linux/arch/x86/include/asm/stacktrace.h
Frederic Weisbecker 06d65bda75 perf events, x86/stacktrace: Fix performance/softlockup by providing a special frame pointer-only stack walker
It's just wasteful for stacktrace users like perf to walk
through every entries on the stack whereas these only accept
reliable ones, ie: that the frame pointer validates.

Since perf requires pure reliable stacktraces, it needs a stack
walker based on frame pointers-only to optimize the stacktrace
processing.

This might solve some near-lockup scenarios that can be triggered
by call-graph tracing timer events.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <1261024834-5336-2-git-send-regression-fweisbec@gmail.com>
[ v2: fix for modular builds and small detail tidyup ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-17 10:42:52 +01:00

48 lines
1.4 KiB
C

#ifndef _ASM_X86_STACKTRACE_H
#define _ASM_X86_STACKTRACE_H
extern int kstack_depth_to_print;
int x86_is_stack_id(int id, char *name);
struct thread_info;
struct stacktrace_ops;
typedef unsigned long (*walk_stack_t)(struct thread_info *tinfo,
unsigned long *stack,
unsigned long bp,
const struct stacktrace_ops *ops,
void *data,
unsigned long *end,
int *graph);
extern unsigned long
print_context_stack(struct thread_info *tinfo,
unsigned long *stack, unsigned long bp,
const struct stacktrace_ops *ops, void *data,
unsigned long *end, int *graph);
extern unsigned long
print_context_stack_bp(struct thread_info *tinfo,
unsigned long *stack, unsigned long bp,
const struct stacktrace_ops *ops, void *data,
unsigned long *end, int *graph);
/* Generic stack tracer with callbacks */
struct stacktrace_ops {
void (*warning)(void *data, char *msg);
/* msg must contain %s for the symbol */
void (*warning_symbol)(void *data, char *msg, unsigned long symbol);
void (*address)(void *data, unsigned long address, int reliable);
/* On negative return stop dumping */
int (*stack)(void *data, char *name);
walk_stack_t walk_stack;
};
void dump_trace(struct task_struct *tsk, struct pt_regs *regs,
unsigned long *stack, unsigned long bp,
const struct stacktrace_ops *ops, void *data);
#endif /* _ASM_X86_STACKTRACE_H */