trace.h: support nested performance tracing

Performance measurements are listed right now as a flat list, which is
fine when we measure big blocks. But when we start adding more and
more measurements, some of them could be just part of a bigger
measurement and a flat list gives a wrong impression that they are
executed at the same level instead of nested.

Add trace_performance_enter() and trace_performance_leave() to allow
indent these nested measurements. For now it does not help much
because the only nested thing is (lazy) name hash initialization
(e.g. called in diff-index from "git status"). This will help more
because I'm going to add some more tracing that's actually nested.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This commit is contained in:
Nguyễn Thái Ngọc Duy 2018-08-18 16:41:22 +02:00 committed by Junio C Hamano
parent fa03cdc39b
commit c46c406ae1
7 changed files with 96 additions and 20 deletions

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@ -518,11 +518,11 @@ 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();
if (revs->pending.nr != 1)
BUG("run_diff_index must be passed exactly one tree");
trace_performance_enter();
ent = revs->pending.objects;
if (diff_cache(revs, &ent->item->oid, ent->name, cached))
exit(128);
@ -531,7 +531,7 @@ 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");
trace_performance_leave("diff-index");
return 0;
}

9
dir.c
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@ -2263,10 +2263,13 @@ 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))
trace_performance_enter();
if (has_symlink_leading_path(path, len)) {
trace_performance_leave("read directory %.*s", len, path);
return dir->nr;
}
untracked = validate_untracked_cache(dir, len, pathspec);
if (!untracked)
@ -2302,7 +2305,7 @@ int read_directory(struct dir_struct *dir, struct index_state *istate,
dir->nr = i;
}
trace_performance_since(start, "read directory %.*s", len, path);
trace_performance_leave("read directory %.*s", len, path);
if (dir->untracked) {
static int force_untracked_cache = -1;
static struct trace_key trace_untracked_stats = TRACE_KEY_INIT(UNTRACKED_STATS);

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@ -578,10 +578,10 @@ 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;
trace_performance_enter();
hashmap_init(&istate->name_hash, cache_entry_cmp, NULL, istate->cache_nr);
hashmap_init(&istate->dir_hash, dir_entry_cmp, NULL, istate->cache_nr);
@ -602,7 +602,7 @@ static void lazy_init_name_hash(struct index_state *istate)
}
istate->name_hash_initialized = 1;
trace_performance_since(start, "initialize name hash");
trace_performance_leave("initialize name hash");
}
/*

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@ -78,7 +78,6 @@ 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;
@ -88,6 +87,7 @@ static void preload_index(struct index_state *index,
threads = 2;
if (threads < 2)
return;
trace_performance_enter();
if (threads > MAX_PARALLEL)
threads = MAX_PARALLEL;
offset = 0;
@ -109,7 +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");
trace_performance_leave("preload index");
}
#endif

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@ -1476,8 +1476,8 @@ 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();
trace_performance_enter();
modified_fmt = (in_porcelain ? "M\t%s\n" : "%s: needs update\n");
deleted_fmt = (in_porcelain ? "D\t%s\n" : "%s: needs update\n");
typechange_fmt = (in_porcelain ? "T\t%s\n" : "%s needs update\n");
@ -1547,7 +1547,7 @@ int refresh_index(struct index_state *istate, unsigned int flags,
replace_index_entry(istate, i, new_entry);
}
trace_performance_since(start, "refresh index");
trace_performance_leave("refresh index");
return has_errors;
}
@ -2002,7 +2002,6 @@ static void freshen_shared_index(const char *shared_index, int warn)
int read_index_from(struct index_state *istate, const char *path,
const char *gitdir)
{
uint64_t start = getnanotime();
struct split_index *split_index;
int ret;
char *base_oid_hex;
@ -2012,8 +2011,9 @@ int read_index_from(struct index_state *istate, const char *path,
if (istate->initialized)
return istate->cache_nr;
trace_performance_enter();
ret = do_read_index(istate, path, 0);
trace_performance_since(start, "read cache %s", path);
trace_performance_leave("read cache %s", path);
split_index = istate->split_index;
if (!split_index || is_null_oid(&split_index->base_oid)) {
@ -2021,6 +2021,7 @@ int read_index_from(struct index_state *istate, const char *path,
return ret;
}
trace_performance_enter();
if (split_index->base)
discard_index(split_index->base);
else
@ -2037,8 +2038,8 @@ int read_index_from(struct index_state *istate, const char *path,
freshen_shared_index(base_path, 0);
merge_base_index(istate);
post_read_index_from(istate);
trace_performance_since(start, "read cache %s", base_path);
free(base_path);
trace_performance_leave("read cache %s", base_path);
return ret;
}

69
trace.c
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@ -176,10 +176,30 @@ void trace_strbuf_fl(const char *file, int line, struct trace_key *key,
strbuf_release(&buf);
}
static uint64_t perf_start_times[10];
static int perf_indent;
uint64_t trace_performance_enter(void)
{
uint64_t now;
if (!trace_want(&trace_perf_key))
return 0;
now = getnanotime();
perf_start_times[perf_indent] = now;
if (perf_indent + 1 < ARRAY_SIZE(perf_start_times))
perf_indent++;
else
BUG("Too deep indentation");
return now;
}
static void trace_performance_vprintf_fl(const char *file, int line,
uint64_t nanos, const char *format,
va_list ap)
{
static const char space[] = " ";
struct strbuf buf = STRBUF_INIT;
if (!prepare_trace_line(file, line, &trace_perf_key, &buf))
@ -188,7 +208,10 @@ static void trace_performance_vprintf_fl(const char *file, int line,
strbuf_addf(&buf, "performance: %.9f s", (double) nanos / 1000000000);
if (format && *format) {
strbuf_addstr(&buf, ": ");
if (perf_indent >= strlen(space))
BUG("Too deep indentation");
strbuf_addf(&buf, ":%.*s ", perf_indent, space);
strbuf_vaddf(&buf, format, ap);
}
@ -244,6 +267,24 @@ void trace_performance_since(uint64_t start, const char *format, ...)
va_end(ap);
}
void trace_performance_leave(const char *format, ...)
{
va_list ap;
uint64_t since;
if (perf_indent)
perf_indent--;
if (!format) /* Allow callers to leave without tracing anything */
return;
since = perf_start_times[perf_indent];
va_start(ap, format);
trace_performance_vprintf_fl(NULL, 0, getnanotime() - since,
format, ap);
va_end(ap);
}
#else
void trace_printf_key_fl(const char *file, int line, struct trace_key *key,
@ -273,6 +314,24 @@ void trace_performance_fl(const char *file, int line, uint64_t nanos,
va_end(ap);
}
void trace_performance_leave_fl(const char *file, int line,
uint64_t nanos, const char *format, ...)
{
va_list ap;
uint64_t since;
if (perf_indent)
perf_indent--;
if (!format) /* Allow callers to leave without tracing anything */
return;
since = perf_start_times[perf_indent];
va_start(ap, format);
trace_performance_vprintf_fl(file, line, nanos - since, format, ap);
va_end(ap);
}
#endif /* HAVE_VARIADIC_MACROS */
@ -411,13 +470,11 @@ uint64_t getnanotime(void)
}
}
static uint64_t command_start_time;
static struct strbuf command_line = STRBUF_INIT;
static void print_command_performance_atexit(void)
{
trace_performance_since(command_start_time, "git command:%s",
command_line.buf);
trace_performance_leave("git command:%s", command_line.buf);
}
void trace_command_performance(const char **argv)
@ -425,10 +482,10 @@ void trace_command_performance(const char **argv)
if (!trace_want(&trace_perf_key))
return;
if (!command_start_time)
if (!command_line.len)
atexit(print_command_performance_atexit);
strbuf_reset(&command_line);
sq_quote_argv_pretty(&command_line, argv);
command_start_time = getnanotime();
trace_performance_enter();
}

15
trace.h
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@ -23,6 +23,7 @@ extern void trace_disable(struct trace_key *key);
extern uint64_t getnanotime(void);
extern void trace_command_performance(const char **argv);
extern void trace_verbatim(struct trace_key *key, const void *buf, unsigned len);
uint64_t trace_performance_enter(void);
#ifndef HAVE_VARIADIC_MACROS
@ -45,6 +46,9 @@ extern void trace_performance(uint64_t nanos, const char *format, ...);
__attribute__((format (printf, 2, 3)))
extern void trace_performance_since(uint64_t start, const char *format, ...);
__attribute__((format (printf, 1, 2)))
void trace_performance_leave(const char *format, ...);
#else
/*
@ -118,6 +122,14 @@ extern void trace_performance_since(uint64_t start, const char *format, ...);
__VA_ARGS__); \
} while (0)
#define trace_performance_leave(...) \
do { \
if (trace_pass_fl(&trace_perf_key)) \
trace_performance_leave_fl(TRACE_CONTEXT, __LINE__, \
getnanotime(), \
__VA_ARGS__); \
} while (0)
/* backend functions, use non-*fl macros instead */
__attribute__((format (printf, 4, 5)))
extern void trace_printf_key_fl(const char *file, int line, struct trace_key *key,
@ -130,6 +142,9 @@ extern void trace_strbuf_fl(const char *file, int line, struct trace_key *key,
__attribute__((format (printf, 4, 5)))
extern void trace_performance_fl(const char *file, int line,
uint64_t nanos, const char *fmt, ...);
__attribute__((format (printf, 4, 5)))
extern void trace_performance_leave_fl(const char *file, int line,
uint64_t nanos, const char *fmt, ...);
static inline int trace_pass_fl(struct trace_key *key)
{
return key->fd || !key->initialized;