All the known heavy code blocks are measured (except object database
access). This should help identify if an optimization is effective or
not. An unoptimized git-status would give something like below (92% of
time is accounted). To sum up the effort of making git scale better:
- read cache line is being addressed by index-helper
- preload/refresh index by watchman
- read packed refs by lmdb backend
- diff-index by rebuilding cache-tree
- read directory by untracked cache and watchman
- write index by split index
- name hash potientially by index-helper
read-cache.c:2075 performance: 0.004058570 s: read cache .../index
preload-index.c:104 performance: 0.004419864 s: preload index
read-cache.c:1265 performance: 0.000185224 s: refresh index
refs/files-backend.c:1100 performance: 0.001935788 s: read packed refs
diff-lib.c:240 performance: 0.000144132 s: diff-files
diff-lib.c:506 performance: 0.013592000 s: diff-index
name-hash.c:128 performance: 0.000614177 s: initialize name hash
dir.c:2030 performance: 0.015814103 s: read directory
read-cache.c:2565 performance: 0.004052343 s: write index, changed mask
= 2
trace.c:420 performance: 0.048365509 s: git command: './git'
'status'
Signed-off-by: Nguyễn Thái Ngọc Duy <pclo...@gmail.com>
---
This is worth merging, I think.
diff-lib.c | 4 ++++
dir.c | 2 ++
name-hash.c | 2 ++
preload-index.c | 2 ++
read-cache.c | 11 +++++++++++
refs/files-backend.c | 2 ++
6 files changed, 23 insertions(+)
diff --git a/diff-lib.c b/diff-lib.c
index bc49c70..7af7f9a 100644
--- a/diff-lib.c
+++ b/diff-lib.c
@@ -90,6 +90,7 @@ int run_diff_files(struct rev_info *revs, unsigned int option)
int diff_unmerged_stage = revs->max_count;
unsigned ce_option = ((option & DIFF_RACY_IS_MODIFIED)
? CE_MATCH_RACY_IS_DIRTY : 0);
+ uint64_t start = getnanotime();
diff_set_mnemonic_prefix(&revs->diffopt, "i/", "w/");
@@ -236,6 +237,7 @@ int run_diff_files(struct rev_info *revs, unsigned int
option)
}
diffcore_std(&revs->diffopt);
diff_flush(&revs->diffopt);
+ trace_performance_since(start, "diff-files");
return 0;
}
@@ -491,6 +493,7 @@ static int diff_cache(struct rev_info *revs,
int run_diff_index(struct rev_info *revs, int cached)
{
struct object_array_entry *ent;
+ uint64_t start = getnanotime();
ent = revs->pending.objects;
if (diff_cache(revs, ent->item->oid.hash, ent->name, cached))
@@ -500,6 +503,7 @@ int run_diff_index(struct rev_info *revs, int cached)
diffcore_fix_diff_index(&revs->diffopt);
diffcore_std(&revs->diffopt);
diff_flush(&revs->diffopt);
+ trace_performance_since(start, "diff-index");
return 0;
}
diff --git a/dir.c b/dir.c
index 91003e5..1ebf9fe 100644
--- a/dir.c
+++ b/dir.c
@@ -1991,6 +1991,7 @@ int read_directory(struct dir_struct *dir, const char
*path, int len, const stru
{
struct path_simplify *simplify;
struct untracked_cache_dir *untracked;
+ uint64_t start = getnanotime();
/*
* Check out create_simplify()
@@ -2026,6 +2027,7 @@ int read_directory(struct dir_struct *dir, const char
*path, int len, const stru
free_simplify(simplify);
qsort(dir->entries, dir->nr, sizeof(struct dir_entry *), cmp_name);
qsort(dir->ignored, dir->ignored_nr, sizeof(struct dir_entry *),
cmp_name);
+ trace_performance_since(start, "read directory %.*s", len, path);
if (dir->untracked) {
static struct trace_key trace_untracked_stats =
TRACE_KEY_INIT(UNTRACKED_STATS);
trace_printf_key(&trace_untracked_stats,
diff --git a/name-hash.c b/name-hash.c
index 6d9f23e..b3966d8 100644
--- a/name-hash.c
+++ b/name-hash.c
@@ -115,6 +115,7 @@ static int cache_entry_cmp(const struct cache_entry *ce1,
static void lazy_init_name_hash(struct index_state *istate)
{
int nr;
+ uint64_t start = getnanotime();
if (istate->name_hash_initialized)
return;
@@ -124,6 +125,7 @@ static void lazy_init_name_hash(struct index_state *istate)
for (nr = 0; nr < istate->cache_nr; nr++)
hash_index_entry(istate, istate->cache[nr]);
istate->name_hash_initialized = 1;
+ trace_performance_since(start, "initialize name hash");
}
void add_name_hash(struct index_state *istate, struct cache_entry *ce)
diff --git a/preload-index.c b/preload-index.c
index c1fe3a3..7bb4809 100644
--- a/preload-index.c
+++ b/preload-index.c
@@ -72,6 +72,7 @@ static void preload_index(struct index_state *index,
{
int threads, i, work, offset;
struct thread_data data[MAX_PARALLEL];
+ uint64_t start = getnanotime();
if (!core_preload_index)
return;
@@ -100,6 +101,7 @@ static void preload_index(struct index_state *index,
if (pthread_join(p->pthread, NULL))
die("unable to join threaded lstat");
}
+ trace_performance_since(start, "preload index");
}
#endif
diff --git a/read-cache.c b/read-cache.c
index a73487e..3a79581 100644
--- a/read-cache.c
+++ b/read-cache.c
@@ -1187,6 +1187,7 @@ int refresh_index(struct index_state *istate, unsigned
int flags,
const char *typechange_fmt;
const char *added_fmt;
const char *unmerged_fmt;
+ uint64_t start = getnanotime();
modified_fmt = (in_porcelain ? "M\t%s\n" : "%s: needs update\n");
deleted_fmt = (in_porcelain ? "D\t%s\n" : "%s: needs update\n");
@@ -1261,6 +1262,7 @@ int refresh_index(struct index_state *istate, unsigned
int flags,
replace_index_entry(istate, i, new);
}
+ trace_performance_since(start, "refresh index");
return has_errors;
}
@@ -2062,12 +2064,15 @@ int read_index_from(struct index_state *istate, const
char *path)
{
struct split_index *split_index;
int ret;
+ uint64_t start;
/* istate->initialized covers both .git/index and .git/sharedindex.xxx
*/
if (istate->initialized)
return istate->cache_nr;
+ start = getnanotime();
ret = do_read_index(istate, path, 0);
+ trace_performance_since(start, "read cache %s", path);
split_index = istate->split_index;
if (!split_index || is_null_sha1(split_index->base_sha1)) {
@@ -2082,6 +2087,7 @@ int read_index_from(struct index_state *istate, const
char *path)
split_index->base->keep_mmap = istate->keep_mmap;
split_index->base->to_shm = istate->to_shm;
split_index->base->from_shm = istate->from_shm;
+ start = getnanotime();
ret = do_read_index(split_index->base,
git_path("sharedindex.%s",
sha1_to_hex(split_index->base_sha1)), 1);
@@ -2093,6 +2099,9 @@ int read_index_from(struct index_state *istate, const
char *path)
sha1_to_hex(split_index->base->sha1));
merge_base_index(istate);
post_read_index_from(istate);
+ trace_performance_since(start, "read cache %s",
+ git_path("sharedindex.%s",
+ sha1_to_hex(split_index->base_sha1)));
done:
if (ret > 0 && istate->from_shm && istate->last_update)
@@ -2437,6 +2446,7 @@ static int do_write_index(struct index_state *istate, int
newfd,
int entries = istate->cache_nr;
struct stat st;
struct strbuf previous_name_buf = STRBUF_INIT, *previous_name;
+ uint64_t start = getnanotime();
for (i = removed = extended = 0; i < entries; i++) {
if (cache[i]->ce_flags & CE_REMOVE)
@@ -2552,6 +2562,7 @@ static int do_write_index(struct index_state *istate, int
newfd,
return -1;
istate->timestamp.sec = (unsigned int)st.st_mtime;
istate->timestamp.nsec = ST_MTIME_NSEC(st);
+ trace_performance_since(start, "write index, changed mask = %x",
istate->cache_changed);
return 0;
}
diff --git a/refs/files-backend.c b/refs/files-backend.c
index ea78ce9..b88913f 100644
--- a/refs/files-backend.c
+++ b/refs/files-backend.c
@@ -1048,6 +1048,7 @@ static void read_packed_refs(FILE *f, struct ref_dir *dir)
struct ref_entry *last = NULL;
struct strbuf line = STRBUF_INIT;
enum { PEELED_NONE, PEELED_TAGS, PEELED_FULLY } peeled = PEELED_NONE;
+ uint64_t start = getnanotime();
while (strbuf_getwholeline(&line, f, '\n') != EOF) {
unsigned char sha1[20];
@@ -1096,6 +1097,7 @@ static void read_packed_refs(FILE *f, struct ref_dir *dir)
}
strbuf_release(&line);
+ trace_performance_since(start, "read packed refs");
}
/*
--
2.8.0.rc0.210.gd302cd2
--
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