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tracing: Use switch statement instead of ifs in set_tracer_flag()

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The "mask" passed in to set_trace_flag() has a single bit set. The
function then checks if the mask is equal to one of the option masks and
performs the appropriate function associated to that option.

Instead of having a bunch of "if ()" statement, use a "switch ()"
statement instead to make it cleaner and a bit more optimal.

No function changes.

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: https://patch.msgid.link/20251106003501.890298562@kernel.org
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
This commit is contained in:
Steven Rostedt
2025-11-05 19:33:26 -05:00
committed by Steven Rostedt (Google)
parent 9c5053083e
commit 3a0d5bc76f
1 changed files with 23 additions and 15 deletions
Download Patch File Download Diff File Expand all files Collapse all files

38
kernel/trace/trace.c
View File

@@ -5220,11 +5220,13 @@ int trace_keep_overwrite(struct tracer *tracer, u64 mask, int set)
int set_tracer_flag(struct trace_array *tr, u64 mask, int enabled)
{
if ((mask == TRACE_ITER(RECORD_TGID)) ||
(mask == TRACE_ITER(RECORD_CMD)) ||
(mask == TRACE_ITER(TRACE_PRINTK)) ||
(mask == TRACE_ITER(COPY_MARKER)))
switch (mask) {
case TRACE_ITER(RECORD_TGID):
case TRACE_ITER(RECORD_CMD):
case TRACE_ITER(TRACE_PRINTK):
case TRACE_ITER(COPY_MARKER):
lockdep_assert_held(&event_mutex);
}
/* do nothing if flag is already set */
if (!!(tr->trace_flags & mask) == !!enabled)
@@ -5235,7 +5237,8 @@ int set_tracer_flag(struct trace_array *tr, u64 mask, int enabled)
if (tr->current_trace->flag_changed(tr, mask, !!enabled))
return -EINVAL;
if (mask == TRACE_ITER(TRACE_PRINTK)) {
switch (mask) {
case TRACE_ITER(TRACE_PRINTK):
if (enabled) {
update_printk_trace(tr);
} else {
@@ -5252,9 +5255,9 @@ int set_tracer_flag(struct trace_array *tr, u64 mask, int enabled)
if (printk_trace == tr)
update_printk_trace(&global_trace);
}
}
break;
if (mask == TRACE_ITER(COPY_MARKER)) {
case TRACE_ITER(COPY_MARKER):
update_marker_trace(tr, enabled);
/* update_marker_trace updates the tr->trace_flags */
return 0;
@@ -5265,10 +5268,12 @@ int set_tracer_flag(struct trace_array *tr, u64 mask, int enabled)
else
tr->trace_flags &= ~mask;
if (mask == TRACE_ITER(RECORD_CMD))
switch (mask) {
case TRACE_ITER(RECORD_CMD):
trace_event_enable_cmd_record(enabled);
break;
if (mask == TRACE_ITER(RECORD_TGID)) {
case TRACE_ITER(RECORD_TGID):
if (trace_alloc_tgid_map() < 0) {
tr->trace_flags &= ~TRACE_ITER(RECORD_TGID);
@@ -5276,24 +5281,27 @@ int set_tracer_flag(struct trace_array *tr, u64 mask, int enabled)
}
trace_event_enable_tgid_record(enabled);
}
break;
if (mask == TRACE_ITER(EVENT_FORK))
case TRACE_ITER(EVENT_FORK):
trace_event_follow_fork(tr, enabled);
break;
if (mask == TRACE_ITER(FUNC_FORK))
case TRACE_ITER(FUNC_FORK):
ftrace_pid_follow_fork(tr, enabled);
break;
if (mask == TRACE_ITER(OVERWRITE)) {
case TRACE_ITER(OVERWRITE):
ring_buffer_change_overwrite(tr->array_buffer.buffer, enabled);
#ifdef CONFIG_TRACER_MAX_TRACE
ring_buffer_change_overwrite(tr->max_buffer.buffer, enabled);
#endif
}
break;
if (mask == TRACE_ITER(PRINTK)) {
case TRACE_ITER(PRINTK):
trace_printk_start_stop_comm(enabled);
trace_printk_control(enabled);
break;
}
return 0;