On Thu, Jul 28, 2016 at 10:54:02AM +0800, 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 <hejianet@xxxxxxxxx> > Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> > Cc: Naoya Horiguchi <n-horiguchi@xxxxxxxxxxxxx> > Cc: Mike Kravetz <mike.kravetz@xxxxxxxxxx> > Cc: "Kirill A. Shutemov" <kirill.shutemov@xxxxxxxxxxxxxxx> > Cc: Michal Hocko <mhocko@xxxxxxxx> > Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx> > Cc: Paul Gortmaker <paul.gortmaker@xxxxxxxxxxxxx> Looks good to me. Reviewed-by: Naoya Horiguchi <n-horiguchi@xxxxxxxxxxxxx> Thanks, Naoya Horiguchi > > --- > 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 majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href