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| author | Andi Kleen <ak@suse.de> | 2006-09-26 10:52:28 +0200 |
|---|---|---|
| committer | Andi Kleen <andi@basil.nowhere.org> | 2006-09-26 10:52:28 +0200 |
| commit | 0cb91a2293648507886563ccb91979cfc94d6a4b (patch) | |
| tree | f2a994f8b874e3c81c5519d445a0c5fa5522e4b5 /arch/i386/kernel/time.c | |
| parent | c16b63e09d9d03158e0a92e961234e94c4862620 (diff) | |
| download | lwn-0cb91a2293648507886563ccb91979cfc94d6a4b.tar.gz lwn-0cb91a2293648507886563ccb91979cfc94d6a4b.zip | |
[PATCH] i386: Account spinlocks to the caller during profiling for !FP kernels
This ports the algorithm from x86-64 (with improvements) to i386.
Previously this only worked for frame pointer enabled kernels.
But spinlocks have a very simple stack frame that can be manually
analyzed. Do this.
Signed-off-by: Andi Kleen <ak@suse.de>
Diffstat (limited to 'arch/i386/kernel/time.c')
| -rw-r--r-- | arch/i386/kernel/time.c | 23 |
1 files changed, 19 insertions, 4 deletions
diff --git a/arch/i386/kernel/time.c b/arch/i386/kernel/time.c index edd00f6cee37..5af802ef00b2 100644 --- a/arch/i386/kernel/time.c +++ b/arch/i386/kernel/time.c @@ -130,18 +130,33 @@ static int set_rtc_mmss(unsigned long nowtime) int timer_ack; -#if defined(CONFIG_SMP) && defined(CONFIG_FRAME_POINTER) unsigned long profile_pc(struct pt_regs *regs) { unsigned long pc = instruction_pointer(regs); - if (!user_mode_vm(regs) && in_lock_functions(pc)) +#ifdef CONFIG_SMP + if (!user_mode_vm(regs) && in_lock_functions(pc)) { +#ifdef CONFIG_FRAME_POINTER return *(unsigned long *)(regs->ebp + 4); - +#else + unsigned long *sp; + if ((regs->xcs & 3) == 0) + sp = (unsigned long *)®s->esp; + else + sp = (unsigned long *)regs->esp; + /* Return address is either directly at stack pointer + or above a saved eflags. Eflags has bits 22-31 zero, + kernel addresses don't. */ + if (sp[0] >> 22) + return sp[0]; + if (sp[1] >> 22) + return sp[1]; +#endif + } +#endif return pc; } EXPORT_SYMBOL(profile_pc); -#endif /* * This is the same as the above, except we _also_ save the current |