Victor LeschukHello all, I suggest we make number of git-grep worker threads a configuration parameter. I have run several tests on systems with different number of CPU cores. It appeared that the hard-coded number 8 lowers performance on both of my systems: on my 4-core and 8-core systems the thread number of 4 worked about 20% faster than default 8. So I think it is better to allow users tune this parameter.
Signed-off-by: Victor Leschuk <vleschuk@accesssoftek.com> --- Documentation/config.txt | 4 ++++ Documentation/git-grep.txt | 5 +++++ builtin/grep.c | 20 +++++++++++++------- contrib/completion/git-completion.bash | 1 + grep.c | 15 +++++++++++++++ grep.h | 4 ++++ 6 files changed, 42 insertions(+), 7 deletions(-)
Show changes to 6 files +42 −7
Documentation/config.txt, Documentation/git-grep.txt, builtin/grep.c, contrib/completion/git-completion.bash, grep.c, grep.h
diff --git a/Documentation/config.txt b/Documentation/config.txt index 391a0c3..c3df20c 100644 --- a/Documentation/config.txt +++ b/Documentation/config.txt @@ -1447,6 +1447,10 @@ grep.extendedRegexp:: option is ignored when the 'grep.patternType' option is set to a value other than 'default'. +grep.threadsNum:: + Number of grep worker threads, use it to tune up performance on + multicore machines. Default value is 8. + gpg.program:: Use this custom program instead of "gpg" found on $PATH when making or verifying a PGP signature. The program must support the diff --git a/Documentation/git-grep.txt b/Documentation/git-grep.txt index 4a44d6d..e9ca265 100644 --- a/Documentation/git-grep.txt +++ b/Documentation/git-grep.txt @@ -22,6 +22,7 @@ SYNOPSIS [--color[=<when>] | --no-color] [--break] [--heading] [-p | --show-function] [-A <post-context>] [-B <pre-context>] [-C <context>] + [-t <threads-num>] [-W | --function-context] [-f <file>] [-e] <pattern> [--and|--or|--not|(|)|-e <pattern>...] @@ -220,6 +221,10 @@ OPTIONS Show <num> leading lines, and place a line containing `--` between contiguous groups of matches. +-t <num>:: +--threads-num <num>:: + Set number of worker threads to <num>. Default is 8. + -W:: --function-context:: Show the surrounding text from the previous line containing a diff --git a/builtin/grep.c b/builtin/grep.c index d04f440..9b4fc47 100644 --- a/builtin/grep.c +++ b/builtin/grep.c @@ -27,8 +27,7 @@ static char const * const grep_usage[] = { static int use_threads = 1; #ifndef NO_PTHREADS -#define THREADS 8 -static pthread_t threads[THREADS]; +static pthread_t *threads; /* We use one producer thread and THREADS consumer * threads. The producer adds struct work_items to 'todo' and the @@ -206,7 +205,8 @@ static void start_threads(struct grep_opt *opt) strbuf_init(&todo[i].out, 0); } - for (i = 0; i < ARRAY_SIZE(threads); i++) { + threads = xmalloc(sizeof(pthread_t) * opt->num_threads); + for (i = 0; i < opt->num_threads; i++) { int err; struct grep_opt *o = grep_opt_dup(opt); o->output = strbuf_out; @@ -220,7 +220,7 @@ static void start_threads(struct grep_opt *opt) } } -static int wait_all(void) +static int wait_all(struct grep_opt *opt) { int hit = 0; int i; @@ -238,12 +238,14 @@ static int wait_all(void) pthread_cond_broadcast(&cond_add); grep_unlock(); - for (i = 0; i < ARRAY_SIZE(threads); i++) { + for (i = 0; i < opt->num_threads; i++) { void *h; pthread_join(threads[i], &h); hit |= (int) (intptr_t) h; } + free(threads); + pthread_mutex_destroy(&grep_mutex); pthread_mutex_destroy(&grep_read_mutex); pthread_mutex_destroy(&grep_attr_mutex); @@ -256,7 +258,7 @@ static int wait_all(void) } #else /* !NO_PTHREADS */ -static int wait_all(void) +static int wait_all(struct grep_opt *opt) { return 0; } @@ -702,6 +704,10 @@ int cmd_grep(int argc, const char **argv, const char *prefix) N_("show <n> context lines before matches")), OPT_INTEGER('A', "after-context", &opt.post_context, N_("show <n> context lines after matches")), +#ifndef NO_PTHREADS + OPT_INTEGER('t', "threads-num", &opt.num_threads, + N_("use <n> worker threads")), +#endif /* !NO_PTHREADS */ OPT_NUMBER_CALLBACK(&opt, N_("shortcut for -C NUM"), context_callback), OPT_BOOL('p', "show-function", &opt.funcname, @@ -910,7 +916,7 @@ int cmd_grep(int argc, const char **argv, const char *prefix) } if (use_threads) - hit |= wait_all(); + hit |= wait_all(&opt); if (hit && show_in_pager) run_pager(&opt, prefix); free_grep_patterns(&opt); diff --git a/contrib/completion/git-completion.bash b/contrib/completion/git-completion.bash index 482ca84..6231595 100644 --- a/contrib/completion/git-completion.bash +++ b/contrib/completion/git-completion.bash @@ -1310,6 +1310,7 @@ _git_grep () --full-name --line-number --extended-regexp --basic-regexp --fixed-strings --perl-regexp + --threads-num --files-with-matches --name-only --files-without-match --max-depth diff --git a/grep.c b/grep.c index 7b2b96a..17e6a7c 100644 --- a/grep.c +++ b/grep.c @@ -40,6 +40,9 @@ void init_grep_defaults(void) color_set(opt->color_selected, ""); color_set(opt->color_sep, GIT_COLOR_CYAN); opt->color = -1; +#ifndef NO_PTHREADS + opt->num_threads = GREP_NUM_THREADS_DEFAULT; +#endif /* !NO_PTHREADS */ } static int parse_pattern_type_arg(const char *opt, const char *arg) @@ -124,6 +127,14 @@ int grep_config(const char *var, const char *value, void *cb) return config_error_nonbool(var); return color_parse(value, color); } + +#ifndef NO_PTHREADS + if (!strcmp(var, "grep.threadsnum")) { + int threads = git_config_int(var, value); + opt->num_threads = (threads >= 0) ? threads : GREP_NUM_THREADS_DEFAULT; + return 0; + } +#endif /* !NO_PTHREADS */ return 0; } @@ -150,6 +161,10 @@ void grep_init(struct grep_opt *opt, const char *prefix) opt->pathname = def->pathname; opt->regflags = def->regflags; opt->relative = def->relative; +#ifndef NO_PTHREADS + if(!opt->num_threads) + opt->num_threads = def->num_threads; +#endif /* !NO_PTHREADS */ color_set(opt->color_context, def->color_context); color_set(opt->color_filename, def->color_filename); diff --git a/grep.h b/grep.h index 95f197a..e4a296b 100644 --- a/grep.h +++ b/grep.h @@ -132,6 +132,10 @@ struct grep_opt { unsigned pre_context; unsigned post_context; unsigned last_shown; +#ifndef NO_PTHREADS +#define GREP_NUM_THREADS_DEFAULT 8 + unsigned num_threads; +#endif /* !NO_PTHREADS */ int show_hunk_mark; int file_break; int heading;
-- 2.6.2.281.gd4b1c9f
