diff options
| author | Vojtech Pavlik <vojtech@suse.cz> | 2006-09-26 08:52:28 (GMT) |
|---|---|---|
| committer | Andi Kleen <andi@basil.nowhere.org> | 2006-09-26 08:52:28 (GMT) |
| commit | c08c820508233b424deab3302bc404bbecc6493a (patch) | |
| tree | d6ed79fb2d03513f6c71fc7e47705c4a19512f53 /arch/x86_64/kernel/time.c | |
| parent | a670fad0adb1cc6202a607d250f10bd380593905 (diff) | |
| download | linux-c08c820508233b424deab3302bc404bbecc6493a.tar.xz | |
[PATCH] Add the vgetcpu vsyscall
This patch adds a vgetcpu vsyscall, which depending on the CPU RDTSCP
capability uses either the RDTSCP or CPUID to obtain a CPU and node
numbers and pass them to the program.
AK: Lots of changes over Vojtech's original code:
Better prototype for vgetcpu()
It's better to pass the cpu / node numbers as separate arguments
to avoid mistakes when going from SMP to NUMA.
Also add a fast time stamp based cache using a user supplied
argument to speed things more up.
Use fast method from Chuck Ebbert to retrieve node/cpu from
GDT limit instead of CPUID
Made sure RDTSCP init is always executed after node is known.
Drop printk
Signed-off-by: Vojtech Pavlik <vojtech@suse.cz>
Signed-off-by: Andi Kleen <ak@suse.de>
Diffstat (limited to 'arch/x86_64/kernel/time.c')
| -rw-r--r-- | arch/x86_64/kernel/time.c | 13 |
1 files changed, 7 insertions, 6 deletions
diff --git a/arch/x86_64/kernel/time.c b/arch/x86_64/kernel/time.c index 97b9e46d..560ed94 100644 --- a/arch/x86_64/kernel/time.c +++ b/arch/x86_64/kernel/time.c @@ -899,12 +899,8 @@ static int __cpuinit time_cpu_notifier(struct notifier_block *nb, unsigned long action, void *hcpu) { unsigned cpu = (unsigned long) hcpu; - if (action == CPU_ONLINE && - cpu_has(&cpu_data[cpu], X86_FEATURE_RDTSCP)) { - unsigned p; - p = smp_processor_id() | (cpu_to_node(smp_processor_id())<<12); - write_rdtscp_aux(p); - } + if (action == CPU_ONLINE) + vsyscall_set_cpu(cpu); return NOTIFY_DONE; } @@ -993,6 +989,11 @@ void time_init_gtod(void) if (unsynchronized_tsc()) notsc = 1; + if (cpu_has(&boot_cpu_data, X86_FEATURE_RDTSCP)) + vgetcpu_mode = VGETCPU_RDTSCP; + else + vgetcpu_mode = VGETCPU_LSL; + if (vxtime.hpet_address && notsc) { timetype = hpet_use_timer ? "HPET" : "PIT/HPET"; if (hpet_use_timer) |