[PATCH v2 05/12] arm_mpam: Ensure MBWU counters are reset on restore
Gavin Shan
gshan at redhat.com
Mon Sep 21 22:43:00 PDT 2026
On 9/18/26 12:56 AM, Ben Horgan wrote:
> When an MSC becomes inaccessible due to cpu offline CFG_MBWU_CTL is set to
> zero in mpam_save_mbwu_state(). This is very likely to mean that the config
> will mismatch when restoring and so the monitor will be reset. However, the
> state may have been lost and so there are no guarantees. Ensure the reset
> happens by setting the reset_on_next_read and remove the unnecessary writes
> from mpam_save_mbwu_state().
>
> Fixes: 41e8a14950e1 ("arm_mpam: Track bandwidth counter state for power management")
> Signed-off-by: Ben Horgan <ben.horgan at arm.com>
> Tested-by: Gavin Shan <gshan at redhat.com>
> ---
> Changes since v1:
> Use local variable mbwu_state consistently (Shaopeng)
> Only access ris->mbwu_state when have the mon_sel_lock
> ---
> drivers/resctrl/mpam_devices.c | 17 +++++++++--------
> 1 file changed, 9 insertions(+), 8 deletions(-)
>
Reviewed-by: Gavin Shan <gshan at redhat.com>
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