Re: [PATCH mpam mpam/snapshot/v6.14-rc1] arm64/mpam: Fix MBWU monitor overflow handling

[Zeng Heng]

Hi Ben,

On 2025/10/23 0:17, Ben Horgan wrote:

> > Signed-off-by: Zeng Heng <zengheng4@xxxxxxxxxx>
> > ---
> >   drivers/resctrl/mpam_devices.c | 8 +++++---
> >   1 file changed, 5 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/resctrl/mpam_devices.c b/drivers/resctrl/mpam_devices.c
> > index 0dd048279e02..06f3ec9887d2 100644
> > --- a/drivers/resctrl/mpam_devices.c
> > +++ b/drivers/resctrl/mpam_devices.c
> > @@ -1101,7 +1101,8 @@ static void __ris_msmon_read(void *arg)
> >   	clean_msmon_ctl_val(&cur_ctl);
> >   	gen_msmon_ctl_flt_vals(m, &ctl_val, &flt_val);
> >   	config_mismatch = cur_flt != flt_val ||
> > -			  cur_ctl != (ctl_val | MSMON_CFG_x_CTL_EN);
> > +			 (cur_ctl & ~MSMON_CFG_x_CTL_OFLOW_STATUS) !=
> > +			 (ctl_val | MSMON_CFG_x_CTL_EN);
>
> This only considers 31 bit counters. I would expect any change here to
> consider all lengths of counter. 

Sorry, regardless of whether the counter is 32-bit or 64-bit, the
config_mismatch logic should be handled the same way here. Am I
wrong?

Best Regards,
Zeng Heng