Hi Artem,
At 03/14/2018 11:29 AM, Dou Liyang wrote:
Hi All,
At 03/13/2018 05:35 PM, Rafael J. Wysocki wrote:
On Tue, Mar 13, 2018 at 9:39 AM, Artem Bityutskiy
<dedekind1@xxxxxxxxx> wrote:
On Tue, 2018-03-13 at 16:35 +0800, Ming Lei wrote:
Then looks this issue need to fix by making possible CPU count
accurate
because there are other resources allocated according to
num_possible_cpus(),
such as percpu variables.
Short term the regression should be fixed. It is already v4.16-rc6, we
have little time left.
Right.
Longer term, yeah, I agree. Kernel's notion of possible CPU count
should be realistic.
I did a patch for that, Artem, could you help me to test it.
I didn't consider the nr_cpu_ids before. please ignore the old patch and
try the following RFC patch.
Thanks
dou
--------------------------->8-------------------------------------
diff --git a/drivers/acpi/acpi_processor.c b/drivers/acpi/acpi_processor.c
index 449d86d39965..96d568408515 100644
--- a/drivers/acpi/acpi_processor.c
+++ b/drivers/acpi/acpi_processor.c
@@ -671,6 +671,23 @@ static acpi_status __init
acpi_processor_ids_walk(acpi_handle handle,
}
+static void __init acpi_refill_possible_map(void)
+{
+ unsigned int cpu, nr = 0;
+
+ if (nr_cpu_ids <= nr_unique_ids)
+ return;
+
+ for_each_possible_cpu(cpu) {
+ if (nr >= nr_unique_ids)
+ set_cpu_possible(cpu, false);
+ nr++;
+ }
+
+ nr_cpu_ids = nr_unique_ids;
+ pr_info("Allowing %d possible CPUs\n", nr_cpu_ids);
+}
+
static void __init acpi_processor_check_duplicates(void)
{
/* check the correctness for all processors in ACPI namespace */
@@ -680,6 +697,9 @@ static void __init acpi_processor_check_duplicates(void)
NULL, NULL, NULL);
acpi_get_devices(ACPI_PROCESSOR_DEVICE_HID,
acpi_processor_ids_walk,
NULL, NULL);
+
+ /* make possible CPU count more realistic */
+ acpi_refill_possible_map();
}
bool acpi_duplicate_processor_id(int proc_id)
