threaded delta search: specify number of threads at run time

This adds a --threads=<n> parameter to 'git pack-objects' with
documentation.

Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This commit is contained in:
Nicolas Pitre 2007-09-10 00:06:11 -04:00 committed by Junio C Hamano
parent 59921b4b3f
commit 367f4a4343
2 changed files with 29 additions and 5 deletions

View File

@ -173,6 +173,14 @@ base-name::
length, this option typically shrinks the resulting
packfile by 3-5 per-cent.
--threads=<n>::
Specifies the number of threads to spawn when searching for best
delta matches. This requires that pack-objects be compiled with
pthreads otherwise this option is ignored with a warning.
This is meant to reduce packing time on multiprocessor machines.
The required amount of memory for the delta search window is
however multiplied by the number of threads.
--index-version=<version>[,<offset>]::
This is intended to be used by the test suite only. It allows
to force the version for the generated pack index, and to force

View File

@ -24,7 +24,7 @@ git-pack-objects [{ -q | --progress | --all-progress }] \n\
[--max-pack-size=N] [--local] [--incremental] \n\
[--window=N] [--window-memory=N] [--depth=N] \n\
[--no-reuse-delta] [--no-reuse-object] [--delta-base-offset] \n\
[--non-empty] [--revs [--unpacked | --all]*] [--reflog] \n\
[--threads=N] [--non-empty] [--revs [--unpacked | --all]*] [--reflog] \n\
[--stdout | base-name] [<ref-list | <object-list]";
struct object_entry {
@ -72,6 +72,7 @@ static int progress = 1;
static int window = 10;
static uint32_t pack_size_limit;
static int depth = 50;
static int delta_search_threads = 1;
static int pack_to_stdout;
static int num_preferred_base;
static struct progress progress_state;
@ -1605,19 +1606,22 @@ static void *threaded_find_deltas(void *arg)
}
}
#define NR_THREADS 4
static void ll_find_deltas(struct object_entry **list, unsigned list_size,
int window, int depth, unsigned *processed)
{
struct thread_params p[NR_THREADS];
struct thread_params p[delta_search_threads];
int i, ret;
unsigned chunk_size;
if (delta_search_threads <= 1) {
find_deltas(list, list_size, window, depth, processed);
return;
}
pthread_mutex_lock(&data_provider);
pthread_mutex_lock(&data_ready);
for (i = 0; i < NR_THREADS; i++) {
for (i = 0; i < delta_search_threads; i++) {
p[i].window = window;
p[i].depth = depth;
p[i].processed = processed;
@ -1900,6 +1904,18 @@ int cmd_pack_objects(int argc, const char **argv, const char *prefix)
usage(pack_usage);
continue;
}
if (!prefixcmp(arg, "--threads=")) {
char *end;
delta_search_threads = strtoul(arg+10, &end, 0);
if (!arg[10] || *end || delta_search_threads < 1)
usage(pack_usage);
#ifndef THREADED_DELTA_SEARCH
if (delta_search_threads > 1)
warning("no threads support, "
"ignoring %s", arg);
#endif
continue;
}
if (!prefixcmp(arg, "--depth=")) {
char *end;
depth = strtoul(arg+8, &end, 0);