From patchwork Thu Mar 25 11:42:20 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mel Gorman X-Patchwork-Id: 12163801 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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,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 3E8F8C433DB for ; Thu, 25 Mar 2021 11:44:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0A86E6191D for ; Thu, 25 Mar 2021 11:44:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230166AbhCYLne (ORCPT ); Thu, 25 Mar 2021 07:43:34 -0400 Received: from outbound-smtp44.blacknight.com ([46.22.136.52]:56993 "EHLO outbound-smtp44.blacknight.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232290AbhCYLmv (ORCPT ); Thu, 25 Mar 2021 07:42:51 -0400 Received: from mail.blacknight.com (pemlinmail01.blacknight.ie [81.17.254.10]) by outbound-smtp44.blacknight.com (Postfix) with ESMTPS id CF6CCF8056 for ; Thu, 25 Mar 2021 11:42:49 +0000 (GMT) Received: (qmail 15475 invoked from network); 25 Mar 2021 11:42:49 -0000 Received: from unknown (HELO stampy.112glenside.lan) (mgorman@techsingularity.net@[84.203.22.4]) by 81.17.254.9 with ESMTPA; 25 Mar 2021 11:42:49 -0000 From: Mel Gorman To: Andrew Morton Cc: Chuck Lever , Jesper Dangaard Brouer , Christoph Hellwig , Alexander Duyck , Vlastimil Babka , Matthew Wilcox , Ilias Apalodimas , LKML , Linux-Net , Linux-MM , Linux-NFS , Mel Gorman Subject: [PATCH 1/9] mm/page_alloc: Rename alloced to allocated Date: Thu, 25 Mar 2021 11:42:20 +0000 Message-Id: <20210325114228.27719-2-mgorman@techsingularity.net> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20210325114228.27719-1-mgorman@techsingularity.net> References: <20210325114228.27719-1-mgorman@techsingularity.net> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org Review feedback of the bulk allocator twice found problems with "alloced" being a counter for pages allocated. The naming was based on the API name "alloc" and was based on the idea that verbal communication about malloc tends to use the fake word "malloced" instead of the fake word mallocated. To be consistent, this preparation patch renames alloced to allocated in rmqueue_bulk so the bulk allocator and per-cpu allocator use similar names when the bulk allocator is introduced. Signed-off-by: Mel Gorman Reviewed-by: Matthew Wilcox (Oracle) Acked-by: Vlastimil Babka --- mm/page_alloc.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index dfa9af064f74..8a3e13277e22 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -2908,7 +2908,7 @@ static int rmqueue_bulk(struct zone *zone, unsigned int order, unsigned long count, struct list_head *list, int migratetype, unsigned int alloc_flags) { - int i, alloced = 0; + int i, allocated = 0; spin_lock(&zone->lock); for (i = 0; i < count; ++i) { @@ -2931,7 +2931,7 @@ static int rmqueue_bulk(struct zone *zone, unsigned int order, * pages are ordered properly. */ list_add_tail(&page->lru, list); - alloced++; + allocated++; if (is_migrate_cma(get_pcppage_migratetype(page))) __mod_zone_page_state(zone, NR_FREE_CMA_PAGES, -(1 << order)); @@ -2940,12 +2940,12 @@ static int rmqueue_bulk(struct zone *zone, unsigned int order, /* * i pages were removed from the buddy list even if some leak due * to check_pcp_refill failing so adjust NR_FREE_PAGES based - * on i. Do not confuse with 'alloced' which is the number of + * on i. Do not confuse with 'allocated' which is the number of * pages added to the pcp list. */ __mod_zone_page_state(zone, NR_FREE_PAGES, -(i << order)); spin_unlock(&zone->lock); - return alloced; + return allocated; } #ifdef CONFIG_NUMA From patchwork Thu Mar 25 11:42:21 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mel Gorman X-Patchwork-Id: 12163807 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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,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 4ED5DC433C1 for ; Thu, 25 Mar 2021 11:44:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2C1EA619FF for ; Thu, 25 Mar 2021 11:44:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230341AbhCYLng (ORCPT ); Thu, 25 Mar 2021 07:43:36 -0400 Received: from outbound-smtp32.blacknight.com ([81.17.249.64]:43423 "EHLO outbound-smtp32.blacknight.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230284AbhCYLnB (ORCPT ); Thu, 25 Mar 2021 07:43:01 -0400 Received: from mail.blacknight.com (pemlinmail01.blacknight.ie [81.17.254.10]) by outbound-smtp32.blacknight.com (Postfix) with ESMTPS id 1584FBEB83 for ; Thu, 25 Mar 2021 11:43:00 +0000 (GMT) Received: (qmail 15945 invoked from network); 25 Mar 2021 11:42:59 -0000 Received: from unknown (HELO stampy.112glenside.lan) (mgorman@techsingularity.net@[84.203.22.4]) by 81.17.254.9 with ESMTPA; 25 Mar 2021 11:42:59 -0000 From: Mel Gorman To: Andrew Morton Cc: Chuck Lever , Jesper Dangaard Brouer , Christoph Hellwig , Alexander Duyck , Vlastimil Babka , Matthew Wilcox , Ilias Apalodimas , LKML , Linux-Net , Linux-MM , Linux-NFS , Mel Gorman Subject: [PATCH 2/9] mm/page_alloc: Add a bulk page allocator Date: Thu, 25 Mar 2021 11:42:21 +0000 Message-Id: <20210325114228.27719-3-mgorman@techsingularity.net> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20210325114228.27719-1-mgorman@techsingularity.net> References: <20210325114228.27719-1-mgorman@techsingularity.net> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org This patch adds a new page allocator interface via alloc_pages_bulk, and __alloc_pages_bulk_nodemask. A caller requests a number of pages to be allocated and added to a list. The API is not guaranteed to return the requested number of pages and may fail if the preferred allocation zone has limited free memory, the cpuset changes during the allocation or page debugging decides to fail an allocation. It's up to the caller to request more pages in batch if necessary. Note that this implementation is not very efficient and could be improved but it would require refactoring. The intent is to make it available early to determine what semantics are required by different callers. Once the full semantics are nailed down, it can be refactored. Signed-off-by: Mel Gorman Acked-by: Vlastimil Babka Signed-off-by: Mel Gorman --- include/linux/gfp.h | 11 +++++ mm/page_alloc.c | 118 ++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 129 insertions(+) diff --git a/include/linux/gfp.h b/include/linux/gfp.h index 0a88f84b08f4..4a304fd39916 100644 --- a/include/linux/gfp.h +++ b/include/linux/gfp.h @@ -518,6 +518,17 @@ static inline int arch_make_page_accessible(struct page *page) struct page *__alloc_pages(gfp_t gfp, unsigned int order, int preferred_nid, nodemask_t *nodemask); +int __alloc_pages_bulk(gfp_t gfp, int preferred_nid, + nodemask_t *nodemask, int nr_pages, + struct list_head *list); + +/* Bulk allocate order-0 pages */ +static inline unsigned long +alloc_pages_bulk(gfp_t gfp, unsigned long nr_pages, struct list_head *list) +{ + return __alloc_pages_bulk(gfp, numa_mem_id(), NULL, nr_pages, list); +} + /* * Allocate pages, preferring the node given as nid. The node must be valid and * online. For more general interface, see alloc_pages_node(). diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 8a3e13277e22..eb547470a7e4 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -4965,6 +4965,124 @@ static inline bool prepare_alloc_pages(gfp_t gfp_mask, unsigned int order, return true; } +/* + * __alloc_pages_bulk - Allocate a number of order-0 pages to a list + * @gfp: GFP flags for the allocation + * @preferred_nid: The preferred NUMA node ID to allocate from + * @nodemask: Set of nodes to allocate from, may be NULL + * @nr_pages: The number of pages desired on the list + * @page_list: List to store the allocated pages + * + * This is a batched version of the page allocator that attempts to + * allocate nr_pages quickly and add them to a list. + * + * Returns the number of pages on the list. + */ +int __alloc_pages_bulk(gfp_t gfp, int preferred_nid, + nodemask_t *nodemask, int nr_pages, + struct list_head *page_list) +{ + struct page *page; + unsigned long flags; + struct zone *zone; + struct zoneref *z; + struct per_cpu_pages *pcp; + struct list_head *pcp_list; + struct alloc_context ac; + gfp_t alloc_gfp; + unsigned int alloc_flags; + int allocated = 0; + + if (WARN_ON_ONCE(nr_pages <= 0)) + return 0; + + /* Use the single page allocator for one page. */ + if (nr_pages == 1) + goto failed; + + /* May set ALLOC_NOFRAGMENT, fragmentation will return 1 page. */ + gfp &= gfp_allowed_mask; + alloc_gfp = gfp; + if (!prepare_alloc_pages(gfp, 0, preferred_nid, nodemask, &ac, &alloc_gfp, &alloc_flags)) + return 0; + gfp = alloc_gfp; + + /* Find an allowed local zone that meets the high watermark. */ + for_each_zone_zonelist_nodemask(zone, z, ac.zonelist, ac.highest_zoneidx, ac.nodemask) { + unsigned long mark; + + if (cpusets_enabled() && (alloc_flags & ALLOC_CPUSET) && + !__cpuset_zone_allowed(zone, gfp)) { + continue; + } + + if (nr_online_nodes > 1 && zone != ac.preferred_zoneref->zone && + zone_to_nid(zone) != zone_to_nid(ac.preferred_zoneref->zone)) { + goto failed; + } + + mark = wmark_pages(zone, alloc_flags & ALLOC_WMARK_MASK) + nr_pages; + if (zone_watermark_fast(zone, 0, mark, + zonelist_zone_idx(ac.preferred_zoneref), + alloc_flags, gfp)) { + break; + } + } + + /* + * If there are no allowed local zones that meets the watermarks then + * try to allocate a single page and reclaim if necessary. + */ + if (!zone) + goto failed; + + /* Attempt the batch allocation */ + local_irq_save(flags); + pcp = &this_cpu_ptr(zone->pageset)->pcp; + pcp_list = &pcp->lists[ac.migratetype]; + + while (allocated < nr_pages) { + page = __rmqueue_pcplist(zone, ac.migratetype, alloc_flags, + pcp, pcp_list); + if (!page) { + /* Try and get at least one page */ + if (!allocated) + goto failed_irq; + break; + } + + /* + * Ideally this would be batched but the best way to do + * that cheaply is to first convert zone_statistics to + * be inaccurate per-cpu counter like vm_events to avoid + * a RMW cycle then do the accounting with IRQs enabled. + */ + __count_zid_vm_events(PGALLOC, zone_idx(zone), 1); + zone_statistics(ac.preferred_zoneref->zone, zone); + + prep_new_page(page, 0, gfp, 0); + list_add(&page->lru, page_list); + allocated++; + } + + local_irq_restore(flags); + + return allocated; + +failed_irq: + local_irq_restore(flags); + +failed: + page = __alloc_pages(gfp, 0, preferred_nid, nodemask); + if (page) { + list_add(&page->lru, page_list); + allocated = 1; + } + + return allocated; +} +EXPORT_SYMBOL_GPL(__alloc_pages_bulk); + /* * This is the 'heart' of the zoned buddy allocator. */ From patchwork Thu Mar 25 11:42:22 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mel Gorman X-Patchwork-Id: 12163805 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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,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 67B4CC433E1 for ; Thu, 25 Mar 2021 11:44:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 44DAA61A31 for ; Thu, 25 Mar 2021 11:44:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230284AbhCYLni (ORCPT ); Thu, 25 Mar 2021 07:43:38 -0400 Received: from outbound-smtp22.blacknight.com ([81.17.249.190]:58361 "EHLO outbound-smtp22.blacknight.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230478AbhCYLnL (ORCPT ); Thu, 25 Mar 2021 07:43:11 -0400 Received: from mail.blacknight.com (pemlinmail01.blacknight.ie [81.17.254.10]) by outbound-smtp22.blacknight.com (Postfix) with ESMTPS id 57A18BAA2C for ; Thu, 25 Mar 2021 11:43:10 +0000 (GMT) Received: (qmail 16560 invoked from network); 25 Mar 2021 11:43:10 -0000 Received: from unknown (HELO stampy.112glenside.lan) (mgorman@techsingularity.net@[84.203.22.4]) by 81.17.254.9 with ESMTPA; 25 Mar 2021 11:43:10 -0000 From: Mel Gorman To: Andrew Morton Cc: Chuck Lever , Jesper Dangaard Brouer , Christoph Hellwig , Alexander Duyck , Vlastimil Babka , Matthew Wilcox , Ilias Apalodimas , LKML , Linux-Net , Linux-MM , Linux-NFS , Mel Gorman Subject: [PATCH 3/9] mm/page_alloc: Add an array-based interface to the bulk page allocator Date: Thu, 25 Mar 2021 11:42:22 +0000 Message-Id: <20210325114228.27719-4-mgorman@techsingularity.net> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20210325114228.27719-1-mgorman@techsingularity.net> References: <20210325114228.27719-1-mgorman@techsingularity.net> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org The proposed callers for the bulk allocator store pages from the bulk allocator in an array. This patch adds an array-based interface to the API to avoid multiple list iterations. The page list interface is preserved to avoid requiring all users of the bulk API to allocate and manage enough storage to store the pages. Signed-off-by: Mel Gorman Acked-by: Vlastimil Babka --- include/linux/gfp.h | 13 +++++++--- mm/page_alloc.c | 60 +++++++++++++++++++++++++++++++++------------ 2 files changed, 54 insertions(+), 19 deletions(-) diff --git a/include/linux/gfp.h b/include/linux/gfp.h index 4a304fd39916..fb6234e1fe59 100644 --- a/include/linux/gfp.h +++ b/include/linux/gfp.h @@ -520,13 +520,20 @@ struct page *__alloc_pages(gfp_t gfp, unsigned int order, int preferred_nid, int __alloc_pages_bulk(gfp_t gfp, int preferred_nid, nodemask_t *nodemask, int nr_pages, - struct list_head *list); + struct list_head *page_list, + struct page **page_array); /* Bulk allocate order-0 pages */ static inline unsigned long -alloc_pages_bulk(gfp_t gfp, unsigned long nr_pages, struct list_head *list) +alloc_pages_bulk_list(gfp_t gfp, unsigned long nr_pages, struct list_head *list) { - return __alloc_pages_bulk(gfp, numa_mem_id(), NULL, nr_pages, list); + return __alloc_pages_bulk(gfp, numa_mem_id(), NULL, nr_pages, list, NULL); +} + +static inline unsigned long +alloc_pages_bulk_array(gfp_t gfp, unsigned long nr_pages, struct page **page_array) +{ + return __alloc_pages_bulk(gfp, numa_mem_id(), NULL, nr_pages, NULL, page_array); } /* diff --git a/mm/page_alloc.c b/mm/page_alloc.c index eb547470a7e4..be1e33a4df39 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -4966,21 +4966,29 @@ static inline bool prepare_alloc_pages(gfp_t gfp_mask, unsigned int order, } /* - * __alloc_pages_bulk - Allocate a number of order-0 pages to a list + * __alloc_pages_bulk - Allocate a number of order-0 pages to a list or array * @gfp: GFP flags for the allocation * @preferred_nid: The preferred NUMA node ID to allocate from * @nodemask: Set of nodes to allocate from, may be NULL - * @nr_pages: The number of pages desired on the list - * @page_list: List to store the allocated pages + * @nr_pages: The number of pages desired on the list or array + * @page_list: Optional list to store the allocated pages + * @page_array: Optional array to store the pages * * This is a batched version of the page allocator that attempts to - * allocate nr_pages quickly and add them to a list. + * allocate nr_pages quickly. Pages are added to page_list if page_list + * is not NULL, otherwise it is assumed that the page_array is valid. * - * Returns the number of pages on the list. + * For lists, nr_pages is the number of pages that should be allocated. + * + * For arrays, only NULL elements are populated with pages and nr_pages + * is the maximum number of pages that will be stored in the array. + * + * Returns the number of pages on the list or array. */ int __alloc_pages_bulk(gfp_t gfp, int preferred_nid, nodemask_t *nodemask, int nr_pages, - struct list_head *page_list) + struct list_head *page_list, + struct page **page_array) { struct page *page; unsigned long flags; @@ -4991,13 +4999,20 @@ int __alloc_pages_bulk(gfp_t gfp, int preferred_nid, struct alloc_context ac; gfp_t alloc_gfp; unsigned int alloc_flags; - int allocated = 0; + int nr_populated = 0; if (WARN_ON_ONCE(nr_pages <= 0)) return 0; + /* + * Skip populated array elements to determine if any pages need + * to be allocated before disabling IRQs. + */ + while (page_array && page_array[nr_populated] && nr_populated < nr_pages) + nr_populated++; + /* Use the single page allocator for one page. */ - if (nr_pages == 1) + if (nr_pages - nr_populated == 1) goto failed; /* May set ALLOC_NOFRAGMENT, fragmentation will return 1 page. */ @@ -5041,12 +5056,19 @@ int __alloc_pages_bulk(gfp_t gfp, int preferred_nid, pcp = &this_cpu_ptr(zone->pageset)->pcp; pcp_list = &pcp->lists[ac.migratetype]; - while (allocated < nr_pages) { + while (nr_populated < nr_pages) { + + /* Skip existing pages */ + if (page_array && page_array[nr_populated]) { + nr_populated++; + continue; + } + page = __rmqueue_pcplist(zone, ac.migratetype, alloc_flags, pcp, pcp_list); if (!page) { /* Try and get at least one page */ - if (!allocated) + if (!nr_populated) goto failed_irq; break; } @@ -5061,13 +5083,16 @@ int __alloc_pages_bulk(gfp_t gfp, int preferred_nid, zone_statistics(ac.preferred_zoneref->zone, zone); prep_new_page(page, 0, gfp, 0); - list_add(&page->lru, page_list); - allocated++; + if (page_list) + list_add(&page->lru, page_list); + else + page_array[nr_populated] = page; + nr_populated++; } local_irq_restore(flags); - return allocated; + return nr_populated; failed_irq: local_irq_restore(flags); @@ -5075,11 +5100,14 @@ int __alloc_pages_bulk(gfp_t gfp, int preferred_nid, failed: page = __alloc_pages(gfp, 0, preferred_nid, nodemask); if (page) { - list_add(&page->lru, page_list); - allocated = 1; + if (page_list) + list_add(&page->lru, page_list); + else + page_array[nr_populated] = page; + nr_populated++; } - return allocated; + return nr_populated; } EXPORT_SYMBOL_GPL(__alloc_pages_bulk); From patchwork Thu Mar 25 11:42:23 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mel Gorman X-Patchwork-Id: 12163803 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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,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 811CCC433E2 for ; Thu, 25 Mar 2021 11:44:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 562E26191D for ; Thu, 25 Mar 2021 11:44:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230478AbhCYLnj (ORCPT ); Thu, 25 Mar 2021 07:43:39 -0400 Received: from outbound-smtp13.blacknight.com ([46.22.139.230]:34733 "EHLO outbound-smtp13.blacknight.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231264AbhCYLnW (ORCPT ); Thu, 25 Mar 2021 07:43:22 -0400 Received: from mail.blacknight.com (pemlinmail01.blacknight.ie [81.17.254.10]) by outbound-smtp13.blacknight.com (Postfix) with ESMTPS id 97EA11C35AC for ; Thu, 25 Mar 2021 11:43:20 +0000 (GMT) Received: (qmail 17095 invoked from network); 25 Mar 2021 11:43:20 -0000 Received: from unknown (HELO stampy.112glenside.lan) (mgorman@techsingularity.net@[84.203.22.4]) by 81.17.254.9 with ESMTPA; 25 Mar 2021 11:43:20 -0000 From: Mel Gorman To: Andrew Morton Cc: Chuck Lever , Jesper Dangaard Brouer , Christoph Hellwig , Alexander Duyck , Vlastimil Babka , Matthew Wilcox , Ilias Apalodimas , LKML , Linux-Net , Linux-MM , Linux-NFS , Mel Gorman Subject: [PATCH 4/9] mm/page_alloc: optimize code layout for __alloc_pages_bulk Date: Thu, 25 Mar 2021 11:42:23 +0000 Message-Id: <20210325114228.27719-5-mgorman@techsingularity.net> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20210325114228.27719-1-mgorman@techsingularity.net> References: <20210325114228.27719-1-mgorman@techsingularity.net> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org From: Jesper Dangaard Brouer Looking at perf-report and ASM-code for __alloc_pages_bulk() it is clear that the code activated is suboptimal. The compiler guesses wrong and places unlikely code at the beginning. Due to the use of WARN_ON_ONCE() macro the UD2 asm instruction is added to the code, which confuse the I-cache prefetcher in the CPU. [mgorman: Minor changes and rebasing] Signed-off-by: Jesper Dangaard Brouer Signed-off-by: Mel Gorman Acked-By: Vlastimil Babka --- mm/page_alloc.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index be1e33a4df39..1ec18121268b 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -5001,7 +5001,7 @@ int __alloc_pages_bulk(gfp_t gfp, int preferred_nid, unsigned int alloc_flags; int nr_populated = 0; - if (WARN_ON_ONCE(nr_pages <= 0)) + if (unlikely(nr_pages <= 0)) return 0; /* @@ -5048,7 +5048,7 @@ int __alloc_pages_bulk(gfp_t gfp, int preferred_nid, * If there are no allowed local zones that meets the watermarks then * try to allocate a single page and reclaim if necessary. */ - if (!zone) + if (unlikely(!zone)) goto failed; /* Attempt the batch allocation */ @@ -5066,7 +5066,7 @@ int __alloc_pages_bulk(gfp_t gfp, int preferred_nid, page = __rmqueue_pcplist(zone, ac.migratetype, alloc_flags, pcp, pcp_list); - if (!page) { + if (unlikely(!page)) { /* Try and get at least one page */ if (!nr_populated) goto failed_irq; From patchwork Thu Mar 25 11:42:24 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mel Gorman X-Patchwork-Id: 12163811 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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 8FF85C433E2 for ; Thu, 25 Mar 2021 11:44:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4A23E61A2C for ; Thu, 25 Mar 2021 11:44:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231219AbhCYLoC (ORCPT ); Thu, 25 Mar 2021 07:44:02 -0400 Received: from outbound-smtp17.blacknight.com ([46.22.139.234]:52169 "EHLO outbound-smtp17.blacknight.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231474AbhCYLne (ORCPT ); Thu, 25 Mar 2021 07:43:34 -0400 Received: from mail.blacknight.com (pemlinmail01.blacknight.ie [81.17.254.10]) by outbound-smtp17.blacknight.com (Postfix) with ESMTPS id D0A2C1C35AC for ; Thu, 25 Mar 2021 11:43:30 +0000 (GMT) Received: (qmail 17676 invoked from network); 25 Mar 2021 11:43:30 -0000 Received: from unknown (HELO stampy.112glenside.lan) (mgorman@techsingularity.net@[84.203.22.4]) by 81.17.254.9 with ESMTPA; 25 Mar 2021 11:43:30 -0000 From: Mel Gorman To: Andrew Morton Cc: Chuck Lever , Jesper Dangaard Brouer , Christoph Hellwig , Alexander Duyck , Vlastimil Babka , Matthew Wilcox , Ilias Apalodimas , LKML , Linux-Net , Linux-MM , Linux-NFS , Mel Gorman Subject: [PATCH 5/9] mm/page_alloc: inline __rmqueue_pcplist Date: Thu, 25 Mar 2021 11:42:24 +0000 Message-Id: <20210325114228.27719-6-mgorman@techsingularity.net> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20210325114228.27719-1-mgorman@techsingularity.net> References: <20210325114228.27719-1-mgorman@techsingularity.net> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org From: Jesper Dangaard Brouer When __alloc_pages_bulk() got introduced two callers of __rmqueue_pcplist exist and the compiler chooses to not inline this function. ./scripts/bloat-o-meter vmlinux-before vmlinux-inline__rmqueue_pcplist add/remove: 0/1 grow/shrink: 2/0 up/down: 164/-125 (39) Function old new delta rmqueue 2197 2296 +99 __alloc_pages_bulk 1921 1986 +65 __rmqueue_pcplist 125 - -125 Total: Before=19374127, After=19374166, chg +0.00% modprobe page_bench04_bulk loops=$((10**7)) Type:time_bulk_page_alloc_free_array - Per elem: 106 cycles(tsc) 29.595 ns (step:64) - (measurement period time:0.295955434 sec time_interval:295955434) - (invoke count:10000000 tsc_interval:1065447105) Before: - Per elem: 110 cycles(tsc) 30.633 ns (step:64) Signed-off-by: Jesper Dangaard Brouer Signed-off-by: Mel Gorman Acked-by: Vlastimil Babka --- mm/page_alloc.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 1ec18121268b..d900e92884b2 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -3415,7 +3415,8 @@ static inline void zone_statistics(struct zone *preferred_zone, struct zone *z) } /* Remove page from the per-cpu list, caller must protect the list */ -static struct page *__rmqueue_pcplist(struct zone *zone, int migratetype, +static inline +struct page *__rmqueue_pcplist(struct zone *zone, int migratetype, unsigned int alloc_flags, struct per_cpu_pages *pcp, struct list_head *list) From patchwork Thu Mar 25 11:42:25 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mel Gorman X-Patchwork-Id: 12163809 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=-21.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS,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 E57B8C433DB for ; Thu, 25 Mar 2021 11:44:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B7D8C61A0A for ; Thu, 25 Mar 2021 11:44:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230185AbhCYLoF (ORCPT ); Thu, 25 Mar 2021 07:44:05 -0400 Received: from outbound-smtp26.blacknight.com ([81.17.249.194]:56019 "EHLO outbound-smtp26.blacknight.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231488AbhCYLnn (ORCPT ); Thu, 25 Mar 2021 07:43:43 -0400 Received: from mail.blacknight.com (pemlinmail01.blacknight.ie [81.17.254.10]) by outbound-smtp26.blacknight.com (Postfix) with ESMTPS id 0A662CAB58 for ; Thu, 25 Mar 2021 11:43:41 +0000 (GMT) Received: (qmail 18382 invoked from network); 25 Mar 2021 11:43:40 -0000 Received: from unknown (HELO stampy.112glenside.lan) (mgorman@techsingularity.net@[84.203.22.4]) by 81.17.254.9 with ESMTPA; 25 Mar 2021 11:43:40 -0000 From: Mel Gorman To: Andrew Morton Cc: Chuck Lever , Jesper Dangaard Brouer , Christoph Hellwig , Alexander Duyck , Vlastimil Babka , Matthew Wilcox , Ilias Apalodimas , LKML , Linux-Net , Linux-MM , Linux-NFS , Mel Gorman Subject: [PATCH 6/9] SUNRPC: Set rq_page_end differently Date: Thu, 25 Mar 2021 11:42:25 +0000 Message-Id: <20210325114228.27719-7-mgorman@techsingularity.net> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20210325114228.27719-1-mgorman@techsingularity.net> References: <20210325114228.27719-1-mgorman@techsingularity.net> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org From: Chuck Lever Patch series "SUNRPC consumer for the bulk page allocator" This patch set and the measurements below are based on yesterday's bulk allocator series: git://git.kernel.org/pub/scm/linux/kernel/git/mel/linux.git mm-bulk-rebase-v5r9 The patches change SUNRPC to invoke the array-based bulk allocator instead of alloc_page(). The micro-benchmark results are promising. I ran a mixture of 256KB reads and writes over NFSv3. The server's kernel is built with KASAN enabled, so the comparison is exaggerated but I believe it is still valid. I instrumented svc_recv() to measure the latency of each call to svc_alloc_arg() and report it via a trace point. The following results are averages across the trace events. Single page: 25.007 us per call over 532,571 calls Bulk list: 6.258 us per call over 517,034 calls Bulk array: 4.590 us per call over 517,442 calls This patch (of 2) Refactor: I'm about to use the loop variable @i for something else. As far as the "i++" is concerned, that is a post-increment. The value of @i is not used subsequently, so the increment operator is unnecessary and can be removed. Also note that nfsd_read_actor() was renamed nfsd_splice_actor() by commit cf8208d0eabd ("sendfile: convert nfsd to splice_direct_to_actor()"). Signed-off-by: Chuck Lever Signed-off-by: Mel Gorman --- net/sunrpc/svc_xprt.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/net/sunrpc/svc_xprt.c b/net/sunrpc/svc_xprt.c index 3cdd71a8df1e..609bda97d4ae 100644 --- a/net/sunrpc/svc_xprt.c +++ b/net/sunrpc/svc_xprt.c @@ -642,7 +642,7 @@ static void svc_check_conn_limits(struct svc_serv *serv) static int svc_alloc_arg(struct svc_rqst *rqstp) { struct svc_serv *serv = rqstp->rq_server; - struct xdr_buf *arg; + struct xdr_buf *arg = &rqstp->rq_arg; int pages; int i; @@ -667,11 +667,10 @@ static int svc_alloc_arg(struct svc_rqst *rqstp) } rqstp->rq_pages[i] = p; } - rqstp->rq_page_end = &rqstp->rq_pages[i]; - rqstp->rq_pages[i++] = NULL; /* this might be seen in nfs_read_actor */ + rqstp->rq_page_end = &rqstp->rq_pages[pages]; + rqstp->rq_pages[pages] = NULL; /* this might be seen in nfsd_splice_actor() */ /* Make arg->head point to first page and arg->pages point to rest */ - arg = &rqstp->rq_arg; arg->head[0].iov_base = page_address(rqstp->rq_pages[0]); arg->head[0].iov_len = PAGE_SIZE; arg->pages = rqstp->rq_pages + 1; From patchwork Thu Mar 25 11:42:26 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mel Gorman X-Patchwork-Id: 12163813 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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,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 33D36C433E1 for ; Thu, 25 Mar 2021 11:44:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EFDE56191D for ; Thu, 25 Mar 2021 11:44:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231241AbhCYLoG (ORCPT ); Thu, 25 Mar 2021 07:44:06 -0400 Received: from outbound-smtp14.blacknight.com ([46.22.139.231]:39027 "EHLO outbound-smtp14.blacknight.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231654AbhCYLnx (ORCPT ); Thu, 25 Mar 2021 07:43:53 -0400 Received: from mail.blacknight.com (pemlinmail01.blacknight.ie [81.17.254.10]) by outbound-smtp14.blacknight.com (Postfix) with ESMTPS id 4C42E1C35C3 for ; Thu, 25 Mar 2021 11:43:51 +0000 (GMT) Received: (qmail 19111 invoked from network); 25 Mar 2021 11:43:51 -0000 Received: from unknown (HELO stampy.112glenside.lan) (mgorman@techsingularity.net@[84.203.22.4]) by 81.17.254.9 with ESMTPA; 25 Mar 2021 11:43:51 -0000 From: Mel Gorman To: Andrew Morton Cc: Chuck Lever , Jesper Dangaard Brouer , Christoph Hellwig , Alexander Duyck , Vlastimil Babka , Matthew Wilcox , Ilias Apalodimas , LKML , Linux-Net , Linux-MM , Linux-NFS , Mel Gorman Subject: [PATCH 7/9] SUNRPC: Refresh rq_pages using a bulk page allocator Date: Thu, 25 Mar 2021 11:42:26 +0000 Message-Id: <20210325114228.27719-8-mgorman@techsingularity.net> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20210325114228.27719-1-mgorman@techsingularity.net> References: <20210325114228.27719-1-mgorman@techsingularity.net> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org From: Chuck Lever Reduce the rate at which nfsd threads hammer on the page allocator. This improves throughput scalability by enabling the threads to run more independently of each other. [mgorman: Update interpretation of alloc_pages_bulk return value] Signed-off-by: Chuck Lever Signed-off-by: Mel Gorman --- net/sunrpc/svc_xprt.c | 31 +++++++++++++++---------------- 1 file changed, 15 insertions(+), 16 deletions(-) diff --git a/net/sunrpc/svc_xprt.c b/net/sunrpc/svc_xprt.c index 609bda97d4ae..0c27c3291ca1 100644 --- a/net/sunrpc/svc_xprt.c +++ b/net/sunrpc/svc_xprt.c @@ -643,30 +643,29 @@ static int svc_alloc_arg(struct svc_rqst *rqstp) { struct svc_serv *serv = rqstp->rq_server; struct xdr_buf *arg = &rqstp->rq_arg; - int pages; - int i; + unsigned long pages, filled; - /* now allocate needed pages. If we get a failure, sleep briefly */ pages = (serv->sv_max_mesg + 2 * PAGE_SIZE) >> PAGE_SHIFT; if (pages > RPCSVC_MAXPAGES) { - pr_warn_once("svc: warning: pages=%u > RPCSVC_MAXPAGES=%lu\n", + pr_warn_once("svc: warning: pages=%lu > RPCSVC_MAXPAGES=%lu\n", pages, RPCSVC_MAXPAGES); /* use as many pages as possible */ pages = RPCSVC_MAXPAGES; } - for (i = 0; i < pages ; i++) - while (rqstp->rq_pages[i] == NULL) { - struct page *p = alloc_page(GFP_KERNEL); - if (!p) { - set_current_state(TASK_INTERRUPTIBLE); - if (signalled() || kthread_should_stop()) { - set_current_state(TASK_RUNNING); - return -EINTR; - } - schedule_timeout(msecs_to_jiffies(500)); - } - rqstp->rq_pages[i] = p; + + for (;;) { + filled = alloc_pages_bulk_array(GFP_KERNEL, pages, + rqstp->rq_pages); + if (filled == pages) + break; + + set_current_state(TASK_INTERRUPTIBLE); + if (signalled() || kthread_should_stop()) { + set_current_state(TASK_RUNNING); + return -EINTR; } + schedule_timeout(msecs_to_jiffies(500)); + } rqstp->rq_page_end = &rqstp->rq_pages[pages]; rqstp->rq_pages[pages] = NULL; /* this might be seen in nfsd_splice_actor() */ From patchwork Thu Mar 25 11:42:27 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mel Gorman X-Patchwork-Id: 12163815 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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,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 C5B75C433DB for ; Thu, 25 Mar 2021 11:45:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8AEBF619FF for ; Thu, 25 Mar 2021 11:45:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230434AbhCYLof (ORCPT ); Thu, 25 Mar 2021 07:44:35 -0400 Received: from outbound-smtp62.blacknight.com ([46.22.136.251]:49373 "EHLO outbound-smtp62.blacknight.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231193AbhCYLoC (ORCPT ); Thu, 25 Mar 2021 07:44:02 -0400 Received: from mail.blacknight.com (pemlinmail01.blacknight.ie [81.17.254.10]) by outbound-smtp62.blacknight.com (Postfix) with ESMTPS id 8A709FA826 for ; Thu, 25 Mar 2021 11:44:01 +0000 (GMT) Received: (qmail 19650 invoked from network); 25 Mar 2021 11:44:01 -0000 Received: from unknown (HELO stampy.112glenside.lan) (mgorman@techsingularity.net@[84.203.22.4]) by 81.17.254.9 with ESMTPA; 25 Mar 2021 11:44:01 -0000 From: Mel Gorman To: Andrew Morton Cc: Chuck Lever , Jesper Dangaard Brouer , Christoph Hellwig , Alexander Duyck , Vlastimil Babka , Matthew Wilcox , Ilias Apalodimas , LKML , Linux-Net , Linux-MM , Linux-NFS , Mel Gorman Subject: [PATCH 8/9] net: page_pool: refactor dma_map into own function page_pool_dma_map Date: Thu, 25 Mar 2021 11:42:27 +0000 Message-Id: <20210325114228.27719-9-mgorman@techsingularity.net> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20210325114228.27719-1-mgorman@techsingularity.net> References: <20210325114228.27719-1-mgorman@techsingularity.net> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org From: Jesper Dangaard Brouer In preparation for next patch, move the dma mapping into its own function, as this will make it easier to follow the changes. [ilias.apalodimas: make page_pool_dma_map return boolean] Signed-off-by: Jesper Dangaard Brouer Reviewed-by: Ilias Apalodimas Signed-off-by: Mel Gorman --- net/core/page_pool.c | 45 +++++++++++++++++++++++++------------------- 1 file changed, 26 insertions(+), 19 deletions(-) diff --git a/net/core/page_pool.c b/net/core/page_pool.c index ad8b0707af04..40e1b2beaa6c 100644 --- a/net/core/page_pool.c +++ b/net/core/page_pool.c @@ -180,14 +180,37 @@ static void page_pool_dma_sync_for_device(struct page_pool *pool, pool->p.dma_dir); } +static bool page_pool_dma_map(struct page_pool *pool, struct page *page) +{ + dma_addr_t dma; + + /* Setup DMA mapping: use 'struct page' area for storing DMA-addr + * since dma_addr_t can be either 32 or 64 bits and does not always fit + * into page private data (i.e 32bit cpu with 64bit DMA caps) + * This mapping is kept for lifetime of page, until leaving pool. + */ + dma = dma_map_page_attrs(pool->p.dev, page, 0, + (PAGE_SIZE << pool->p.order), + pool->p.dma_dir, DMA_ATTR_SKIP_CPU_SYNC); + if (dma_mapping_error(pool->p.dev, dma)) + return false; + + page->dma_addr = dma; + + if (pool->p.flags & PP_FLAG_DMA_SYNC_DEV) + page_pool_dma_sync_for_device(pool, page, pool->p.max_len); + + return true; +} + /* slow path */ noinline static struct page *__page_pool_alloc_pages_slow(struct page_pool *pool, gfp_t _gfp) { + unsigned int pp_flags = pool->p.flags; struct page *page; gfp_t gfp = _gfp; - dma_addr_t dma; /* We could always set __GFP_COMP, and avoid this branch, as * prep_new_page() can handle order-0 with __GFP_COMP. @@ -211,30 +234,14 @@ static struct page *__page_pool_alloc_pages_slow(struct page_pool *pool, if (!page) return NULL; - if (!(pool->p.flags & PP_FLAG_DMA_MAP)) - goto skip_dma_map; - - /* Setup DMA mapping: use 'struct page' area for storing DMA-addr - * since dma_addr_t can be either 32 or 64 bits and does not always fit - * into page private data (i.e 32bit cpu with 64bit DMA caps) - * This mapping is kept for lifetime of page, until leaving pool. - */ - dma = dma_map_page_attrs(pool->p.dev, page, 0, - (PAGE_SIZE << pool->p.order), - pool->p.dma_dir, DMA_ATTR_SKIP_CPU_SYNC); - if (dma_mapping_error(pool->p.dev, dma)) { + if ((pp_flags & PP_FLAG_DMA_MAP) && + unlikely(!page_pool_dma_map(pool, page))) { put_page(page); return NULL; } - page->dma_addr = dma; - if (pool->p.flags & PP_FLAG_DMA_SYNC_DEV) - page_pool_dma_sync_for_device(pool, page, pool->p.max_len); - -skip_dma_map: /* Track how many pages are held 'in-flight' */ pool->pages_state_hold_cnt++; - trace_page_pool_state_hold(pool, page, pool->pages_state_hold_cnt); /* When page just alloc'ed is should/must have refcnt 1. */ From patchwork Thu Mar 25 11:42:28 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mel Gorman X-Patchwork-Id: 12163817 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=-21.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_HELO_NONE,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 0BBD9C433C1 for ; Thu, 25 Mar 2021 11:45:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BE1A261A2C for ; Thu, 25 Mar 2021 11:45:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231193AbhCYLoh (ORCPT ); Thu, 25 Mar 2021 07:44:37 -0400 Received: from outbound-smtp02.blacknight.com ([81.17.249.8]:54600 "EHLO outbound-smtp02.blacknight.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231233AbhCYLoR (ORCPT ); Thu, 25 Mar 2021 07:44:17 -0400 Received: from mail.blacknight.com (pemlinmail01.blacknight.ie [81.17.254.10]) by outbound-smtp02.blacknight.com (Postfix) with ESMTPS id CC763BAA3C for ; Thu, 25 Mar 2021 11:44:11 +0000 (GMT) Received: (qmail 20297 invoked from network); 25 Mar 2021 11:44:11 -0000 Received: from unknown (HELO stampy.112glenside.lan) (mgorman@techsingularity.net@[84.203.22.4]) by 81.17.254.9 with ESMTPA; 25 Mar 2021 11:44:11 -0000 From: Mel Gorman To: Andrew Morton Cc: Chuck Lever , Jesper Dangaard Brouer , Christoph Hellwig , Alexander Duyck , Vlastimil Babka , Matthew Wilcox , Ilias Apalodimas , LKML , Linux-Net , Linux-MM , Linux-NFS , Mel Gorman Subject: [PATCH 9/9] net: page_pool: use alloc_pages_bulk in refill code path Date: Thu, 25 Mar 2021 11:42:28 +0000 Message-Id: <20210325114228.27719-10-mgorman@techsingularity.net> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20210325114228.27719-1-mgorman@techsingularity.net> References: <20210325114228.27719-1-mgorman@techsingularity.net> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org From: Jesper Dangaard Brouer There are cases where the page_pool need to refill with pages from the page allocator. Some workloads cause the page_pool to release pages instead of recycling these pages. For these workload it can improve performance to bulk alloc pages from the page-allocator to refill the alloc cache. For XDP-redirect workload with 100G mlx5 driver (that use page_pool) redirecting xdp_frame packets into a veth, that does XDP_PASS to create an SKB from the xdp_frame, which then cannot return the page to the page_pool. Performance results under GitHub xdp-project[1]: [1] https://github.com/xdp-project/xdp-project/blob/master/areas/mem/page_pool06_alloc_pages_bulk.org Mel: The patch "net: page_pool: convert to use alloc_pages_bulk_array variant" was squashed with this patch. From the test page, the array variant was superior with one of the test results as follows. Kernel XDP stats CPU pps Delta Baseline XDP-RX CPU total 3,771,046 n/a List XDP-RX CPU total 3,940,242 +4.49% Array XDP-RX CPU total 4,249,224 +12.68% Signed-off-by: Jesper Dangaard Brouer Signed-off-by: Mel Gorman Reviewed-by: Alexander Lobakin --- include/net/page_pool.h | 2 +- net/core/page_pool.c | 82 ++++++++++++++++++++++++++++------------- 2 files changed, 57 insertions(+), 27 deletions(-) diff --git a/include/net/page_pool.h b/include/net/page_pool.h index b5b195305346..6d517a37c18b 100644 --- a/include/net/page_pool.h +++ b/include/net/page_pool.h @@ -65,7 +65,7 @@ #define PP_ALLOC_CACHE_REFILL 64 struct pp_alloc_cache { u32 count; - void *cache[PP_ALLOC_CACHE_SIZE]; + struct page *cache[PP_ALLOC_CACHE_SIZE]; }; struct page_pool_params { diff --git a/net/core/page_pool.c b/net/core/page_pool.c index 40e1b2beaa6c..9ec1aa9640ad 100644 --- a/net/core/page_pool.c +++ b/net/core/page_pool.c @@ -203,38 +203,17 @@ static bool page_pool_dma_map(struct page_pool *pool, struct page *page) return true; } -/* slow path */ -noinline -static struct page *__page_pool_alloc_pages_slow(struct page_pool *pool, - gfp_t _gfp) +static struct page *__page_pool_alloc_page_order(struct page_pool *pool, + gfp_t gfp) { - unsigned int pp_flags = pool->p.flags; struct page *page; - gfp_t gfp = _gfp; - - /* We could always set __GFP_COMP, and avoid this branch, as - * prep_new_page() can handle order-0 with __GFP_COMP. - */ - if (pool->p.order) - gfp |= __GFP_COMP; - - /* FUTURE development: - * - * Current slow-path essentially falls back to single page - * allocations, which doesn't improve performance. This code - * need bulk allocation support from the page allocator code. - */ - /* Cache was empty, do real allocation */ -#ifdef CONFIG_NUMA + gfp |= __GFP_COMP; page = alloc_pages_node(pool->p.nid, gfp, pool->p.order); -#else - page = alloc_pages(gfp, pool->p.order); -#endif - if (!page) + if (unlikely(!page)) return NULL; - if ((pp_flags & PP_FLAG_DMA_MAP) && + if ((pool->p.flags & PP_FLAG_DMA_MAP) && unlikely(!page_pool_dma_map(pool, page))) { put_page(page); return NULL; @@ -243,6 +222,57 @@ static struct page *__page_pool_alloc_pages_slow(struct page_pool *pool, /* Track how many pages are held 'in-flight' */ pool->pages_state_hold_cnt++; trace_page_pool_state_hold(pool, page, pool->pages_state_hold_cnt); + return page; +} + +/* slow path */ +noinline +static struct page *__page_pool_alloc_pages_slow(struct page_pool *pool, + gfp_t gfp) +{ + const int bulk = PP_ALLOC_CACHE_REFILL; + unsigned int pp_flags = pool->p.flags; + unsigned int pp_order = pool->p.order; + struct page *page; + int i, nr_pages; + + /* Don't support bulk alloc for high-order pages */ + if (unlikely(pp_order)) + return __page_pool_alloc_page_order(pool, gfp); + + /* Unnecessary as alloc cache is empty, but guarantees zero count */ + if (unlikely(pool->alloc.count > 0)) + return pool->alloc.cache[--pool->alloc.count]; + + /* Mark empty alloc.cache slots "empty" for alloc_pages_bulk_array */ + memset(&pool->alloc.cache, 0, sizeof(void *) * bulk); + + nr_pages = alloc_pages_bulk_array(gfp, bulk, pool->alloc.cache); + if (unlikely(!nr_pages)) + return NULL; + + /* Pages have been filled into alloc.cache array, but count is zero and + * page element have not been (possibly) DMA mapped. + */ + for (i = 0; i < nr_pages; i++) { + page = pool->alloc.cache[i]; + if ((pp_flags & PP_FLAG_DMA_MAP) && + unlikely(!page_pool_dma_map(pool, page))) { + put_page(page); + continue; + } + pool->alloc.cache[pool->alloc.count++] = page; + /* Track how many pages are held 'in-flight' */ + pool->pages_state_hold_cnt++; + trace_page_pool_state_hold(pool, page, + pool->pages_state_hold_cnt); + } + + /* Return last page */ + if (likely(pool->alloc.count > 0)) + page = pool->alloc.cache[--pool->alloc.count]; + else + page = NULL; /* When page just alloc'ed is should/must have refcnt 1. */ return page;