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authorAndi Kleen <ak@suse.de>2006-09-26 10:52:28 +0200
committerAndi Kleen <andi@basil.nowhere.org>2006-09-26 10:52:28 +0200
commit0cb91a2293648507886563ccb91979cfc94d6a4b (patch)
treef2a994f8b874e3c81c5519d445a0c5fa5522e4b5
parentc16b63e09d9d03158e0a92e961234e94c4862620 (diff)
downloadop-kernel-dev-0cb91a2293648507886563ccb91979cfc94d6a4b.zip
op-kernel-dev-0cb91a2293648507886563ccb91979cfc94d6a4b.tar.gz
[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>
-rw-r--r--arch/i386/kernel/time.c23
-rw-r--r--include/asm-i386/ptrace.h4
-rw-r--r--kernel/spinlock.c5
3 files changed, 24 insertions, 8 deletions
diff --git a/arch/i386/kernel/time.c b/arch/i386/kernel/time.c
index edd00f6..5af802e 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 *)&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
diff --git a/include/asm-i386/ptrace.h b/include/asm-i386/ptrace.h
index f324c53..30a442e 100644
--- a/include/asm-i386/ptrace.h
+++ b/include/asm-i386/ptrace.h
@@ -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
diff --git a/kernel/spinlock.c b/kernel/spinlock.c
index fb524b0..9644a41 100644
--- a/kernel/spinlock.c
+++ b/kernel/spinlock.c
@@ -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>
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