Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755906Ab3IYXVy (ORCPT ); Wed, 25 Sep 2013 19:21:54 -0400 Received: from e23smtp08.au.ibm.com ([202.81.31.141]:38352 "EHLO e23smtp08.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755853Ab3IYXVw (ORCPT ); Wed, 25 Sep 2013 19:21:52 -0400 From: "Srivatsa S. Bhat" Subject: [RFC PATCH v4 16/40] mm: Introduce a "Region Allocator" to manage entire memory regions To: akpm@linux-foundation.org, mgorman@suse.de, dave@sr71.net, hannes@cmpxchg.org, tony.luck@intel.com, matthew.garrett@nebula.com, riel@redhat.com, arjan@linux.intel.com, srinivas.pandruvada@linux.intel.com, willy@linux.intel.com, kamezawa.hiroyu@jp.fujitsu.com, lenb@kernel.org, rjw@sisk.pl Cc: gargankita@gmail.com, paulmck@linux.vnet.ibm.com, svaidy@linux.vnet.ibm.com, andi@firstfloor.org, isimatu.yasuaki@jp.fujitsu.com, santosh.shilimkar@ti.com, kosaki.motohiro@gmail.com, srivatsa.bhat@linux.vnet.ibm.com, linux-pm@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Date: Thu, 26 Sep 2013 04:47:34 +0530 Message-ID: <20130925231730.26184.19552.stgit@srivatsabhat.in.ibm.com> In-Reply-To: <20130925231250.26184.31438.stgit@srivatsabhat.in.ibm.com> References: <20130925231250.26184.31438.stgit@srivatsabhat.in.ibm.com> User-Agent: StGIT/0.14.3 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-TM-AS-MML: No X-Content-Scanned: Fidelis XPS MAILER x-cbid: 13092523-5140-0000-0000-000003E41853 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4353 Lines: 132 Today, the MM subsystem uses the buddy 'Page Allocator' to manage memory at a 'page' granularity. But this allocator has no notion of the physical topology of the underlying memory hardware, and hence it is hard to influence memory allocation decisions keeping the platform constraints in mind. So we need to augment the page-allocator with a new entity to manage memory (at a much larger granularity) keeping the underlying platform characteristics and the memory hardware topology in mind. To that end, introduce a "Memory Region Allocator" as a backend to the existing "Page Allocator". Splitting the memory allocator into a Page-Allocator front-end and a Region-Allocator backend: Page Allocator | Memory Region Allocator - __ __ __ | ________ ________ |__|--|__|--|__|-- ... - | | | | ____ ____ ____ | | | | | |____|--|____|--|____|-- ... - | |--| |-- ... | | | | | - |________| |________| | - Manages pages using | Manages memory regions buddy freelists - (allocates and frees entire | memory regions, i.e., at a - memory-region granularity) The flow of memory allocations/frees between entities requesting memory (applications/kernel) and the MM subsystem: pages regions Applications <========> Page <========> Memory Region and Kernel Allocator Allocator Since the region allocator is supposed to function as a backend to the page allocator, we implement it on a per-zone basis (since the page-allocator is also per-zone). Signed-off-by: Srivatsa S. Bhat --- include/linux/mmzone.h | 17 +++++++++++++++++ mm/page_alloc.c | 19 +++++++++++++++++++ 2 files changed, 36 insertions(+) diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index 155c1a1..7c87518 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h @@ -112,6 +112,21 @@ struct free_area { unsigned long nr_free; }; +/* A simplified free_area for managing entire memory regions */ +struct free_area_region { + struct list_head list; + unsigned long nr_free; +}; + +struct mem_region { + struct free_area_region region_area[MAX_ORDER]; +}; + +struct region_allocator { + struct mem_region region[MAX_NR_ZONE_REGIONS]; + int next_region; +}; + struct pglist_data; /* @@ -405,6 +420,8 @@ struct zone { struct zone_mem_region zone_regions[MAX_NR_ZONE_REGIONS]; int nr_zone_regions; + struct region_allocator region_allocator; + #ifndef CONFIG_SPARSEMEM /* * Flags for a pageblock_nr_pages block. See pageblock-flags.h. diff --git a/mm/page_alloc.c b/mm/page_alloc.c index dc02a80..876c231 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -5240,6 +5240,23 @@ static void __meminit init_node_memory_regions(struct pglist_data *pgdat) pgdat->nr_node_regions = idx; } +static void __meminit init_zone_region_allocator(struct zone *zone) +{ + struct free_area_region *area; + int i, j; + + for (i = 0; i < zone->nr_zone_regions; i++) { + area = zone->region_allocator.region[i].region_area; + + for (j = 0; j < MAX_ORDER; j++) { + INIT_LIST_HEAD(&area[j].list); + area[j].nr_free = 0; + } + } + + zone->region_allocator.next_region = -1; +} + static void __meminit zone_init_free_lists_late(struct zone *zone) { struct mem_region_list *mr_list; @@ -5326,6 +5343,8 @@ static void __meminit init_zone_memory_regions(struct pglist_data *pgdat) zone_init_free_lists_late(z); + init_zone_region_allocator(z); + /* * Revisit the last visited node memory region, in case it * spans multiple zones. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/