main(): add a TODO about finding a use for _end[] area

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

diff --git a/libbb/appletlib.c b/libbb/appletlib.c
index 4b5b09f45db6e20fabe3b5593c072ff9047c83d9..d798a2eacc1e139888a8a9334e1e30dec02bd111 100644 (file)
--- a/libbb/appletlib.c
+++ b/libbb/appletlib.c
@@ -902,6 +902,19 @@ int lbb_main(char **argv)
 int main(int argc UNUSED_PARAM, char **argv)
 #endif
 {
+#if 0
+       /* TODO: find a use for a block of memory between end of .bss
+        * and end of page. For example, I'm getting "_end:0x812e698 2408 bytes"
+        * - more than 2k of wasted memory (in this particular build)
+        * *per each running process*!
+        * (If your linker does not generate "_end" name, weak attribute
+        * makes &_end == NULL, end_len == 0 here.)
+        */
+       extern char _end[] __attribute__((weak));
+       unsigned end_len = (-(int)_end) & 0xfff;
+       printf("_end:%p %u bytes\n", &_end, end_len);
+#endif
+
        /* Tweak malloc for reduced memory consumption */
 #ifdef M_TRIM_THRESHOLD
        /* M_TRIM_THRESHOLD is the maximum amount of freed top-most memory