From: "Steven Rostedt (Red Hat)" <[email protected]> The function __buffer_unlock_commit() is called in a few places outside of trace.c. But for the most part, it should really be inlined, as it is in the hot path of the trace_events. For the callers outside of trace.c, create a new function trace_buffer_unlock_commit_nostack(), as the reason it was used was to avoid the stack tracing that trace_buffer_unlock_commit() could do.
Link: http://lkml.kernel.org/r/[email protected] Reported-by: Andi Kleen <[email protected]> Signed-off-by: Steven Rostedt <[email protected]> --- kernel/trace/trace.c | 41 +++++++++++++++++++++++------------- kernel/trace/trace.h | 4 ++-- kernel/trace/trace_branch.c | 2 +- kernel/trace/trace_functions_graph.c | 4 ++-- kernel/trace/trace_hwlat.c | 2 +- 5 files changed, 32 insertions(+), 21 deletions(-) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 725e8b2c453f..60416bf7c591 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -794,6 +794,22 @@ void tracing_on(void) } EXPORT_SYMBOL_GPL(tracing_on); + +static __always_inline void +__buffer_unlock_commit(struct ring_buffer *buffer, struct ring_buffer_event *event) +{ + __this_cpu_write(trace_cmdline_save, true); + + /* If this is the temp buffer, we need to commit fully */ + if (this_cpu_read(trace_buffered_event) == event) { + /* Length is in event->array[0] */ + ring_buffer_write(buffer, event->array[0], &event->array[1]); + /* Release the temp buffer */ + this_cpu_dec(trace_buffered_event_cnt); + } else + ring_buffer_unlock_commit(buffer, event); +} + /** * __trace_puts - write a constant string into the trace buffer. * @ip: The address of the caller @@ -2059,21 +2075,6 @@ void trace_buffered_event_disable(void) preempt_enable(); } -void -__buffer_unlock_commit(struct ring_buffer *buffer, struct ring_buffer_event *event) -{ - __this_cpu_write(trace_cmdline_save, true); - - /* If this is the temp buffer, we need to commit fully */ - if (this_cpu_read(trace_buffered_event) == event) { - /* Length is in event->array[0] */ - ring_buffer_write(buffer, event->array[0], &event->array[1]); - /* Release the temp buffer */ - this_cpu_dec(trace_buffered_event_cnt); - } else - ring_buffer_unlock_commit(buffer, event); -} - static struct ring_buffer *temp_buffer; struct ring_buffer_event * @@ -2214,6 +2215,16 @@ void trace_buffer_unlock_commit_regs(struct trace_array *tr, ftrace_trace_userstack(buffer, flags, pc); } +/* + * Similar to trace_buffer_unlock_commit_regs() but do not dump stack. + */ +void +trace_buffer_unlock_commit_nostack(struct ring_buffer *buffer, + struct ring_buffer_event *event) +{ + __buffer_unlock_commit(buffer, event); +} + static void trace_process_export(struct trace_export *export, struct ring_buffer_event *event) diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 9294f8606ade..37602e722336 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -602,8 +602,8 @@ struct trace_entry *tracing_get_trace_entry(struct trace_array *tr, struct trace_entry *trace_find_next_entry(struct trace_iterator *iter, int *ent_cpu, u64 *ent_ts); -void __buffer_unlock_commit(struct ring_buffer *buffer, - struct ring_buffer_event *event); +void trace_buffer_unlock_commit_nostack(struct ring_buffer *buffer, + struct ring_buffer_event *event); int trace_empty(struct trace_iterator *iter); diff --git a/kernel/trace/trace_branch.c b/kernel/trace/trace_branch.c index 3a2a73716a5b..75489de546b6 100644 --- a/kernel/trace/trace_branch.c +++ b/kernel/trace/trace_branch.c @@ -81,7 +81,7 @@ probe_likely_condition(struct ftrace_branch_data *f, int val, int expect) entry->correct = val == expect; if (!call_filter_check_discard(call, entry, buffer, event)) - __buffer_unlock_commit(buffer, event); + trace_buffer_unlock_commit_nostack(buffer, event); out: current->trace_recursion &= ~TRACE_BRANCH_BIT; diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c index 4e480e870474..8e1a115439fa 100644 --- a/kernel/trace/trace_functions_graph.c +++ b/kernel/trace/trace_functions_graph.c @@ -358,7 +358,7 @@ int __trace_graph_entry(struct trace_array *tr, entry = ring_buffer_event_data(event); entry->graph_ent = *trace; if (!call_filter_check_discard(call, entry, buffer, event)) - __buffer_unlock_commit(buffer, event); + trace_buffer_unlock_commit_nostack(buffer, event); return 1; } @@ -469,7 +469,7 @@ void __trace_graph_return(struct trace_array *tr, entry = ring_buffer_event_data(event); entry->ret = *trace; if (!call_filter_check_discard(call, entry, buffer, event)) - __buffer_unlock_commit(buffer, event); + trace_buffer_unlock_commit_nostack(buffer, event); } void trace_graph_return(struct ftrace_graph_ret *trace) diff --git a/kernel/trace/trace_hwlat.c b/kernel/trace/trace_hwlat.c index b97286c48735..775569ec50d0 100644 --- a/kernel/trace/trace_hwlat.c +++ b/kernel/trace/trace_hwlat.c @@ -127,7 +127,7 @@ static void trace_hwlat_sample(struct hwlat_sample *sample) entry->nmi_count = sample->nmi_count; if (!call_filter_check_discard(call, entry, buffer, event)) - __buffer_unlock_commit(buffer, event); + trace_buffer_unlock_commit_nostack(buffer, event); } /* Macros to encapsulate the time capturing infrastructure */ -- 2.10.2
