On Fri, Jul 26, 2019 at 09:19:52PM -0700, Andrew Morton wrote: > On Fri, 26 Jul 2019 20:42:05 -0700 Nathan Chancellor <natechancellor@xxxxxxxxx> wrote: > > > > @@ -2414,8 +2414,9 @@ void mem_cgroup_handle_over_high(void) > > > */ > > > clamped_high = max(high, 1UL); > > > > > > - overage = ((u64)(usage - high) << MEMCG_DELAY_PRECISION_SHIFT) > > > - / clamped_high; > > > + overage = (u64)(usage - high) << MEMCG_DELAY_PRECISION_SHIFT; > > > + do_div(overage, clamped_high); > > > + > > > penalty_jiffies = ((u64)overage * overage * HZ) > > > >> (MEMCG_DELAY_PRECISION_SHIFT + MEMCG_DELAY_SCALING_SHIFT); > > > > > > _ > > > > > > > This causes a build error on arm: > > > > Ah. > > It's rather unclear why that u64 cast is there anyway. We're dealing > with ulongs all over this code. The below will suffice. I was thinking the same thing. > Chris, please take a look? > > --- a/mm/memcontrol.c~mm-throttle-allocators-when-failing-reclaim-over-memoryhigh-fix-fix-fix > +++ a/mm/memcontrol.c > @@ -2415,7 +2415,7 @@ void mem_cgroup_handle_over_high(void) > clamped_high = max(high, 1UL); > > overage = (u64)(usage - high) << MEMCG_DELAY_PRECISION_SHIFT; > - do_div(overage, clamped_high); > + overage /= clamped_high; > > penalty_jiffies = ((u64)overage * overage * HZ) > >> (MEMCG_DELAY_PRECISION_SHIFT + MEMCG_DELAY_SCALING_SHIFT); > _ > I assume this will get folded in with the original patch but for completeness (multi_v7_defconfig + CONFIG_MEMCG): Tested-by: Nathan Chancellor <natechancellor@xxxxxxxxx> Thanks for the quick fix!