stack: Initialize -n maxframes to 256 by default.

Make -n default just 256 frames, 2048 was too big. Also Document magic
number used in frames.allocated initialization.

Signed-off-by: Mark Wielaard <mjw@redhat.com>

diff --git a/src/ChangeLog b/src/ChangeLog
index 143d73ccb40da70a04fb1a268bbbd3570567c00b..d1b221f20c74eeecd35e9fb58b74928b4bbe8bee 100644 (file)
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,9 @@
+2014-01-27  Mark Wielaard  <mjw@redhat.com>
+
+       * stack.c (maxframes): Initialize to 256.
+       (main): Document new default in options. Document magic number
+       used in frames.allocated initialization.
+
 2014-01-20  Mark Wielaard  <mjw@redhat.com>
 
        * stack.c (show_debugname): New static boolean.

diff --git a/src/stack.c b/src/stack.c
index ae0ef126513a6f887c83871ad923ff8a4fddd7b1..e675267dd2c0c5737deeebf7910f056490ed793d 100644 (file)
--- a/src/stack.c
+++ b/src/stack.c
@@ -52,7 +52,7 @@ static bool show_raw = false;
 static bool show_modules = false;
 static bool show_debugname = false;
 
-static int maxframes = 2048;
+static int maxframes = 256;
 
 struct frame
 {
@@ -571,7 +571,7 @@ main (int argc, char **argv)
       { NULL, '1', NULL, 0,
        N_("Show the backtrace of only one thread"), 0 },
       { NULL, 'n', "MAXFRAMES", 0,
-       N_("Show at most MAXFRAMES per thread (default 2048, use 0 for unlimited)"), 0 },
+       N_("Show at most MAXFRAMES per thread (default 256, use 0 for unlimited)"), 0 },
       { "list-modules", 'l', NULL, 0,
        N_("Show module memory map with build-id, elf and debug files detected"), 0 },
       { NULL, 0, NULL, 0, NULL, 0 }
@@ -601,6 +601,8 @@ invoked with bad or missing arguments it will exit with return code 64.")
     }
 
   struct frames frames;
+  /* When maxframes is zero, then 2048 is just the initial allocation
+     that will be increased using realloc in framecallback ().  */
   frames.allocated = maxframes == 0 ? 2048 : maxframes;
   frames.frames = 0;
   frames.frame = malloc (sizeof (struct frame) * frames.allocated);