diff options
| author | Nicolas Pitre <nico@cam.org> | 2008-04-24 09:31:46 +0400 |
|---|---|---|
| committer | Lennert Buytenhek <buytenh@marvell.com> | 2008-06-23 00:44:36 +0400 |
| commit | f76e9154736e9ab47b64940d0062f19c80225b7f (patch) | |
| tree | eb8a909667362fc552894d7987ff3e57ade4fa0f | |
| parent | b0bfcce930bca38af056662e598991cb393eaa4a (diff) | |
| download | linux-f76e9154736e9ab47b64940d0062f19c80225b7f.tar.xz | |
[ARM] latencytop support
Available for !SMP only at the moment.
From Russell:
|Basically, if a thread is running on a CPU, thread_saved_fp() is invalid.
|So, the question is: what guarantees do we have here that 'tsk' is not
|running on another CPU?
Signed-off-by: Nicolas Pitre <nico@marvell.com>
Tested-by: Lennert Buytenhek <buytenh@marvell.com>
Signed-off-by: Lennert Buytenhek <buytenh@marvell.com>
| -rw-r--r-- | arch/arm/Kconfig | 5 | ||||
| -rw-r--r-- | arch/arm/kernel/stacktrace.c | 34 |
2 files changed, 35 insertions, 4 deletions
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index b786e68914d4..a91b9ac9a0e5 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -84,6 +84,11 @@ config STACKTRACE_SUPPORT bool default y +config HAVE_LATENCYTOP_SUPPORT + bool + depends on !SMP + default y + config LOCKDEP_SUPPORT bool default y diff --git a/arch/arm/kernel/stacktrace.c b/arch/arm/kernel/stacktrace.c index ae31deb2d065..90e0c35ae60d 100644 --- a/arch/arm/kernel/stacktrace.c +++ b/arch/arm/kernel/stacktrace.c @@ -36,6 +36,7 @@ EXPORT_SYMBOL(walk_stackframe); #ifdef CONFIG_STACKTRACE struct stack_trace_data { struct stack_trace *trace; + unsigned int no_sched_functions; unsigned int skip; }; @@ -43,27 +44,52 @@ static int save_trace(struct stackframe *frame, void *d) { struct stack_trace_data *data = d; struct stack_trace *trace = data->trace; + unsigned long addr = frame->lr; + if (data->no_sched_functions && in_sched_functions(addr)) + return 0; if (data->skip) { data->skip--; return 0; } - trace->entries[trace->nr_entries++] = frame->lr; + trace->entries[trace->nr_entries++] = addr; return trace->nr_entries >= trace->max_entries; } -void save_stack_trace(struct stack_trace *trace) +void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace) { struct stack_trace_data data; unsigned long fp, base; data.trace = trace; data.skip = trace->skip; - base = (unsigned long)task_stack_page(current); - asm("mov %0, fp" : "=r" (fp)); + base = (unsigned long)task_stack_page(tsk); + + if (tsk != current) { +#ifdef CONFIG_SMP + /* + * What guarantees do we have here that 'tsk' + * is not running on another CPU? + */ + BUG(); +#else + data.no_sched_functions = 1; + fp = thread_saved_fp(tsk); +#endif + } else { + data.no_sched_functions = 0; + asm("mov %0, fp" : "=r" (fp)); + } walk_stackframe(fp, base, base + THREAD_SIZE, save_trace, &data); + if (trace->nr_entries < trace->max_entries) + trace->entries[trace->nr_entries++] = ULONG_MAX; +} + +void save_stack_trace(struct stack_trace *trace) +{ + save_stack_trace_tsk(current, trace); } #endif |