Messages in this thread Patch in this message | | | Subject | Re: [PATCH V3 0/4] genirq/affinity: irq vector spread among online CPUs as far as possible | From | Dou Liyang <> | Date | Wed, 14 Mar 2018 12:11:26 +0800 |
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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@gmail.com> 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
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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)
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