Re: [PATCH] psi-pressure-stall-information-for-cpu-memory-and-io-fix-fix-fix

From: Peter Zijlstra
Date: Tue Jul 17 2018 - 11:18:13 EST


On Tue, Jul 17, 2018 at 03:51:24PM +0200, Arnd Bergmann wrote:
> The addition of do_div() did not do the right thing, as it assigned the
> result of the multiplication to an 'unsigned long', which truncates
> it before the division. GCC warns in various ways about this depending
> on the architecuture, e.g.
>
> arch/arm/include/asm/div64.h:33:45: note: expected 'uint64_t *' {aka 'long long unsigned int *'} but argument is of type 'long unsigned int *'
>
> This uses div_u64() instead. This is probably still a bad idea since
> we should avoid 64-bit division altogether in the scheduler, but at
> least it does the correct calculation.
>
> Fixes: 13a67bcb35f5 ("psi-pressure-stall-information-for-cpu-memory-and-io-fix-fix")
> Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
> ---
> Please fold into the fix

Please drop the entire PSI series instead.