awreece

$ go build -v
$ go tool dist install -v
$ hg diff malloc.goc 
diff -r 4875dfefc730 src/pkg/runtime/malloc.goc
--- a/src/pkg/runtime/malloc.goc	Mon Apr 16 10:25:20 2012 -0700
+++ b/src/pkg/runtime/malloc.goc	Mon Apr 30 19:52:32 2012 -0400
@@ -25,7 +25,7 @@
 // Small objects are allocated from the per-thread cache's free lists.
 // Large objects (> 32 kB) are allocated straight from the heap.
 void*

awreece

all: run_c run_go

.PHONY: run_c run_go

run_c : sleep_10_ms_c
	bash catproc.bash $<

run_go : sleep_10_ms_go
	bash catproc.bash $<

awreece

areece@areece-laptop:/tmp$ gdb temp
GNU gdb (Ubuntu/Linaro 7.3-0ubuntu2) 7.3-2011.08
Copyright (C) 2011 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.  Type "show copying"
and "show warranty" for details.
This GDB was configured as "i686-linux-gnu".
For bug reporting instructions, please see:

awreece

areece@areece-laptop:/tmp$ gdb temp
Reading symbols from /tmp/temp...done.
Loading Go Runtime support.
(gdb) b main.main
Breakpoint 1 at 0x8048c00: file /tmp/temp.go, line 2.
(gdb) r
Starting program: /tmp/temp 
[New LWP 6919]
[Switching to LWP 6919]

awreece

        assert(sizeof(uintptr_t) == 8);
        assert(sizeof(unsigned long long) == 8);
        uintptr_t x = 0xffffffff80000000ULL;
        x ^= (1 << 31);
        printf("%llx\n", x);

awreece

$ ltrace -x malloc /usr/lib/firefox/firefox
WARNING: Couldn't find symbol "malloc" in file "/usr/lib/firefox/firefox"
--- SIGCHLD (Child exited) ---
+++ exited (status 0) +++

awreece

$ ./command-line-arguments.test --test.bench="Bench"
testing: warning: no tests to run
PASS
BenchmarkConcat	   50000	     46822 ns/op
BenchmarkJoin	  200000	      9121 ns/op
BenchmarkBuffer	  200000	     10764 ns/op

awreece

1336443958168278000 0] malloc 32 -> 0x1883bb40                                  
1336443958168298000 0] malloc 48 -> 0x18895e70                                  
1336443958168318000 0] malloc 64 -> 0x1883ecc0                                  
1336443958168340000 0] malloc 208 -> 0x189d0000                                 
1336443958168364000 4] free 0x1885fd20                                          
1336443958168379000 4] free 0x1885fd20                                          
1336443958168396000 4] malloc 96 -> 0x1885fd20                                  
1336443958168418000 0] free 0x18844d80                                          
1336443958168433000 0] free 0x18844d80                                          
1336443958168448000 0] malloc 128 -> 0x18844d80                                 

awreece

$ for t in build get main; do python parse.py $t.trace; done

# a trace of "go build file"
Malloc trace of 75809 mallocs over 5 cores
	Cache line shared 2266 (2.99%) times
	Cache line cold missed 12022 (15.86%) times

# a trace of "go get package"
Malloc trace of 163991 mallocs over 4 cores
	Cache line shared 7507 (4.58%) times

awreece

$ cat *.trace | ./parse | sort -n
# allocation_size number_of_requests
1 2
3 3
8 71084
9 1
12 4
13 34
16 59685
32 35643