From 34596dc9e59d7bece16fe5aba08116b49465da26 Mon Sep 17 00:00:00 2001 From: Andi Kleen Date: Sat, 30 Sep 2006 01:47:55 +0200 Subject: [PATCH] Define vsyscall cache as blob to make clearer that user space shouldn't use it Signed-off-by: Andi Kleen --- include/linux/getcpu.h | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) (limited to 'include/linux/getcpu.h') diff --git a/include/linux/getcpu.h b/include/linux/getcpu.h index 031ed37..c7372d7 100644 --- a/include/linux/getcpu.h +++ b/include/linux/getcpu.h @@ -1,16 +1,18 @@ #ifndef _LINUX_GETCPU_H #define _LINUX_GETCPU_H 1 -/* Cache for getcpu() to speed it up. Results might be upto a jiffie +/* Cache for getcpu() to speed it up. Results might be a short time out of date, but will be faster. + User programs should not refer to the contents of this structure. - It is only a cache for vgetcpu(). It might change in future kernels. + I repeat they should not refer to it. If they do they will break + in future kernels. + + It is only a private cache for vgetcpu(). It will change in future kernels. The user program must store this information per thread (__thread) If you want 100% accurate information pass NULL instead. */ struct getcpu_cache { - unsigned long t0; - unsigned long t1; - unsigned long res[4]; + unsigned long blob[128 / sizeof(long)]; }; #endif -- cgit v1.1