Re: [PATCH 07/10] ARC: [plat-eznps] disabled stall counter due to a HW bug

From: Alexey Brodkin
Date: Thu May 25 2017 - 07:10:28 EST


Hi Noam,

On Thu, 2017-05-25 at 05:34 +0300, Noam Camus wrote:
> From: Noam Camus <noamca@xxxxxxxxxxxx>
>
> This counter represents threshold for consecutive stall that which
> trigger HW threads scheduling.
> Low values of this counter cause downgrade in performance
> and in the worst case even a livelock.
>
> Signed-off-by: Noam Camus <noamca@xxxxxxxxxxxx>
> ---
> Âarch/arc/plat-eznps/mtm.c |ÂÂÂÂ2 --
> Â1 files changed, 0 insertions(+), 2 deletions(-)
>
> diff --git a/arch/arc/plat-eznps/mtm.c b/arch/arc/plat-eznps/mtm.c
> index aaaaffd..e0cb36b 100644
> --- a/arch/arc/plat-eznps/mtm.c
> +++ b/arch/arc/plat-eznps/mtm.c
> @@ -119,8 +119,6 @@ void mtm_enable_core(unsigned int cpu)
> Â mt_ctrl.value = 0;
> Â mt_ctrl.hsen = 1;
> Â mt_ctrl.hs_cnt = MT_CTRL_HS_CNT;
> - mt_ctrl.sten = 1;
> - mt_ctrl.st_cnt = MT_CTRL_ST_CNT;

Even though I don't know your architecture this change doesn't
make enough sense to me in absence of better explanation of what is
really done here.

I.e. how removal of those 2 lines above improve your situation.

-Alexey