From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-it0-f71.google.com (mail-it0-f71.google.com [209.85.214.71]) by kanga.kvack.org (Postfix) with ESMTP id DF56F6B025E for ; Wed, 29 Nov 2017 14:09:34 -0500 (EST) Received: by mail-it0-f71.google.com with SMTP id w125so3973926itf.0 for ; Wed, 29 Nov 2017 11:09:34 -0800 (PST) Received: from aserp1040.oracle.com (aserp1040.oracle.com. [141.146.126.69]) by mx.google.com with ESMTPS id l187si2082612itb.54.2017.11.29.11.09.33 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 29 Nov 2017 11:09:33 -0800 (PST) Subject: Re: [PATCH RFC 1/2] mm, hugetlb: unify core page allocation accounting and initialization References: <20171128101907.jtjthykeuefxu7gl@dhcp22.suse.cz> <20171128141211.11117-1-mhocko@kernel.org> <20171128141211.11117-2-mhocko@kernel.org> <4c919c6d-2e97-b66d-f572-439bb9f0587b@oracle.com> <20171129065732.lm4yucdnaizr2mjb@dhcp22.suse.cz> From: Mike Kravetz Message-ID: Date: Wed, 29 Nov 2017 11:09:26 -0800 MIME-Version: 1.0 In-Reply-To: <20171129065732.lm4yucdnaizr2mjb@dhcp22.suse.cz> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Michal Hocko Cc: linux-mm@kvack.org, Naoya Horiguchi , LKML On 11/28/2017 10:57 PM, Michal Hocko wrote: > On Tue 28-11-17 13:34:53, Mike Kravetz wrote: >> On 11/28/2017 06:12 AM, Michal Hocko wrote: > [...] >>> +/* >>> + * Allocates a fresh page to the hugetlb allocator pool in the node interleaved >>> + * manner. >>> + */ >>> static int alloc_fresh_huge_page(struct hstate *h, nodemask_t *nodes_allowed) >>> { >>> struct page *page; >>> int nr_nodes, node; >>> - int ret = 0; >>> + gfp_t gfp_mask = htlb_alloc_mask(h) | __GFP_THISNODE; >>> >>> for_each_node_mask_to_alloc(h, nr_nodes, node, nodes_allowed) { >>> - page = alloc_fresh_huge_page_node(h, node); >>> - if (page) { >>> - ret = 1; >>> + page = __hugetlb_alloc_buddy_huge_page(h, gfp_mask, >>> + node, nodes_allowed); >> >> I don't have the greatest understanding of node/nodemasks, but ... >> Since __hugetlb_alloc_buddy_huge_page calls __alloc_pages_nodemask(), do >> we still need to explicitly iterate over nodes with >> for_each_node_mask_to_alloc() here? > > Yes we do, because callers depend on the round robin allocation policy > which is implemented by the ugly for_each_node_mask_to_alloc. I am not > saying I like the way this is done but this is user visible thing. Ah, thanks. I missed the __GFP_THISNODE. Because of that, the nodes_allowed mask is not used in the allocation attempts. So, cycling through the nodes with the for_each_node_mask_to_alloc makes sense. > Or maybe I've missunderstood the whole thing... No, this should preserve the original behavior. -- Mike Kravetz -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org