On Wed, Feb 12, 2014 at 07:40:36AM -0500, Steven Rostedt wrote: > The pt_regs structure. > > That's what? 21 unsigned longs? 21 * 8 = 168. I think that's the > culprit here. > > Peter and Frederic, is there a way not to store that on the stack? Something like so? --- include/trace/ftrace.h | 7 ++++--- kernel/trace/trace_event_perf.c | 5 ++++- 2 files changed, 8 insertions(+), 4 deletions(-) diff --git a/include/trace/ftrace.h b/include/trace/ftrace.h index 1a8b28db3775..87ae3ef1d278 100644 --- a/include/trace/ftrace.h +++ b/include/trace/ftrace.h @@ -678,7 +678,7 @@ perf_trace_##call(void *__data, proto) \ struct ftrace_event_call *event_call = __data; \ struct ftrace_data_offsets_##call __maybe_unused __data_offsets;\ struct ftrace_raw_##call *entry; \ - struct pt_regs __regs; \ + struct pt_regs *__regs; \ u64 __addr = 0, __count = 1; \ struct task_struct *__task = NULL; \ struct hlist_head *head; \ @@ -697,18 +697,19 @@ perf_trace_##call(void *__data, proto) \ sizeof(u64)); \ __entry_size -= sizeof(u32); \ \ - perf_fetch_caller_regs(&__regs); \ entry = perf_trace_buf_prepare(__entry_size, \ event_call->event.type, &__regs, &rctx); \ if (!entry) \ return; \ \ + perf_fetch_caller_regs(__regs); \ + \ tstruct \ \ { assign; } \ \ perf_trace_buf_submit(entry, __entry_size, rctx, __addr, \ - __count, &__regs, head, __task); \ + __count, __regs, head, __task); \ } /* diff --git a/kernel/trace/trace_event_perf.c b/kernel/trace/trace_event_perf.c index e854f420e033..1885f4aac109 100644 --- a/kernel/trace/trace_event_perf.c +++ b/kernel/trace/trace_event_perf.c @@ -232,8 +232,10 @@ void perf_trace_del(struct perf_event *p_event, int flags) tp_event->class->reg(tp_event, TRACE_REG_PERF_DEL, p_event); } +static DEFINE_PER_CPU(struct pt_regs, tp_regs[4]); + __kprobes void *perf_trace_buf_prepare(int size, unsigned short type, - struct pt_regs *regs, int *rctxp) + struct pt_regs **regs, int *rctxp) { struct trace_entry *entry; unsigned long flags; @@ -252,6 +254,7 @@ __kprobes void *perf_trace_buf_prepare(int size, unsigned short type, if (*rctxp < 0) return NULL; + *regs = this_cpu_ptr(&tp_regs[*rctxp]); raw_data = this_cpu_ptr(perf_trace_buf[*rctxp]); /* zero the dead bytes from align to not leak stack to user */ _______________________________________________ xfs mailing list xfs@xxxxxxxxxxx http://oss.sgi.com/mailman/listinfo/xfs