From 578da0391a7958510b960eaf1ef30d13e791554e Mon Sep 17 00:00:00 2001 From: Karsten Blees Date: Sat, 12 Jul 2014 02:07:01 +0200 Subject: [PATCH] git: add performance tracing for git's main() function to debug scripts Use trace_performance to measure and print execution time and command line arguments of the entire main() function. In constrast to the shell's 'time' utility, which measures total time of the parent process, this logs all involved git commands recursively. This is particularly useful to debug performance issues of scripted commands (i.e. which git commands were called with which parameters, and how long did they execute). Due to git's deliberate use of exit(), the implementation uses an atexit routine rather than just adding trace_performance_since() at the end of main(). Usage example: > GIT_TRACE_PERFORMANCE=~/git-trace.log git stash list Creates a log file like this: 23:57:38.638765 trace.c:405 performance: 0.000310107 s: git command: 'git' 'rev-parse' '--git-dir' 23:57:38.644387 trace.c:405 performance: 0.000261759 s: git command: 'git' 'rev-parse' '--show-toplevel' 23:57:38.646207 trace.c:405 performance: 0.000304468 s: git command: 'git' 'config' '--get-colorbool' 'color.interactive' 23:57:38.648491 trace.c:405 performance: 0.000241667 s: git command: 'git' 'config' '--get-color' 'color.interactive.help' 'red bold' 23:57:38.650465 trace.c:405 performance: 0.000243063 s: git command: 'git' 'config' '--get-color' '' 'reset' 23:57:38.654850 trace.c:405 performance: 0.025126313 s: git command: 'git' 'stash' 'list' Signed-off-by: Karsten Blees Signed-off-by: Junio C Hamano --- Documentation/git.txt | 5 +++++ git.c | 2 ++ trace.c | 22 ++++++++++++++++++++++ trace.h | 1 + 4 files changed, 30 insertions(+) diff --git a/Documentation/git.txt b/Documentation/git.txt index 9d073f6adc..fcb8afa200 100644 --- a/Documentation/git.txt +++ b/Documentation/git.txt @@ -938,6 +938,11 @@ Unsetting the variable, or setting it to empty, "0" or starting with "PACK". See 'GIT_TRACE' for available trace output options. +'GIT_TRACE_PERFORMANCE':: + Enables performance related trace messages, e.g. total execution + time of each Git command. + See 'GIT_TRACE' for available trace output options. + 'GIT_TRACE_SETUP':: Enables trace messages printing the .git, working tree and current working directory after Git has completed its setup phase. diff --git a/git.c b/git.c index 7780572948..d4daeb8604 100644 --- a/git.c +++ b/git.c @@ -568,6 +568,8 @@ int main(int argc, char **av) git_setup_gettext(); + trace_command_performance(argv); + /* * "git-xxxx" is the same as "git xxxx", but we obviously: * diff --git a/trace.c b/trace.c index af64dbbcf3..e583dc63bb 100644 --- a/trace.c +++ b/trace.c @@ -404,3 +404,25 @@ inline uint64_t getnanotime(void) return now; } } + +static uint64_t command_start_time; +static struct strbuf command_line = STRBUF_INIT; + +static void print_command_performance_atexit(void) +{ + trace_performance_since(command_start_time, "git command:%s", + command_line.buf); +} + +void trace_command_performance(const char **argv) +{ + if (!trace_want(&trace_perf_key)) + return; + + if (!command_start_time) + atexit(print_command_performance_atexit); + + strbuf_reset(&command_line); + sq_quote_argv(&command_line, argv, 0); + command_start_time = getnanotime(); +} diff --git a/trace.h b/trace.h index c843e681a7..ae6a332947 100644 --- a/trace.h +++ b/trace.h @@ -17,6 +17,7 @@ extern void trace_repo_setup(const char *prefix); extern int trace_want(struct trace_key *key); extern void trace_disable(struct trace_key *key); extern uint64_t getnanotime(void); +extern void trace_command_performance(const char **argv); #ifndef HAVE_VARIADIC_MACROS -- 2.11.4.GIT