commit e3f1164fc9ee ("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: e3f1164fc9ee ("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 Closes: https://lore.kernel.org/linux-pm/40212796-734c-4140-8a85-854f72b8144d@panix.... Cc: stable@vger.kernel.org Signed-off-by: Christian Loehle christian.loehle@arm.com --- kernel/power/energy_model.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-)
diff --git a/kernel/power/energy_model.c b/kernel/power/energy_model.c index ea7995a25780..b63c2afc1379 100644 --- a/kernel/power/energy_model.c +++ b/kernel/power/energy_model.c @@ -778,7 +778,7 @@ 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"); @@ -796,10 +796,8 @@ 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);
@@ -814,6 +812,11 @@ static void em_check_capacity_update(void) em_adjust_new_capacity(cpu, dev, pd); }
+ if (failed_cpus) { + pr_debug("Accessing %d policies failed, retrying\n", failed_cpus); + schedule_delayed_work(&em_update_work, msecs_to_jiffies(1000)); + } + free_cpumask_var(cpu_done_mask); }