From: Gavin Shan <gshan@redhat.com>
To: Ben Horgan <ben.horgan@arm.com>
Cc: james.morse@arm.com, reinette.chatre@intel.com,
fenghuay@nvidia.com, linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org, dave.martin@arm.com,
andre.przywara@arm.com
Subject: Re: [PATCH v2 05/12] arm_mpam: Ensure MBWU counters are reset on restore
Date: Tue, 22 Sep 2026 15:43:00 +1000 [thread overview]
Message-ID: <729c585e-2977-496f-aa7f-d68d9ccb9162@redhat.com> (raw)
In-Reply-To: <20260917145617.2202986-6-ben.horgan@arm.com>
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@arm.com>
> Tested-by: Gavin Shan <gshan@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@redhat.com>
next prev parent reply other threads:[~2026-09-22 5:43 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-09-17 14:56 [PATCH v2 00/12] arm_mpam: minor fixes at v7.2 Ben Horgan
2026-09-17 14:56 ` [PATCH v2 01/12] arm_mpam: Move MPAMF_ECR write helpers to allow reuse Ben Horgan
2026-09-22 5:41 ` Gavin Shan
2026-09-17 14:56 ` [PATCH v2 02/12] arm_mpam: Restore the error interrupt enable from mpam_cpu_online() Ben Horgan
2026-09-22 5:42 ` Gavin Shan
2026-09-17 14:56 ` [PATCH v2 03/12] arm_mpam: Set mpam_feat_msmon_mbwu_31counter when there are bandwidth counters Ben Horgan
2026-09-22 5:42 ` Gavin Shan
2026-09-17 14:56 ` [PATCH v2 04/12] arm_mpam: Add missing mon_sel locking in MBWU save and restore Ben Horgan
2026-09-17 14:56 ` [PATCH v2 05/12] arm_mpam: Ensure MBWU counters are reset on restore Ben Horgan
2026-09-22 5:43 ` Gavin Shan [this message]
2026-09-17 14:56 ` [PATCH v2 06/12] arm_mpam: Use __ris_msmon_read() for saving MBWU state Ben Horgan
2026-09-17 14:56 ` [PATCH v2 07/12] arm_mpam: Initialize all of struct mon_read in mpam_restore_mbwu_state() Ben Horgan
2026-09-17 14:56 ` [PATCH v2 08/12] arm_mpam: resctrl: Correct check that existing class is L3 Ben Horgan
2026-09-22 5:43 ` Gavin Shan
2026-09-17 14:56 ` [PATCH v2 09/12] arm_mpam: resctrl: Make read_mon_cdp_safe() self consistent Ben Horgan
2026-09-22 5:44 ` Gavin Shan
2026-09-17 14:56 ` [PATCH v2 10/12] arm_mpam: Don't loop forever if there is the maximum possible amount of PARTIDs Ben Horgan
2026-09-22 5:44 ` Gavin Shan
2026-09-17 14:56 ` [PATCH v2 11/12] arm_mpam: Switch to kvzmalloc_objs() for allocation of component cfg Ben Horgan
2026-09-22 5:45 ` Gavin Shan
2026-09-17 14:56 ` [PATCH v2 12/12] arm_mpam: resctrl: Don't stop early when tearing down a class Ben Horgan
2026-09-22 5:45 ` Gavin Shan
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