* [PATCH] Add git-grep threads-num param
@ 2015-10-22 13:23 Victor Leschuk
2015-10-22 14:23 ` John Keeping
0 siblings, 1 reply; 4+ messages in thread
From: Victor Leschuk @ 2015-10-22 13:23 UTC (permalink / raw)
To: git; +Cc: Victor Leschuk
Hello 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(-)
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
^ permalink raw reply related [flat|nested] 4+ messages in thread* Re: [PATCH] Add git-grep threads-num param
2015-10-22 13:23 [PATCH] Add git-grep threads-num param Victor Leschuk
@ 2015-10-22 14:23 ` John Keeping
2015-10-22 20:39 ` Victor Leschuk
2015-10-22 20:40 ` Junio C Hamano
0 siblings, 2 replies; 4+ messages in thread
From: John Keeping @ 2015-10-22 14:23 UTC (permalink / raw)
To: Victor Leschuk; +Cc: git, Victor Leschuk
On Thu, Oct 22, 2015 at 04:23:56PM +0300, Victor Leschuk wrote:
> Hello 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.
For git-pack-objects we call the command-line parameter "--threads" and
the config variable "pack.threads". Is there a reason not to use the
same name here (i.e. "--threads" and "grep.threads")?
> 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(-)
>
> 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
^ permalink raw reply [flat|nested] 4+ messages in thread* RE: [PATCH] Add git-grep threads-num param
2015-10-22 14:23 ` John Keeping
@ 2015-10-22 20:39 ` Victor Leschuk
2015-10-22 20:40 ` Junio C Hamano
1 sibling, 0 replies; 4+ messages in thread
From: Victor Leschuk @ 2015-10-22 20:39 UTC (permalink / raw)
To: John Keeping, Victor Leschuk; +Cc: git@vger.kernel.org
Hello John,
I haven't noticed the --threads option in pack-objects, I will fix the patch to make naming more uniform. Do you have any comments regarding the functionality?
--
Best Regards,
Victor
________________________________________
From: John Keeping [john@keeping.me.uk]
Sent: Thursday, October 22, 2015 7:23 AM
To: Victor Leschuk
Cc: git@vger.kernel.org; Victor Leschuk
Subject: Re: [PATCH] Add git-grep threads-num param
On Thu, Oct 22, 2015 at 04:23:56PM +0300, Victor Leschuk wrote:
> Hello 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.
For git-pack-objects we call the command-line parameter "--threads" and
the config variable "pack.threads". Is there a reason not to use the
same name here (i.e. "--threads" and "grep.threads")?
> 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(-)
>
> 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
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH] Add git-grep threads-num param
2015-10-22 14:23 ` John Keeping
2015-10-22 20:39 ` Victor Leschuk
@ 2015-10-22 20:40 ` Junio C Hamano
1 sibling, 0 replies; 4+ messages in thread
From: Junio C Hamano @ 2015-10-22 20:40 UTC (permalink / raw)
To: Victor Leschuk; +Cc: John Keeping, git, Victor Leschuk
John Keeping <john@keeping.me.uk> writes:
> On Thu, Oct 22, 2015 at 04:23:56PM +0300, Victor Leschuk wrote:
>> Hello 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.
>
> For git-pack-objects we call the command-line parameter "--threads" and
> the config variable "pack.threads". Is there a reason not to use the
> same name here (i.e. "--threads" and "grep.threads")?
Good suggestion.
>> +-t <num>::
>> +--threads-num <num>::
>> + Set number of worker threads to <num>. Default is 8.
It is not like you would want to specify different degree of
parallelism for every invocation of "grep". The command line option
for this feature is expected to be used extremely infrequently, only
to defeat a configuration variable that is misconfigured to a wrong
value. Squatting on a short-and-sweet single-letter option name is
unwarranted for an option like this.
>> - for (i = 0; i < ARRAY_SIZE(threads); i++) {
>> + threads = xmalloc(sizeof(pthread_t) * opt->num_threads);
xcalloc(nmemb, size)?
>> @@ -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);
I do not think anybody checked if opt.num_threads is a sensible
number after parse_options() returned at this point. There is a
code outside the context before this hunk that decides if it makes
sense to use threads and turns use_threads to zero, which should
be the right place to do the missing sanity check, I thinnk.
>> 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 */
>> }
These #ifndef/#endif's are unnecessary distraction. Just set them
unconditionally, even in NO_PTHREADS build (and of course include
the field even in NO_PTHREADS build in grep.h).
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2015-10-22 20:41 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
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2015-10-22 13:23 [PATCH] Add git-grep threads-num param Victor Leschuk
2015-10-22 14:23 ` John Keeping
2015-10-22 20:39 ` Victor Leschuk
2015-10-22 20:40 ` Junio C Hamano
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