From 7672714c185c11de1aaa64d00a6bbcd2da5897ce Mon Sep 17 00:00:00 2001
From: David Rientjes <rientjes@google.com>
Date: Tue, 15 Aug 2017 12:01:03 -0700
Subject: [PATCH] mm, hugetlb: schedule when potentially allocating many hugepages
Git-commit: 69ed779a1454d9a57ba3738135eec9be550e0613
Patch-mainline: v4.13-rc1
References: bsc#971975
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.
Anshuman: "Fixes a task which was getting hung while writing like 10000 hugepages
(16MB on POWER8) into /proc/sys/vm/nr_hugepages."
Link: http://lkml.kernel.org/r/alpine.DEB.2.10.1706091535300.66176@chino.kir.corp.google.com
Signed-off-by: David Rientjes <rientjes@google.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Tested-by: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
---
mm/hugetlb.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 5fd32d05e328..12c419c5affb 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -1747,6 +1747,7 @@ static int gather_surplus_pages(struct hstate *h, int delta)
break;
}
list_add(&page->lru, &surplus_list);
+ cond_resched();
}
allocated += i;
@@ -2215,6 +2216,7 @@ static void __init hugetlb_hstate_alloc_pages(struct hstate *h)
} else if (!alloc_fresh_huge_page(h,
&node_states[N_MEMORY]))
break;
+ cond_resched();
}
h->max_huge_pages = i;
}
--
2.12.0