git-annotate efficiency

["Morten Welinder" <mwelinder@gmail.com>]

So I wanted to give git-annotate a spin and typed...

    git annotate Makefile

Bad idea.  It's been ten minutes and no output yet.  While the script only
appears to use ~20% of cpu according to top, an strace shows that it
spins off a huge number of very short-lived subprocesses.

Morten




...
rt_sigaction(SIGQUIT, {SIG_IGN}, {SIG_DFL}, 8) = 0
waitpid(1539, [{WIFEXITED(s) && WEXITSTATUS(s) == 0}], 0) = 1539
--- SIGCHLD (Child exited) @ 0 (0) ---
rt_sigaction(SIGHUP, {SIG_DFL}, NULL, 8) = 0
rt_sigaction(SIGINT, {SIG_DFL}, NULL, 8) = 0
rt_sigaction(SIGQUIT, {SIG_DFL}, NULL, 8) = 0
pipe([3, 4])                            = 0
pipe([5, 6])                            = 0
clone(child_stack=0,
flags=CLONE_CHILD_CLEARTID|CLONE_CHILD_SETTID|SIGCHLD,
child_tidptr=0x401db708) = 1540
close(6)                                = 0
close(4)                                = 0
read(5, "", 4)                          = 0
close(5)                                = 0
ioctl(3, SNDCTL_TMR_TIMEBASE or TCGETS, 0xbfffc718) = -1 EINVAL
(Invalid argument)
_llseek(3, 0, 0xbfffc760, SEEK_CUR)     = -1 ESPIPE (Illegal seek)
fcntl64(3, F_SETFD, FD_CLOEXEC)         = 0
read(3, "diff --git a/Makefile b/Makefile"..., 4096) = 63
read(3, "--- a/Makefile\n+++ b/Makefile\n@@"..., 4096) = 203
--- SIGCHLD (Child exited) @ 0 (0) ---
read(3, "", 4096)                       = 0
close(3)                                = 0
rt_sigaction(SIGHUP, {SIG_IGN}, {SIG_DFL}, 8) = 0
rt_sigaction(SIGINT, {SIG_IGN}, {SIG_DFL}, 8) = 0
...