[PATCH v4 2/6] trace-cmd library: Track maximum CPUs count in input handler

["Tzvetomir Stoyanov (VMware)" <tz.stoyanov@gmail.com>]

This clean up is needed for the design of the next trace file version,
where only CPUs with trace data could be stored in the file. Each trace
instance may have its own CPU count, depending on collected traces.
As the main input handler is used by the top trace instance, the
CPU count there is for the top trace instance and may differ with cpu
counts of the other instances. Added a new "max_cpu" member of the input
handler, that tracks the maximum CPU count of all instances, recorded in
the file.

Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
---
 lib/trace-cmd/trace-input.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/lib/trace-cmd/trace-input.c b/lib/trace-cmd/trace-input.c
index b4af783b..aaafe3a4 100644
--- a/lib/trace-cmd/trace-input.c
+++ b/lib/trace-cmd/trace-input.c
@@ -125,6 +125,7 @@ struct tracecmd_input {
 	int			long_size;
 	int			page_size;
 	int			page_map_size;
+	int			max_cpu;
 	int			cpus;
 	int			ref;
 	int			nr_buffers;	/* buffer instances */
@@ -826,6 +827,7 @@ static int read_cpus(struct tracecmd_input *handle)
 		return -1;
 
 	handle->cpus = cpus;
+	handle->max_cpu = cpus;
 	tep_set_cpus(handle->pevent, handle->cpus);
 	handle->file_state = TRACECMD_FILE_CPU_COUNT;
 
@@ -2780,6 +2782,9 @@ static int handle_options(struct tracecmd_input *handle)
 		case TRACECMD_OPTION_CPUCOUNT:
 			cpus = *(int *)buf;
 			handle->cpus = tep_read_number(handle->pevent, &cpus, 4);
+			if (handle->cpus > handle->max_cpu)
+				handle->max_cpu = handle->cpus;
+			tep_set_cpus(handle->pevent, handle->cpus);
 			break;
 		case TRACECMD_OPTION_PROCMAPS:
 			if (buf[size-1] == '\0')
@@ -4054,7 +4059,7 @@ int tracecmd_page_size(struct tracecmd_input *handle)
  */
 int tracecmd_cpus(struct tracecmd_input *handle)
 {
-	return handle->cpus;
+	return handle->max_cpu;
 }
 
 /**
-- 
2.31.1