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8234512: Missing pieces from JDK-8224816

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Reviewed-by: rehn, pliden, kbarrett, gziemski
This commit is contained in:
Erik Österlund 2019-11-20 14:51:42 +00:00
parent b10495d436
commit 8e709f03bb
1 changed files with 19 additions and 13 deletions

32
src/hotspot/os/bsd/os_bsd.cpp

@ -3205,14 +3205,14 @@ int os::active_processor_count() {
}
#ifdef __APPLE__
uint os::processor_id() {
static volatile int* volatile apic_to_cpu_mapping = NULL;
static volatile int next_cpu_id = 0;
static volatile int* volatile apic_to_processor_mapping = NULL;
static volatile int next_processor_id = 0;
volatile int* mapping = OrderAccess::load_acquire(&apic_to_cpu_mapping);
static inline volatile int* get_apic_to_processor_mapping() {
volatile int* mapping = OrderAccess::load_acquire(&apic_to_processor_mapping);
if (mapping == NULL) {
// Calculate possible number space for APIC ids. This space is not necessarily
// in the range [0, number_of_cpus).
// in the range [0, number_of_processors).
uint total_bits = 0;
for (uint i = 0;; ++i) {
uint eax = 0xb; // Query topology leaf
@ -3238,33 +3238,39 @@ uint os::processor_id() {
mapping[i] = -1;
}
if (!Atomic::replace_if_null(mapping, &apic_to_cpu_mapping)) {
if (!Atomic::replace_if_null(mapping, &apic_to_processor_mapping)) {
FREE_C_HEAP_ARRAY(int, mapping);
mapping = OrderAccess::load_acquire(&apic_to_cpu_mapping);
mapping = OrderAccess::load_acquire(&apic_to_processor_mapping);
}
}
return mapping;
}
uint os::processor_id() {
volatile int* mapping = get_apic_to_processor_mapping();
uint eax = 0xb;
uint ebx;
uint ecx = 0;
uint edx;
asm ("cpuid\n\t" : "+a" (eax), "+b" (ebx), "+c" (ecx), "+d" (edx) : );
__asm__ ("cpuid\n\t" : "+a" (eax), "+b" (ebx), "+c" (ecx), "+d" (edx) : );
// Map from APIC id to a unique logical processor ID in the expected
// [0, num_processors) range.
uint apic_id = edx;
int cpu_id = Atomic::load(&mapping[apic_id]);
int processor_id = Atomic::load(&mapping[apic_id]);
while (cpu_id < 0) {
while (processor_id < 0) {
if (Atomic::cmpxchg(-2, &mapping[apic_id], -1)) {
Atomic::store(Atomic::add(1, &next_cpu_id) - 1, &mapping[apic_id]);
Atomic::store(Atomic::add(1, &next_processor_id) - 1, &mapping[apic_id]);
}
cpu_id = Atomic::load(&mapping[apic_id]);
processor_id = Atomic::load(&mapping[apic_id]);
}
return (uint)cpu_id;
return (uint)processor_id;
}
#endif