On Thu 28-07-16 10:54:02, Jia He wrote: > In powerpc servers with large memory(32TB), we watched several soft > lockups for hugepage under stress tests. > The call trace are as follows: > 1. > get_page_from_freelist+0x2d8/0xd50 > __alloc_pages_nodemask+0x180/0xc20 > alloc_fresh_huge_page+0xb0/0x190 > set_max_huge_pages+0x164/0x3b0 > > 2. > prep_new_huge_page+0x5c/0x100 > alloc_fresh_huge_page+0xc8/0x190 > set_max_huge_pages+0x164/0x3b0 > > This patch is to fix such soft lockups. It is safe to call cond_resched() > there because it is out of spin_lock/unlock section. > > Signed-off-by: Jia He <[email protected]> > Cc: Andrew Morton <[email protected]> > Cc: Naoya Horiguchi <[email protected]> > Cc: Mike Kravetz <[email protected]> > Cc: "Kirill A. Shutemov" <[email protected]> > Cc: Michal Hocko <[email protected]> > Cc: Dave Hansen <[email protected]> > Cc: Paul Gortmaker <[email protected]>
Acked-by: Michal Hocko <[email protected]> > > --- > Changes in V2: move cond_resched to a common calling site in > set_max_huge_pages > > mm/hugetlb.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/mm/hugetlb.c b/mm/hugetlb.c > index abc1c5f..9284280 100644 > --- a/mm/hugetlb.c > +++ b/mm/hugetlb.c > @@ -2216,6 +2216,10 @@ static unsigned long set_max_huge_pages(struct hstate > *h, unsigned long count, > * and reducing the surplus. > */ > spin_unlock(&hugetlb_lock); > + > + /* yield cpu to avoid soft lockup */ > + cond_resched(); > + > if (hstate_is_gigantic(h)) > ret = alloc_fresh_gigantic_page(h, nodes_allowed); > else > -- > 2.5.0 > > -- > To unsubscribe, send a message with 'unsubscribe linux-mm' in > the body to [email protected]. For more info on Linux MM, > see: http://www.linux-mm.org/ . > Don't email: <a href=mailto:"[email protected]";> [email protected] </a> -- Michal Hocko SUSE Labs
