Hi Thomas,
At 05/23/2017 09:29 AM, Dou Liyang wrote:
Dear Thomas,
At 05/23/2017 04:23 AM, Thomas Gleixner wrote:
Dou,
On Wed, 10 May 2017, Dou Liyang wrote:
According to Ingo's and Eric's advice[1,2], Try my best to optimize the
init of interrupt delivery mode for x86.
sorry for replying late. The patchset is not forgotten, it's on my todo
list and I'll tend to it latest next week.
I am very glad to hear that. :)
I will check it again and wait for your advice.
I have come to a code bottleneck. Hope to spend your precious time and
let me move on.
Following is some test results for that patchset.
In a theoretical code analysis, the patchset can wrap the original
logic.
1) The original logic of the interrupt delivery mode setup：
-Step O_1) Keep in PIC mode or virtual wire mode:
Check (smp_found_config || !boot_cpu_has(X86_FEATURE_APIC))
true: PIC mode
false: virtual wire mode
-Step O_2) Try to switch to symmetric IO mode:
O_2_1) In up system:
-Check disable_apic
ture: *O_S_1* (original situation 1)
-Check whether there is a separate or integrated chip
don't has: *O_S_2*
-Check !smp_found_config
ture: *O_S_3*
-Others:
*O_S_4*
O_2_2) In smp-capable system:
-Check !smp_found_config && !acpi_lapic
true: goto *O_2_1)*
-Check if it is LAPIC
don't has: *O_S_5*
-Check !max_cpus
true: *O_S_6*
-read_apic_id() != boot_cpu_physical_apicid
true: *O_S_7*
-Others:
*O_S_8*
2) After that patchset, the new logic:
-Step N_1) Skip step O_1 and try to switch to the final interrupt mode
-Check disable_apic
ture: *N_S_1* (New situation 1)
-Check whether there is a separate or integrated chip
ture: *N_S_2*
-Check if (!smp_found_config)
ture: *N_S_3*
-Check !setup_max_cpus
ture: *N_S_4*
-Check read_apic_id() != boot_cpu_physical_apicid
ture: *N_S_5*
-Others:
*N_S_6*
O_S_1 is covered in N_S_1
O_S_2 is covered in N_S_2
O_S_3 is covered in N_S_3
O_S_4 is covered in N_S_6
O_S_5 is covered in N_S_2
O_S_6 is covered in N_S_4
O_S_7 is covered in N_S_5
O_S_8 is covered in N_S_6
--------------------------------------------
In the actual test, It also can work well in the situations of my test
matrix
The factors of test matrix:
X86 | SMP |LOCAL APIC|I/O APIC|UP_LATE_INIT|
----- |-----|----------|--------|------------|
32-bit| Y | Y | Y | Y |
64-bit| N | N | N | N |
disable_apic|X86_FEATURE_APIC|smp_found_config|
------------|----------------|----------------|
0 | 0 | 0 |
1 | 1 | 1 |
acpi_lapic|acpi_ioapic|setup_max_cpus|
----------|-----------|--------------|
0 | 0 | =0 |
1 | 1 | >0 |
Thanks,
Liyang.
Thanks,
tglx
