From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752131AbdFHEcH (ORCPT ); Thu, 8 Jun 2017 00:32:07 -0400 Received: from userp1040.oracle.com ([156.151.31.81]:44309 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751969AbdFHEcG (ORCPT ); Thu, 8 Jun 2017 00:32:06 -0400 Subject: Re: [patch -mm] mm, hugetlb: schedule when potentially allocating many hugepages To: David Rientjes , Andrew Morton References: Cc: Naoya Horiguchi , "Aneesh Kumar K.V" , linux-kernel@vger.kernel.org, linux-mm@kvack.org From: Mike Kravetz Message-ID: <52ee0233-c3cd-d33a-a33b-50d49e050d5c@oracle.com> Date: Wed, 7 Jun 2017 21:31:57 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.8.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit X-Source-IP: userv0021.oracle.com [156.151.31.71] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 06/07/2017 09:03 PM, David Rientjes wrote: > A few hugetlb allocators loop while calling the page allocator and can > potentially prevent rescheduling if the page allocator slowpath is not > utilized. > > Conditionally schedule when large numbers of hugepages can be allocated. > > Signed-off-by: David Rientjes > --- > Based on -mm only to prevent merge conflicts with > "mm/hugetlb.c: warn the user when issues arise on boot due to hugepages" > > mm/hugetlb.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/mm/hugetlb.c b/mm/hugetlb.c > --- a/mm/hugetlb.c > +++ b/mm/hugetlb.c > @@ -1754,6 +1754,7 @@ static int gather_surplus_pages(struct hstate *h, int delta) > break; > } > list_add(&page->lru, &surplus_list); > + cond_resched(); > } > allocated += i; > > @@ -2222,6 +2223,7 @@ static void __init hugetlb_hstate_alloc_pages(struct hstate *h) > } else if (!alloc_fresh_huge_page(h, > &node_states[N_MEMORY])) > break; > + cond_resched(); > } > if (i < h->max_huge_pages) { > char buf[32]; > @@ -2364,6 +2366,7 @@ static unsigned long set_max_huge_pages(struct hstate *h, unsigned long count, > ret = alloc_fresh_gigantic_page(h, nodes_allowed); > else > ret = alloc_fresh_huge_page(h, nodes_allowed); > + cond_resched(); Are not the following lines immediately before the above huge page allocation in set_max_huge_pages, or am I looking at an incorrect version of the file? /* yield cpu to avoid soft lockup */ cond_resched(); -- Mike Kravetz > spin_lock(&hugetlb_lock); > if (!ret) > goto out; > > -- > 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 >