From 5389146191b279ca3b90028357dd6ad66b283def Mon Sep 17 00:00:00 2001
From: Jason Evans <je@fb.com>
Date: Mon, 13 Feb 2012 18:23:41 -0800
Subject: Remove the opt.lg_prof_bt_max option.
Remove opt.lg_prof_bt_max, and hard code it to 7. The original
intention of this option was to enable faster backtracing by limiting
backtrace depth. However, this makes graphical pprof output very
difficult to interpret. In practice, decreasing sampling frequency is a
better mechanism for limiting profiling overhead.
---
doc/jemalloc.xml.in | 16 ----------------
include/jemalloc/internal/prof.h | 30 ++++++++++--------------------
src/ctl.c | 3 ---
src/jemalloc.c | 2 --
src/prof.c | 22 ++++++++--------------
src/stats.c | 6 ------
6 files changed, 18 insertions(+), 61 deletions(-)
diff --git a/doc/jemalloc.xml.in b/doc/jemalloc.xml.in
index 2e5f10e..1e8c800 100644
--- a/doc/jemalloc.xml.in
+++ b/doc/jemalloc.xml.in
@@ -930,8 +930,6 @@ malloc_conf = "xmalloc:true";]]></programlisting>
where <literal><prefix></literal> is controlled by the <link
linkend="opt.prof_prefix"><mallctl>opt.prof_prefix</mallctl></link>
option. See the <link
- linkend="opt.lg_prof_bt_max"><mallctl>opt.lg_prof_bt_max</mallctl></link>
- option for backtrace depth control. See the <link
linkend="opt.prof_active"><mallctl>opt.prof_active</mallctl></link>
option for on-the-fly activation/deactivation. See the <link
linkend="opt.lg_prof_sample"><mallctl>opt.lg_prof_sample</mallctl></link>
@@ -962,17 +960,6 @@ malloc_conf = "xmalloc:true";]]></programlisting>
<filename>jeprof</filename>.</para></listitem>
</varlistentry>
- <varlistentry id="opt.lg_prof_bt_max">
- <term>
- <mallctl>opt.lg_prof_bt_max</mallctl>
- (<type>size_t</type>)
- <literal>r-</literal>
- [<option>--enable-prof</option>]
- </term>
- <listitem><para>Maximum backtrace depth (log base 2) when profiling
- memory allocation activity. The default is 128 (2^7).</para></listitem>
- </varlistentry>
-
<varlistentry id="opt.prof_active">
<term>
<mallctl>opt.prof_active</mallctl>
@@ -1067,9 +1054,6 @@ malloc_conf = "xmalloc:true";]]></programlisting>
<citerefentry><refentrytitle>atexit</refentrytitle>
<manvolnum>3</manvolnum></citerefentry> function to report memory leaks
detected by allocation sampling. See the
- <link
- linkend="opt.lg_prof_bt_max"><mallctl>opt.lg_prof_bt_max</mallctl></link>
- option for backtrace depth control. See the
<link linkend="opt.prof"><mallctl>opt.prof</mallctl></link> option for
information on analyzing heap profile output. This option is disabled
by default.</para></listitem>
diff --git a/include/jemalloc/internal/prof.h b/include/jemalloc/internal/prof.h
index ad8bcd2..744d361 100644
--- a/include/jemalloc/internal/prof.h
+++ b/include/jemalloc/internal/prof.h
@@ -9,24 +9,18 @@ typedef struct prof_tdata_s prof_tdata_t;
/* Option defaults. */
#define PROF_PREFIX_DEFAULT "jeprof"
-#define LG_PROF_BT_MAX_DEFAULT 7
#define LG_PROF_SAMPLE_DEFAULT 0
#define LG_PROF_INTERVAL_DEFAULT -1
-/* Maximum number of backtraces to store in each per thread LRU cache. */
-#define PROF_TCMAX 1024
-
/*
- * Hard limit on stack backtrace depth. Note that the version of
- * prof_backtrace() that is based on __builtin_return_address() necessarily has
- * a hard-coded number of backtrace frame handlers.
+ * Hard limit on stack backtrace depth. The version of prof_backtrace() that
+ * is based on __builtin_return_address() necessarily has a hard-coded number
+ * of backtrace frame handlers, and should be kept in sync with this setting.
*/
-#if (defined(JEMALLOC_PROF_LIBGCC) || defined(JEMALLOC_PROF_LIBUNWIND))
-# define LG_PROF_BT_MAX ((ZU(1) << (LG_SIZEOF_PTR+3)) - 1)
-#else
-# define LG_PROF_BT_MAX 7 /* >= LG_PROF_BT_MAX_DEFAULT */
-#endif
-#define PROF_BT_MAX (1U << LG_PROF_BT_MAX)
+#define PROF_BT_MAX 128
+
+/* Maximum number of backtraces to store in each per thread LRU cache. */
+#define PROF_TCMAX 1024
/* Initial hash table size. */
#define PROF_CKH_MINITEMS 64
@@ -163,7 +157,6 @@ extern bool opt_prof;
* to notice state changes.
*/
extern bool opt_prof_active;
-extern size_t opt_lg_prof_bt_max; /* Maximum backtrace depth. */
extern size_t opt_lg_prof_sample; /* Mean bytes between samples. */
extern ssize_t opt_lg_prof_interval; /* lg(prof_interval). */
extern bool opt_prof_gdump; /* High-water memory dumping. */
@@ -186,9 +179,6 @@ extern uint64_t prof_interval;
*/
extern bool prof_promote;
-/* (1U << opt_lg_prof_bt_max). */
-extern unsigned prof_bt_max;
-
/* Thread-specific backtrace cache, used to reduce bt2ctx contention. */
#ifndef NO_TLS
extern __thread prof_tdata_t *prof_tdata_tls
@@ -213,7 +203,7 @@ extern __thread prof_tdata_t *prof_tdata_tls
extern pthread_key_t prof_tdata_tsd;
void bt_init(prof_bt_t *bt, void **vec);
-void prof_backtrace(prof_bt_t *bt, unsigned nignore, unsigned max);
+void prof_backtrace(prof_bt_t *bt, unsigned nignore);
prof_thr_cnt_t *prof_lookup(prof_bt_t *bt);
void prof_idump(void);
bool prof_mdump(const char *filename);
@@ -249,7 +239,7 @@ bool prof_boot2(void);
/* Don't bother with sampling logic, since sampling */\
/* interval is 1. */\
bt_init(&bt, prof_tdata->vec); \
- prof_backtrace(&bt, nignore, prof_bt_max); \
+ prof_backtrace(&bt, nignore); \
ret = prof_lookup(&bt); \
} else { \
if (prof_tdata->threshold == 0) { \
@@ -272,7 +262,7 @@ bool prof_boot2(void);
if (size >= prof_tdata->threshold - \
prof_tdata->accum) { \
bt_init(&bt, prof_tdata->vec); \
- prof_backtrace(&bt, nignore, prof_bt_max); \
+ prof_backtrace(&bt, nignore); \
ret = prof_lookup(&bt); \
} else \
ret = (prof_thr_cnt_t *)(uintptr_t)1U; \
diff --git a/src/ctl.c b/src/ctl.c
index 12b4185..4938e10 100644
--- a/src/ctl.c
+++ b/src/ctl.c
@@ -74,7 +74,6 @@ CTL_PROTO(opt_lg_tcache_gc_sweep)
CTL_PROTO(opt_prof)
CTL_PROTO(opt_prof_prefix)
CTL_PROTO(opt_prof_active)
-CTL_PROTO(opt_lg_prof_bt_max)
CTL_PROTO(opt_lg_prof_sample)
CTL_PROTO(opt_lg_prof_interval)
CTL_PROTO(opt_prof_gdump)
@@ -216,7 +215,6 @@ static const ctl_node_t opt_node[] = {
{NAME("prof"), CTL(opt_prof)},
{NAME("prof_prefix"), CTL(opt_prof_prefix)},
{NAME("prof_active"), CTL(opt_prof_active)},
- {NAME("lg_prof_bt_max"), CTL(opt_lg_prof_bt_max)},
{NAME("lg_prof_sample"), CTL(opt_lg_prof_sample)},
{NAME("lg_prof_interval"), CTL(opt_lg_prof_interval)},
{NAME("prof_gdump"), CTL(opt_prof_gdump)},
@@ -1125,7 +1123,6 @@ CTL_RO_NL_CGEN(config_tcache, opt_lg_tcache_gc_sweep, opt_lg_tcache_gc_sweep,
CTL_RO_NL_CGEN(config_prof, opt_prof, opt_prof, bool)
CTL_RO_NL_CGEN(config_prof, opt_prof_prefix, opt_prof_prefix, const char *)
CTL_RO_CGEN(config_prof, opt_prof_active, opt_prof_active, bool) /* Mutable. */
-CTL_RO_NL_CGEN(config_prof, opt_lg_prof_bt_max, opt_lg_prof_bt_max, size_t)
CTL_RO_NL_CGEN(config_prof, opt_lg_prof_sample, opt_lg_prof_sample, size_t)
CTL_RO_NL_CGEN(config_prof, opt_lg_prof_interval, opt_lg_prof_interval, ssize_t)
CTL_RO_NL_CGEN(config_prof, opt_prof_gdump, opt_prof_gdump, bool)
diff --git a/src/jemalloc.c b/src/jemalloc.c
index d2a6009..81829fe 100644
--- a/src/jemalloc.c
+++ b/src/jemalloc.c
@@ -597,8 +597,6 @@ malloc_conf_init(void)
if (config_prof) {
CONF_HANDLE_BOOL(prof)
CONF_HANDLE_CHAR_P(prof_prefix, "jeprof")
- CONF_HANDLE_SIZE_T(lg_prof_bt_max, 0,
- LG_PROF_BT_MAX)
CONF_HANDLE_BOOL(prof_active)
CONF_HANDLE_SSIZE_T(lg_prof_sample, 0,
(sizeof(uint64_t) << 3) - 1)
diff --git a/src/prof.c b/src/prof.c
index a4012f0..21b60e3 100644
--- a/src/prof.c
+++ b/src/prof.c
@@ -16,7 +16,6 @@
bool opt_prof = false;
bool opt_prof_active = true;
-size_t opt_lg_prof_bt_max = LG_PROF_BT_MAX_DEFAULT;
size_t opt_lg_prof_sample = LG_PROF_SAMPLE_DEFAULT;
ssize_t opt_lg_prof_interval = LG_PROF_INTERVAL_DEFAULT;
bool opt_prof_gdump = false;
@@ -27,8 +26,6 @@ char opt_prof_prefix[PATH_MAX + 1];
uint64_t prof_interval;
bool prof_promote;
-unsigned prof_bt_max;
-
#ifndef NO_TLS
__thread prof_tdata_t *prof_tdata_tls
JEMALLOC_ATTR(tls_model("initial-exec"));
@@ -179,7 +176,7 @@ prof_leave(void)
#ifdef JEMALLOC_PROF_LIBUNWIND
void
-prof_backtrace(prof_bt_t *bt, unsigned nignore, unsigned max)
+prof_backtrace(prof_bt_t *bt, unsigned nignore)
{
unw_context_t uc;
unw_cursor_t cursor;
@@ -189,7 +186,6 @@ prof_backtrace(prof_bt_t *bt, unsigned nignore, unsigned max)
cassert(config_prof);
assert(bt->len == 0);
assert(bt->vec != NULL);
- assert(max <= (1U << opt_lg_prof_bt_max));
unw_getcontext(&uc);
unw_init_local(&cursor, &uc);
@@ -205,7 +201,7 @@ prof_backtrace(prof_bt_t *bt, unsigned nignore, unsigned max)
* Iterate over stack frames until there are no more, or until no space
* remains in bt.
*/
- for (i = 0; i < max; i++) {
+ for (i = 0; i < PROF_BT_MAX; i++) {
unw_get_reg(&cursor, UNW_REG_IP, (unw_word_t *)&bt->vec[i]);
bt->len++;
err = unw_step(&cursor);
@@ -243,9 +239,9 @@ prof_unwind_callback(struct _Unwind_Context *context, void *arg)
}
void
-prof_backtrace(prof_bt_t *bt, unsigned nignore, unsigned max)
+prof_backtrace(prof_bt_t *bt, unsigned nignore)
{
- prof_unwind_data_t data = {bt, nignore, max};
+ prof_unwind_data_t data = {bt, nignore, PROF_BT_MAX};
cassert(config_prof);
@@ -253,10 +249,10 @@ prof_backtrace(prof_bt_t *bt, unsigned nignore, unsigned max)
}
#elif (defined(JEMALLOC_PROF_GCC))
void
-prof_backtrace(prof_bt_t *bt, unsigned nignore, unsigned max)
+prof_backtrace(prof_bt_t *bt, unsigned nignore)
{
#define BT_FRAME(i) \
- if ((i) < nignore + max) { \
+ if ((i) < nignore + PROF_BT_MAX) { \
void *p; \
if (__builtin_frame_address(i) == 0) \
return; \
@@ -272,7 +268,6 @@ prof_backtrace(prof_bt_t *bt, unsigned nignore, unsigned max)
cassert(config_prof);
assert(nignore <= 3);
- assert(max <= (1U << opt_lg_prof_bt_max));
BT_FRAME(0)
BT_FRAME(1)
@@ -423,7 +418,7 @@ prof_backtrace(prof_bt_t *bt, unsigned nignore, unsigned max)
}
#else
void
-prof_backtrace(prof_bt_t *bt, unsigned nignore, unsigned max)
+prof_backtrace(prof_bt_t *bt, unsigned nignore)
{
cassert(config_prof);
@@ -1168,7 +1163,7 @@ prof_tdata_init(void)
}
ql_new(&prof_tdata->lru_ql);
- prof_tdata->vec = imalloc(sizeof(void *) * prof_bt_max);
+ prof_tdata->vec = imalloc(sizeof(void *) * PROF_BT_MAX);
if (prof_tdata->vec == NULL) {
ckh_delete(&prof_tdata->bt2cnt);
idalloc(prof_tdata);
@@ -1270,7 +1265,6 @@ prof_boot2(void)
abort();
}
- prof_bt_max = (1U << opt_lg_prof_bt_max);
if (malloc_mutex_init(&prof_dump_seq_mtx))
return (true);
diff --git a/src/stats.c b/src/stats.c
index 86a48c6..6d9ba9d 100644
--- a/src/stats.c
+++ b/src/stats.c
@@ -511,7 +511,6 @@ stats_print(void (*write_cb)(void *, const char *), void *cbopaque,
OPT_WRITE_SSIZE_T(lg_tcache_max)
OPT_WRITE_BOOL(prof)
OPT_WRITE_CHAR_P(prof_prefix)
- OPT_WRITE_SIZE_T(lg_prof_bt_max)
OPT_WRITE_BOOL(prof_active)
OPT_WRITE_SSIZE_T(lg_prof_sample)
OPT_WRITE_BOOL(prof_accum)
@@ -616,11 +615,6 @@ stats_print(void (*write_cb)(void *, const char *), void *cbopaque,
}
if ((err = JEMALLOC_P(mallctl)("opt.prof", &bv, &bsz, NULL, 0))
== 0 && bv) {
- CTL_GET("opt.lg_prof_bt_max", &sv, size_t);
- write_cb(cbopaque, "Maximum profile backtrace depth: ");
- write_cb(cbopaque, u2s((1U << sv), 10, s));
- write_cb(cbopaque, "\n");
-
CTL_GET("opt.lg_prof_sample", &sv, size_t);
write_cb(cbopaque, "Average profile sample interval: ");
write_cb(cbopaque, u2s((((uint64_t)1U) << sv), 10, s));
--
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