Messages in this thread | | | Date | Sun, 21 Dec 2008 11:00:47 +0100 | From | Ingo Molnar <> | Subject | Re: [PATCH v2] tracing/function-graph-tracer: prevent from hrtimer interrupt infinite loop |
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btw., a graph-tracer buglet i noticed:
3) | perf_counter_task_tick() { 3) | perf_counter_task_sched_out() { 3) | /* c:ffff88049b184000, u:0: 0000000020ca1ab0 + 0000000000000000 = 0000000020ca1ab0 */ 3) | /* sched-out counter ffff88049b184000, state: 0 */ 3) 5.024 us | } 3) | perf_counter_task_sched_in() { 3) | /* c:ffff88049b184000, u:0: 0000000020ca1ab0 + 0000000000000000 = 0000000020ca1ab0 */ 3) | /* sched-in counter ffff88049b184000, state: 1 */ 3) 2.605 us | } 3) 9.714 us | } 3) | perf_counter_task_tick() {
the bug is that the '*/' comment closing text is printed in the next line - that's not a linewrap, it happened like this in the trace.
The reason is that the ftrace_printk did:
ftrace_printk("c:%p, u:%d: %016Lx + %016Lx = %016Lx\n",
the closing \n is pretty natural - especially for kernel hackers who might just turn printk()s into ftrace_printk(), to embedd printouts in function traces. So it would be nice if ftrace skipped over \n's when printing them out as embedded C comments.
Ingo
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