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| author | Vojtech Pavlik <vojtech@suse.cz> | 2006-09-26 10:52:28 +0200 |
|---|---|---|
| committer | Andi Kleen <andi@basil.nowhere.org> | 2006-09-26 10:52:28 +0200 |
| commit | c08c820508233b424deab3302bc404bbecc6493a (patch) | |
| tree | d6ed79fb2d03513f6c71fc7e47705c4a19512f53 /include/asm-x86_64/segment.h | |
| parent | a670fad0adb1cc6202a607d250f10bd380593905 (diff) | |
| download | lwn-c08c820508233b424deab3302bc404bbecc6493a.tar.gz lwn-c08c820508233b424deab3302bc404bbecc6493a.zip | |
[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 'include/asm-x86_64/segment.h')
| -rw-r--r-- | include/asm-x86_64/segment.h | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/include/asm-x86_64/segment.h b/include/asm-x86_64/segment.h index d4bed33fb32c..334ddcdd8f92 100644 --- a/include/asm-x86_64/segment.h +++ b/include/asm-x86_64/segment.h @@ -20,15 +20,16 @@ #define __USER_CS 0x33 /* 6*8+3 */ #define __USER32_DS __USER_DS -#define GDT_ENTRY_TLS 1 #define GDT_ENTRY_TSS 8 /* needs two entries */ #define GDT_ENTRY_LDT 10 /* needs two entries */ #define GDT_ENTRY_TLS_MIN 12 #define GDT_ENTRY_TLS_MAX 14 -/* 15 free */ #define GDT_ENTRY_TLS_ENTRIES 3 +#define GDT_ENTRY_PER_CPU 15 /* Abused to load per CPU data from limit */ +#define __PER_CPU_SEG (GDT_ENTRY_PER_CPU * 8 + 3) + /* TLS indexes for 64bit - hardcoded in arch_prctl */ #define FS_TLS 0 #define GS_TLS 1 |