atrace: Set saved_cmdline_size to 8192

This increases the size of the table tracking comms and pids and
prevents overwriting them easily.

Bug: 38167231

Change-Id: I69b9000e4f9d0c2c7969efd38e02d8c1bffdad5c
Signed-off-by: Joel Fernandes <joelaf@google.com>
(cherry picked from commit ed80bd04cc3bf80082b1d733ef06d90a29c6270a)
diff --git a/cmds/atrace/atrace.cpp b/cmds/atrace/atrace.cpp
index d3e0cd4..1a803f3 100644
--- a/cmds/atrace/atrace.cpp
+++ b/cmds/atrace/atrace.cpp
@@ -215,6 +215,9 @@
 static const char* k_traceBufferSizePath =
     "buffer_size_kb";
 
+static const char* k_traceCmdlineSizePath =
+    "saved_cmdlines_size";
+
 static const char* k_tracingOverwriteEnablePath =
     "options/overwrite";
 
@@ -437,6 +440,12 @@
     return writeStr(k_traceBufferSizePath, str);
 }
 
+// Set the default size of cmdline hashtable
+static bool setCmdlineSize()
+{
+    return writeStr(k_traceCmdlineSizePath, "8192");
+}
+
 // Set the clock to the best available option while tracing. Use 'boot' if it's
 // available; otherwise, use 'mono'. If neither are available use 'global'.
 // Any write to the trace_clock sysfs file will reset the buffer, so only
@@ -757,6 +766,7 @@
     ok &= setCategoriesEnableFromFile(g_categoriesFile);
     ok &= setTraceOverwriteEnable(g_traceOverwrite);
     ok &= setTraceBufferSizeKB(g_traceBufferSizeKB);
+    ok &= setCmdlineSize();
     ok &= setClock();
     ok &= setPrintTgidEnableIfPresent(true);
     ok &= setKernelTraceFuncs(g_kernelTraceFuncs);