int migratetype) { - unsigned long combined_pfn; + struct capture_control *capc = task_capc(zone); unsigned long uninitialized_var(buddy_pfn); - struct page *buddy; + unsigned long combined_pfn; + struct free_area *area; unsigned int max_order; - struct capture_control *capc = task_capc(zone); + struct page *buddy; max_order = min_t(unsigned int, MAX_ORDER, pageblock_order + 1); @@ -979,35 +1010,12 @@ static inline void __free_one_page(struct page *page, done_merging: set_page_order(page, order); - /* - * If this is not the largest possible page, check if the buddy - * of the next-highest order is free. If it is, it's possible - * that pages are being freed that will coalesce soon. In case, - * that is happening, add the free page to the tail of the list - * so it's less likely to be used soon and more likely to be merged - * as a higher order page - */ - if ((order < MAX_ORDER-2) && pfn_valid_within(buddy_pfn) - && !is_shuffle_order(order)) { - struct page *higher_page, *higher_buddy; - combined_pfn = buddy_pfn & pfn; - higher_page = page + (combined_pfn - pfn); - buddy_pfn = __find_buddy_pfn(combined_pfn, order + 1); - higher_buddy = higher_page + (buddy_pfn - combined_pfn); - if (pfn_valid_within(buddy_pfn) && - page_is_buddy(higher_page, higher_buddy, order + 1)) { - add_to_free_area_tail(page, &zone->free_area[order], - migratetype); - return; - } - } - - if (is_shuffle_order(order)) - add_to_free_area_random(page, &zone->free_area[order], - migratetype); + area = &zone->free_area[order]; + if (is_shuffle_order(order) ? shuffle_pick_tail() : + buddy_merge_likely(pfn, buddy_pfn, page, order)) + add_to_free_area_tail(page, area, migratetype); else - add_to_free_area(page, &zone->free_area[order], migratetype); - + add_to_free_area(page, area, migratetype); } /* diff --git a/mm/shuffle.c b/mm/shuffle.c index 9ba542ecf335..345cb4347455 100644 --- a/mm/shuffle.c +++ b/mm/shuffle.c @@ -4,7 +4,6 @@ #include #include #include -#include #include #include "internal.h" #include "shuffle.h" @@ -190,8 +189,7 @@ struct batched_bit_entropy { static DEFINE_PER_CPU(struct batched_bit_entropy, batched_entropy_bool); -void add_to_free_area_random(struct page *page, struct free_area *area, - int migratetype) +bool __shuffle_pick_tail(void) { struct batched_bit_entropy *batch; unsigned long entropy; @@ -213,8 +211,5 @@ void add_to_free_area_random(struct page *page, struct free_area *area, batch->position = position; entropy = batch->entropy_bool; - if (1ul & (entropy >> position)) - add_to_free_area(page, area, migratetype); - else - add_to_free_area_tail(page, area, migratetype); + return 1ul & (entropy >> position); } diff --git a/mm/shuffle.h b/mm/shuffle.h index 777a257a0d2f..0723eb97f22f 100644 --- a/mm/shuffle.h +++ b/mm/shuffle.h @@ -3,6 +3,7 @@ #ifndef _MM_SHUFFLE_H #define _MM_SHUFFLE_H #include +#include /* * SHUFFLE_ENABLE is called from the command line enabling path, or by @@ -22,6 +23,7 @@ enum mm_shuffle_ctl { DECLARE_STATIC_KEY_FALSE(page_alloc_shuffle_key); extern void page_alloc_shuffle(enum mm_shuffle_ctl ctl); extern void __shuffle_free_memory(pg_data_t *pgdat); +extern bool __shuffle_pick_tail(void); static inline void shuffle_free_memory(pg_data_t *pgdat) { if (!static_branch_unlikely(&page_alloc_shuffle_key)) @@ -43,6 +45,11 @@ static inline bool is_shuffle_order(int order) return false; return order >= SHUFFLE_ORDER; } + +static inline bool shuffle_pick_tail(void) +{ + return __shuffle_pick_tail(); +} #else static inline void shuffle_free_memory(pg_data_t *pgdat) { @@ -60,5 +67,10 @@ static inline bool is_shuffle_order(int order) { return false; } + +static inline bool shuffle_pick_tail(void) +{ + return false; +} #endif #endif /* _MM_SHUFFLE_H */