During the iteration of the index entries in run_diff_files, whenever a
submodule is found and needs its status checked, a subprocess is spawned
for it. Instead of spawning the subprocess immediately and waiting for
its completion to continue, hold onto all submodules and relevant
information in a list. Then use that list to create tasks for
run_processes_parallel. Subprocess output is passed to
status_on_stderr_output which stores it to be parsed on completion of
the subprocess.
Add config option submodule.diffJobs to set the maximum number of
parallel jobs. The option defaults to 1 if unset. If set to 0, the
number of jobs is set to online_cpus().
Since run_diff_files is called from many different commands, I chose to
grab the config option in the function rather than adding variables to
every git command and then figuring out how to pass them all in.
Signed-off-by: Calvin Wan <calvinwan@xxxxxxxxxx>
---
Documentation/config/submodule.txt | 12 +++
diff-lib.c | 81 +++++++++++++++---
submodule.c | 128 +++++++++++++++++++++++++++++
submodule.h | 9 ++
t/t4027-diff-submodule.sh | 31 +++++++
t/t7506-status-submodule.sh | 25 ++++++
6 files changed, 274 insertions(+), 12 deletions(-)
diff --git a/Documentation/config/submodule.txt b/Documentation/config/submodule.txt
index 6490527b45..3209eb8117 100644
--- a/Documentation/config/submodule.txt
+++ b/Documentation/config/submodule.txt
@@ -93,6 +93,18 @@ submodule.fetchJobs::
in parallel. A value of 0 will give some reasonable default.
If unset, it defaults to 1.
+submodule.diffJobs::
+ Specifies how many submodules are diffed at the same time. A
+ positive integer allows up to that number of submodules diffed
+ in parallel. A value of 0 will give some reasonable default.
+ If unset, it defaults to 1. The diff operation is used by many
+ other git commands such as add, merge, diff, status, stash and
+ more. Note that the expensive part of the diff operation is
+ reading the index from cache or memory. Therefore multiple jobs
+ may be detrimental to performance if your hardware does not
+ support parallel reads or if the number of jobs greatly exceeds
+ the amount of supported reads.
+
submodule.alternateLocation::
Specifies how the submodules obtain alternates when submodules are
cloned. Possible values are `no`, `superproject`.
diff --git a/diff-lib.c b/diff-lib.c
index 744ae98a69..7fe6ced950 100644
--- a/diff-lib.c
+++ b/diff-lib.c
@@ -14,6 +14,7 @@
#include "dir.h"
#include "fsmonitor.h"
#include "commit-reach.h"
+#include "config.h"
/*
* diff-files
@@ -65,26 +66,41 @@ static int check_removed(const struct index_state *istate, const struct cache_en
* Return 1 when changes are detected, 0 otherwise. If the DIRTY_SUBMODULES
* option is set, the caller does not only want to know if a submodule is
* modified at all but wants to know all the conditions that are met (new
- * commits, untracked content and/or modified content).
+ * commits, untracked content and/or modified content). If
+ * defer_submodule_status bit is set, dirty_submodule will be left to the
+ * caller to set. defer_submodule_status can also be set to 0 in this
+ * function if there is no need to check if the submodule is modified.
*/
static int match_stat_with_submodule(struct diff_options *diffopt,
const struct cache_entry *ce,
struct stat *st, unsigned ce_option,
- unsigned *dirty_submodule)
+ unsigned *dirty_submodule, int *defer_submodule_status,
+ unsigned *ignore_untracked)
{
int changed = ie_match_stat(diffopt->repo->index, ce, st, ce_option);
+ int defer = 0;
+
if (S_ISGITLINK(ce->ce_mode)) {
struct diff_flags orig_flags = diffopt->flags;
if (!diffopt->flags.override_submodule_config)
set_diffopt_flags_from_submodule_config(diffopt, ce->name);
- if (diffopt->flags.ignore_submodules)
+ if (diffopt->flags.ignore_submodules) {
changed = 0;
- else if (!diffopt->flags.ignore_dirty_submodules &&
- (!changed || diffopt->flags.dirty_submodules))
- *dirty_submodule = is_submodule_modified(ce->name,
- diffopt->flags.ignore_untracked_in_submodules);
+ } else if (!diffopt->flags.ignore_dirty_submodules &&
+ (!changed || diffopt->flags.dirty_submodules)) {
+ if (defer_submodule_status && *defer_submodule_status) {
+ defer = 1;
+ *ignore_untracked = diffopt->flags.ignore_untracked_in_submodules;
+ } else {
+ *dirty_submodule = is_submodule_modified(ce->name,
+ diffopt->flags.ignore_untracked_in_submodules);
+ }
+ }
diffopt->flags = orig_flags;
}
+
+ if (defer_submodule_status)
+ *defer_submodule_status = defer;
return changed;
}
@@ -124,6 +140,7 @@ int run_diff_files(struct rev_info *revs, unsigned int option)
? CE_MATCH_RACY_IS_DIRTY : 0);
uint64_t start = getnanotime();
struct index_state *istate = revs->diffopt.repo->index;
+ struct string_list submodules = STRING_LIST_INIT_NODUP;
diff_set_mnemonic_prefix(&revs->diffopt, "i/", "w/");
@@ -136,7 +153,7 @@ int run_diff_files(struct rev_info *revs, unsigned int option)
unsigned int newmode;
struct cache_entry *ce = istate->cache[i];
int changed;
- unsigned dirty_submodule = 0;
+ int defer_submodule_status = 1;
if (diff_can_quit_early(&revs->diffopt))
break;
@@ -247,6 +264,7 @@ int run_diff_files(struct rev_info *revs, unsigned int option)
newmode = ce->ce_mode;
} else {
struct stat st;
+ unsigned ignore_untracked = 0;
changed = check_removed(istate, ce, &st);
if (changed) {
@@ -268,13 +286,52 @@ int run_diff_files(struct rev_info *revs, unsigned int option)
}
changed = match_stat_with_submodule(&revs->diffopt, ce, &st,
- ce_option, &dirty_submodule);
+ ce_option, NULL,
+ &defer_submodule_status,
+ &ignore_untracked);
newmode = ce_mode_from_stat(ce, st.st_mode);
+ if (defer_submodule_status) {
+ struct submodule_status_util tmp = {
+ .changed = changed,
+ .dirty_submodule = 0,
+ .ignore_untracked = ignore_untracked,
+ .newmode = newmode,
+ .ce = ce,
+ .path = ce->name,
+ };
+ struct string_list_item *item;
+
+ item = string_list_append(&submodules, ce->name);
+ item->util = xmalloc(sizeof(tmp));
+ memcpy(item->util, &tmp, sizeof(tmp));
+ continue;
+ }
}
- record_file_diff(&revs->diffopt, newmode, dirty_submodule,
- changed, istate, ce);
+ if (!defer_submodule_status)
+ record_file_diff(&revs->diffopt, newmode, 0,
+ changed,istate, ce);
+ }
+ if (submodules.nr) {
+ unsigned long parallel_jobs;
+ struct string_list_item *item;
+
+ if (git_config_get_ulong("submodule.diffjobs", ¶llel_jobs))
+ parallel_jobs = 1;
+ else if (!parallel_jobs)
+ parallel_jobs = online_cpus();
+
+ if (get_submodules_status(&submodules, parallel_jobs))
+ die(_("submodule status failed"));
+ for_each_string_list_item(item, &submodules) {
+ struct submodule_status_util *util = item->util;
+
+ record_file_diff(&revs->diffopt, util->newmode,
+ util->dirty_submodule, util->changed,
+ istate, util->ce);
+ }
}
+ string_list_clear(&submodules, 1);
diffcore_std(&revs->diffopt);
diff_flush(&revs->diffopt);
trace_performance_since(start, "diff-files");
@@ -322,7 +379,7 @@ static int get_stat_data(const struct index_state *istate,
return -1;
}
changed = match_stat_with_submodule(diffopt, ce, &st,
- 0, dirty_submodule);
+ 0, dirty_submodule, NULL, NULL);
if (changed) {
mode = ce_mode_from_stat(ce, st.st_mode);
oid = null_oid();
diff --git a/submodule.c b/submodule.c
index 426074cebb..6f6e150a3f 100644
--- a/submodule.c
+++ b/submodule.c
@@ -1373,6 +1373,13 @@ int submodule_touches_in_range(struct repository *r,
return ret;
}
+struct submodule_parallel_status {
+ size_t index_count;
+ int result;
+
+ struct string_list *submodule_names;
+};
+
struct submodule_parallel_fetch {
/*
* The index of the last index entry processed by
@@ -1455,6 +1462,12 @@ struct fetch_task {
struct oid_array *commits; /* Ensure these commits are fetched */
};
+struct status_task {
+ const char *path;
+ struct strbuf out;
+ int ignore_untracked;
+};
+
/**
* When a submodule is not defined in .gitmodules, we cannot access it
* via the regular submodule-config. Create a fake submodule, which we can
@@ -1981,6 +1994,121 @@ unsigned is_submodule_modified(const char *path, int ignore_untracked)
return dirty_submodule;
}
+static struct status_task *
+get_status_task_from_index(struct submodule_parallel_status *sps,
+ struct strbuf *err)
+{
+ for (; sps->index_count < sps->submodule_names->nr; sps->index_count++) {
+ struct submodule_status_util *util = sps->submodule_names->items[sps->index_count].util;
+ struct status_task *task;
+
+ if (!verify_submodule_git_directory(util->path))
+ continue;
+
+ task = xmalloc(sizeof(*task));
+ task->path = util->path;
+ task->ignore_untracked = util->ignore_untracked;
+ strbuf_init(&task->out, 0);
+ sps->index_count++;
+ return task;
+ }
+ return NULL;
+}
+
+static int get_next_submodule_status(struct child_process *cp,
+ struct strbuf *err, void *data,
+ void **task_cb)
+{
+ struct submodule_parallel_status *sps = data;
+ struct status_task *task = get_status_task_from_index(sps, err);
+
+ if (!task)
+ return 0;
+
+ child_process_init(cp);
+ prepare_submodule_repo_env_in_gitdir(&cp->env);
+ prepare_status_porcelain(cp, task->path, task->ignore_untracked);
+ *task_cb = task;
+ return 1;
+}
+
+static int status_start_failure(struct strbuf *err,
+ void *cb, void *task_cb)
+{
+ struct submodule_parallel_status *sps = cb;
+ struct status_task *task = task_cb;
+
+ sps->result = 1;
+ strbuf_addf(err, _(STATUS_PORCELAIN_START_ERROR), task->path);
+ return 0;
+}
+
+static void status_on_stderr_output(struct strbuf *out,
+ size_t offset,
+ void *cb, void *task_cb)
+{
+ struct status_task *task = task_cb;
+
+ strbuf_add(&task->out, out->buf + offset, out->len - offset);
+ strbuf_setlen(out, offset);
+}
+
+static int status_finish(int retvalue, struct strbuf *err,
+ void *cb, void *task_cb)
+{
+ struct submodule_parallel_status *sps = cb;
+ struct status_task *task = task_cb;
+ struct string_list_item *it =
+ string_list_lookup(sps->submodule_names, task->path);
+ struct submodule_status_util *util = it->util;
+ struct string_list list = STRING_LIST_INIT_DUP;
+ struct string_list_item *item;
+
+ if (retvalue) {
+ sps->result = 1;
+ strbuf_addf(err, _(STATUS_PORCELAIN_FAIL_ERROR), task->path);
+ }
+
+ string_list_split(&list, task->out.buf, '\n', -1);
+ for_each_string_list_item(item, &list) {
+ if (parse_status_porcelain(item->string,
+ strlen(item->string),
+ &util->dirty_submodule,
+ util->ignore_untracked))
+ break;
+ }
+ string_list_clear(&list, 0);
+ strbuf_release(&task->out);
+ free(task);
+
+ return 0;
+}
+
+int get_submodules_status(struct string_list *submodules,
+ int max_parallel_jobs)
+{
+ struct submodule_parallel_status sps = {
+ .submodule_names = submodules,
+ };
+ const struct run_process_parallel_opts opts = {
+ .tr2_category = "submodule",
+ .tr2_label = "parallel/status",
+
+ .processes = max_parallel_jobs,
+
+ .get_next_task = get_next_submodule_status,
+ .start_failure = status_start_failure,
+ .on_stderr_output = status_on_stderr_output,
+ .task_finished = status_finish,
+ .data = &sps,
+ };
+
+ string_list_sort(sps.submodule_names);
+ run_processes_parallel(&opts);
+
+ return sps.result;
+}
+
int submodule_uses_gitfile(const char *path)
{
struct child_process cp = CHILD_PROCESS_INIT;
diff --git a/submodule.h b/submodule.h
index b52a4ff1e7..08d278a414 100644
--- a/submodule.h
+++ b/submodule.h
@@ -41,6 +41,13 @@ struct submodule_update_strategy {
.type = SM_UPDATE_UNSPECIFIED, \
}
+struct submodule_status_util {
+ int changed, ignore_untracked;
+ unsigned dirty_submodule, newmode;
+ struct cache_entry *ce;
+ const char *path;
+};
+
int is_gitmodules_unmerged(struct index_state *istate);
int is_writing_gitmodules_ok(void);
int is_staging_gitmodules_ok(struct index_state *istate);
@@ -94,6 +101,8 @@ int fetch_submodules(struct repository *r,
int command_line_option,
int default_option,
int quiet, int max_parallel_jobs);
+int get_submodules_status(struct string_list *submodules,
+ int max_parallel_jobs);
unsigned is_submodule_modified(const char *path, int ignore_untracked);
int submodule_uses_gitfile(const char *path);
diff --git a/t/t4027-diff-submodule.sh b/t/t4027-diff-submodule.sh
index 40164ae07d..1c747cc325 100755
--- a/t/t4027-diff-submodule.sh
+++ b/t/t4027-diff-submodule.sh
@@ -34,6 +34,25 @@ test_expect_success setup '
subtip=$3 subprev=$2
'
+test_expect_success 'diff in superproject with submodules respects parallel settings' '
+ test_when_finished "rm -f trace.out" &&
+ (
+ GIT_TRACE=$(pwd)/trace.out git diff &&
+ grep "1 tasks" trace.out &&
+ >trace.out &&
+
+ git config submodule.diffJobs 8 &&
+ GIT_TRACE=$(pwd)/trace.out git diff &&
+ grep "8 tasks" trace.out &&
+ >trace.out &&
+
+ GIT_TRACE=$(pwd)/trace.out git -c submodule.diffJobs=0 diff &&
+ grep "preparing to run up to [0-9]* tasks" trace.out &&
+ ! grep "up to 0 tasks" trace.out &&
+ >trace.out
+ )
+'
+
test_expect_success 'git diff --raw HEAD' '
hexsz=$(test_oid hexsz) &&
git diff --raw --abbrev=$hexsz HEAD >actual &&
@@ -70,6 +89,18 @@ test_expect_success 'git diff HEAD with dirty submodule (work tree)' '
test_cmp expect.body actual.body
'
+test_expect_success 'git diff HEAD with dirty submodule (work tree, parallel)' '
+ (
+ cd sub &&
+ git reset --hard &&
+ echo >>world
+ ) &&
+ git -c submodule.diffJobs=8 diff HEAD >actual &&
+ sed -e "1,/^@@/d" actual >actual.body &&
+ expect_from_to >expect.body $subtip $subprev-dirty &&
+ test_cmp expect.body actual.body
+'
+
test_expect_success 'git diff HEAD with dirty submodule (index)' '
(
cd sub &&
diff --git a/t/t7506-status-submodule.sh b/t/t7506-status-submodule.sh
index d050091345..7da64e4c4c 100755
--- a/t/t7506-status-submodule.sh
+++ b/t/t7506-status-submodule.sh
@@ -412,4 +412,29 @@ test_expect_success 'status with added file in nested submodule (short)' '
EOF
'
+test_expect_success 'status in superproject with submodules respects parallel settings' '
+ test_when_finished "rm -f trace.out" &&
+ (
+ GIT_TRACE=$(pwd)/trace.out git status &&
+ grep "1 tasks" trace.out &&
+ >trace.out &&
+
+ git config submodule.diffJobs 8 &&
+ GIT_TRACE=$(pwd)/trace.out git status &&
+ grep "8 tasks" trace.out &&
+ >trace.out &&
+
+ GIT_TRACE=$(pwd)/trace.out git -c submodule.diffJobs=0 status &&
+ grep "preparing to run up to [0-9]* tasks" trace.out &&
+ ! grep "up to 0 tasks" trace.out &&
+ >trace.out
+ )
+'
+
+test_expect_success 'status in superproject with submodules (parallel)' '
+ git -C super status --porcelain >output &&
+ git -C super -c submodule.diffJobs=8 status --porcelain >output_parallel &&
+ diff output output_parallel
+'
+
test_done
--
2.40.0.rc0.216.gc4246ad0f0-goog
