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Commit 0cb91a22 authored by Andi Kleen's avatar Andi Kleen Committed by Andi Kleen
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[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: default avatarAndi Kleen <ak@suse.de>
parent c16b63e0

arch/i386/kernel/time.c

+19 −4
Original line number Diff line number Diff line
@@ -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

include/asm-i386/ptrace.h

+0 −4
Original line number Diff line number Diff line
@@ -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

kernel/spinlock.c

+5 −0
Original line number Diff line number Diff line
@@ -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>