The patch titled
Subject: mm: hugetlb: yield when prepping struct pages
has been removed from the -mm tree. Its filename was
mm-hugetlb-yield-when-prepping-struct-pages.patch
This patch was dropped because it was merged into mainline or a subsystem tree
------------------------------------------------------
From: Cannon Matthews <cannonmatthews@xxxxxxxxxx>
Subject: mm: hugetlb: yield when prepping struct pages
When booting with very large numbers of gigantic (i.e. 1G) pages, the
operations in the loop of gather_bootmem_prealloc, and specifically
prep_compound_gigantic_page, takes a very long time, and can cause a
softlockup if enough pages are requested at boot.
For example booting with 3844 1G pages requires prepping
(set_compound_head, init the count) over 1 billion 4K tail pages, which
takes considerable time.
Add a cond_resched() to the outer loop in gather_bootmem_prealloc() to
prevent this lockup.
Tested: Booted with softlockup_panic=1 hugepagesz=1G hugepages=3844 and no
softlockup is reported, and the hugepages are reported as successfully
setup.
Link: http://lkml.kernel.org/r/20180627214447.260804-1-cannonmatthews@xxxxxxxxxx
Signed-off-by: Cannon Matthews <cannonmatthews@xxxxxxxxxx>
Reviewed-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Reviewed-by: Mike Kravetz <mike.kravetz@xxxxxxxxxx>
Acked-by: Michal Hocko <mhocko@xxxxxxxx>
Cc: Andres Lagar-Cavilla <andreslc@xxxxxxxxxx>
Cc: Peter Feiner <pfeiner@xxxxxxxxxx>
Cc: Greg Thelen <gthelen@xxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/hugetlb.c | 1 +
1 file changed, 1 insertion(+)
diff -puN mm/hugetlb.c~mm-hugetlb-yield-when-prepping-struct-pages mm/hugetlb.c
--- a/mm/hugetlb.c~mm-hugetlb-yield-when-prepping-struct-pages
+++ a/mm/hugetlb.c
@@ -2163,6 +2163,7 @@ static void __init gather_bootmem_preall
*/
if (hstate_is_gigantic(h))
adjust_managed_page_count(page, 1 << h->order);
+ cond_resched();
}
}
_
Patches currently in -mm which might be from cannonmatthews@xxxxxxxxxx are
