Re: [PATCH v2] tracing/function-graph-tracer: prevent from hrtimerinterrupt infinite loop

From: Ingo Molnar
Date: Sun Dec 21 2008 - 05:13:01 EST



* Ingo Molnar <mingo@xxxxxxx> wrote:

> btw., a graph-tracer buglet i noticed:

another thing. I turned off all the options that come ahead of the 'meat'
of the trace data:

# cat /debug/tracing/trace_options
print-parent nosym-offset nosym-addr noverbose noraw nohex nobin noblock
nostacktrace nosched-tree ftrace_printk noftrace_preempt nobranch annotate
nouserstacktrace nosym-userobj printk-msg-only nofuncgraph-overrun
nofuncgraph-cpu nofuncgraph-overhead nofuncgraph-proc

but i still got the 'duration' field printed:

# tracer: function_graph
#
# DURATION FUNCTION CALLS
# | | | | |

0.865 us | }
| alloc_page_vma() {
0.295 us | get_vma_policy();
0.268 us | policy_zonelist();
| __alloc_pages_internal() {
0.257 us | __might_sleep();
| get_page_from_freelist() {


i'd have expected to only see the flow of execution as it happens.

Ingo
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