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PM: EM: Fix late boot with holes in CPU topology

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Commit e3f1164fc9 ("PM: EM: Support late CPUs booting and capacity
adjustment") added a mechanism to handle CPUs that come up late by
retrying when any of the `cpufreq_cpu_get()` call fails.

However, if there are holes in the CPU topology (offline CPUs, e.g.
nosmt), the first missing CPU causes the loop to break, preventing
subsequent online CPUs from being updated.

Instead of aborting on the first missing CPU policy, loop through all
and retry if any were missing.

Fixes: e3f1164fc9 ("PM: EM: Support late CPUs booting and capacity adjustment")
Suggested-by: Kenneth Crudup <kenneth.crudup@gmail.com>
Reported-by: Kenneth Crudup <kenneth.crudup@gmail.com>
Link: https://lore.kernel.org/linux-pm/40212796-734c-4140-8a85-854f72b8144d@panix.com/
Cc: 6.9+ <stable@vger.kernel.org> # 6.9+
Signed-off-by: Christian Loehle <christian.loehle@arm.com>
Link: https://patch.msgid.link/20250831214357.2020076-1-christian.loehle@arm.com
[ rjw: Drop the new pr_debug() message which is not very useful ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This commit is contained in:
Christian Loehle
2025-08-31 22:43:57 +01:00
committed by Rafael J. Wysocki
parent e042354147
commit 1ebe8f7e78
1 changed files with 6 additions and 5 deletions
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11
kernel/power/energy_model.c
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@@ -799,7 +799,7 @@ void em_adjust_cpu_capacity(unsigned int cpu)
static void em_check_capacity_update(void)
{
cpumask_var_t cpu_done_mask;
int cpu;
int cpu, failed_cpus = 0;
if (!zalloc_cpumask_var(&cpu_done_mask, GFP_KERNEL)) {
pr_warn("no free memory\n");
@@ -817,10 +817,8 @@ static void em_check_capacity_update(void)
policy = cpufreq_cpu_get(cpu);
if (!policy) {
pr_debug("Accessing cpu%d policy failed\n", cpu);
schedule_delayed_work(&em_update_work,
msecs_to_jiffies(1000));
break;
failed_cpus++;
continue;
}
cpufreq_cpu_put(policy);
@@ -835,6 +833,9 @@ static void em_check_capacity_update(void)
em_adjust_new_capacity(cpu, dev, pd);
}
if (failed_cpus)
schedule_delayed_work(&em_update_work, msecs_to_jiffies(1000));
free_cpumask_var(cpu_done_mask);
}