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author | Cannon Matthews <cannonmatthews@google.com> | 2018-07-04 02:02:43 +0200 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2018-07-04 02:32:19 +0200 |
commit | 520495fe96d74e05db585fc748351e0504d8f40d (patch) | |
tree | c0e3a926ecefc43e56bfc0b8d71e86e01f78f5c9 /mm | |
parent | userfaultfd: hugetlbfs: fix userfaultfd_huge_must_wait() pte access (diff) | |
download | linux-520495fe96d74e05db585fc748351e0504d8f40d.tar.xz linux-520495fe96d74e05db585fc748351e0504d8f40d.zip |
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@google.com
Signed-off-by: Cannon Matthews <cannonmatthews@google.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Andres Lagar-Cavilla <andreslc@google.com>
Cc: Peter Feiner <pfeiner@google.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm')
-rw-r--r-- | mm/hugetlb.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 3612fbb32e9d..039ddbc574e9 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -2163,6 +2163,7 @@ static void __init gather_bootmem_prealloc(void) */ if (hstate_is_gigantic(h)) adjust_managed_page_count(page, 1 << h->order); + cond_resched(); } } |