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[PATCH] i386: Account spinlocks to the caller during profiling for !FP kernels

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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>
This commit is contained in:
Andi Kleen 2006-09-26 10:52:28 +02:00 committed by Andi Kleen
parent c16b63e09d
commit 0cb91a2293
3 changed files with 24 additions and 8 deletions
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23
arch/i386/kernel/time.c
View File

@ -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 *)&regs->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

4
include/asm-i386/ptrace.h
View File

@ -80,11 +80,7 @@ static inline int user_mode_vm(struct pt_regs *regs)
return ((regs->xcs & 3) | (regs->eflags & VM_MASK)) != 0;
}
#define instruction_pointer(regs) ((regs)->eip)
#if defined(CONFIG_SMP) && defined(CONFIG_FRAME_POINTER)
extern unsigned long profile_pc(struct pt_regs *regs);
#else
#define profile_pc(regs) instruction_pointer(regs)
#endif
#endif /* __KERNEL__ */
#endif

5
kernel/spinlock.c
View File

@ -7,6 +7,11 @@
*
* This file contains the spinlock/rwlock implementations for the
* SMP and the DEBUG_SPINLOCK cases. (UP-nondebug inlines them)
*
* Note that some architectures have special knowledge about the
* stack frames of these functions in their profile_pc. If you
* change anything significant here that could change the stack
* frame contact the architecture maintainers.
*/
#include <linux/linkage.h>