trace: measure where the time is spent in the index-heavy operations

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:

    0.001791141 s: read cache ...
    0.004011363 s: preload index
    0.000516161 s: refresh index
    0.003139257 s: git command: ... 'status' '--porcelain=2'
    0.006788129 s: diff-files
    0.002090267 s: diff-index
    0.001885735 s: initialize name hash
    0.032013138 s: read directory
    0.051781209 s: git command: './git' 'status'

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/diff-lib.c b/diff-lib.c
index 8104603a3b36f2fd73761db34efde44d5938f68f..a228e1a219b56a6350160b279c86d63de1e42e0e 100644 (file)
--- a/diff-lib.c
+++ b/diff-lib.c
@@ -92,6 +92,7 @@ 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/");
 
@@ -246,6 +247,7 @@ 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;
 }
 
@@ -512,6 +514,7 @@ 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, ent->name, cached))
@@ -521,6 +524,7 @@ 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 7c4b45e30e0ac87527ff0ef3fd8c90670a1e2064..4479a02a4935a57796600a76ba47392a803e50b1 100644 (file)
--- a/dir.c
+++ b/dir.c
@@ -2248,6 +2248,7 @@ int read_directory(struct dir_struct *dir, struct index_state *istate,
                   const char *path, int len, const struct pathspec *pathspec)
 {
        struct untracked_cache_dir *untracked;
+       uint64_t start = getnanotime();
 
        if (has_symlink_leading_path(path, len))
                return dir->nr;
@@ -2286,6 +2287,7 @@ int read_directory(struct dir_struct *dir, struct index_state *istate,
                dir->nr = i;
        }
 
+       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 45c98db0a057e93b5f3f84eba2008da86130010d..ada66f066a002ac5ecb73f94a582d758c0a3a657 100644 (file)
--- a/name-hash.c
+++ b/name-hash.c
@@ -578,6 +578,8 @@ static void threaded_lazy_init_name_hash(
 
 static void lazy_init_name_hash(struct index_state *istate)
 {
+       uint64_t start = getnanotime();
+
        if (istate->name_hash_initialized)
                return;
        hashmap_init(&istate->name_hash, cache_entry_cmp, NULL, istate->cache_nr);
@@ -600,6 +602,7 @@ static void lazy_init_name_hash(struct index_state *istate)
        }
 
        istate->name_hash_initialized = 1;
+       trace_performance_since(start, "initialize name hash");
 }
 
 /*

diff --git a/preload-index.c b/preload-index.c
index 2a83255e4eeaf8e8ce74516880b0333b23d6f583..4d08d4487460f839f39f667c714f1bb85fa1e144 100644 (file)
--- a/preload-index.c
+++ b/preload-index.c
@@ -78,6 +78,7 @@ 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;
@@ -108,6 +109,7 @@ 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 2eb81a66b941325dc339d61a0ab804a60cbb8be2..eac74bc9f17d69c304461a3174e3ee0888ea1be9 100644 (file)
--- a/read-cache.c
+++ b/read-cache.c
@@ -1372,6 +1372,7 @@ 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");
@@ -1442,6 +1443,7 @@ 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;
 }
 
@@ -1873,6 +1875,7 @@ static void freshen_shared_index(char *base_sha1_hex, int warn)
 
 int read_index_from(struct index_state *istate, const char *path)
 {
+       uint64_t start = getnanotime();
        struct split_index *split_index;
        int ret;
        char *base_sha1_hex;
@@ -1883,6 +1886,7 @@ int read_index_from(struct index_state *istate, const char *path)
                return istate->cache_nr;
 
        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)) {
@@ -1906,6 +1910,7 @@ int read_index_from(struct index_state *istate, const char *path)
        freshen_shared_index(base_sha1_hex, 0);
        merge_base_index(istate);
        post_read_index_from(istate);
+       trace_performance_since(start, "read cache %s", base_path);
        return ret;
 }
 
@@ -2234,6 +2239,7 @@ void update_index_if_able(struct index_state *istate, struct lock_file *lockfile
 static int do_write_index(struct index_state *istate, struct tempfile *tempfile,
                          int strip_extensions)
 {
+       uint64_t start = getnanotime();
        int newfd = tempfile->fd;
        git_SHA_CTX c;
        struct cache_header hdr;
@@ -2374,6 +2380,7 @@ static int do_write_index(struct index_state *istate, struct tempfile *tempfile,
                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;
 }