Commit 69ed779a authored Jul 10, 2017 by David Rientjes Committed by Linus Torvalds Jul 10, 2017

mm, hugetlb: schedule when potentially allocating many hugepages

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>

parent 8b913238

mm/hugetlb.c

+2 −0

Original line number	Diff line number	Diff line
		@@ -1781,6 +1781,7 @@ retry:
		break;
		}
		list_add(&page->lru, &surplus_list);
		cond_resched();
		}
		allocated += i;

		@@ -2249,6 +2250,7 @@ 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];

Admin message