Re: [PATCH 28/33] arm_mpam: Track bandwidth counter state for overflow and power management
From: Fenghua Yu <fenghuay@nvidia.com>
Date: 2025-08-28 00:58:33
Also in:
linux-acpi, linux-devicetree, lkml
Hi, James, On 8/22/25 08:30, James Morse wrote:
Bandwidth counters need to run continuously to correctly reflect the bandwidth. The value read may be lower than the previous value read in the case of overflow and when the hardware is reset due to CPU hotplug. Add struct mbwu_state to track the bandwidth counter to allow overflow and power management to be handled. Signed-off-by: James Morse <james.morse@arm.com>
[SNIP]
quoted hunk ↗ jump to hunk
@@ -2291,11 +2395,35 @@ static void mpam_unregister_irqs(void) static void __destroy_component_cfg(struct mpam_component *comp) { + struct mpam_msc *msc; + struct mpam_vmsc *vmsc; + struct mpam_msc_ris *ris; + + lockdep_assert_held(&mpam_list_lock); + add_to_garbage(comp->cfg); + list_for_each_entry(vmsc, &comp->vmsc, comp_list) { + msc = vmsc->msc; + + mpam_mon_sel_outer_lock(msc); + if (mpam_mon_sel_inner_lock(msc)) { + list_for_each_entry(ris, &vmsc->ris, vmsc_list) + add_to_garbage(ris->mbwu_state); + mpam_mon_sel_inner_unlock(msc); + } + mpam_mon_sel_outer_lock(msc);
s/mpam_mon_sel_outer_lock(msc);/mpam_mon_sel_outer_unlock(msc);/ Or this will hit a dead lock. [SNIP] Thanks. -Fenghua