server-skynet-source-3rd-je.../include/jemalloc/internal/prof.h
Jason Evans 9b0cbf0850 Remove support for non-prof-promote heap profiling metadata.
Make promotion of sampled small objects to large objects mandatory, so
that profiling metadata can always be stored in the chunk map, rather
than requiring one pointer per small region in each small-region page
run.  In practice the non-prof-promote code was only useful when using
jemalloc to track all objects and report them as leaks at program exit.
However, Valgrind is at least as good a tool for this particular use
case.

Furthermore, the non-prof-promote code is getting in the way of
some optimizations that will make heap profiling much cheaper for the
predominant use case (sampling a small representative proportion of all
allocations).
2014-04-11 14:24:51 -07:00

608 lines
18 KiB
C

/******************************************************************************/
#ifdef JEMALLOC_H_TYPES
typedef struct prof_bt_s prof_bt_t;
typedef struct prof_cnt_s prof_cnt_t;
typedef struct prof_thr_cnt_s prof_thr_cnt_t;
typedef struct prof_ctx_s prof_ctx_t;
typedef struct prof_tdata_s prof_tdata_t;
/* Option defaults. */
#ifdef JEMALLOC_PROF
# define PROF_PREFIX_DEFAULT "jeprof"
#else
# define PROF_PREFIX_DEFAULT ""
#endif
#define LG_PROF_SAMPLE_DEFAULT 19
#define LG_PROF_INTERVAL_DEFAULT -1
/*
* 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.
*/
#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
/* Size of memory buffer to use when writing dump files. */
#define PROF_DUMP_BUFSIZE 65536
/* Size of stack-allocated buffer used by prof_printf(). */
#define PROF_PRINTF_BUFSIZE 128
/*
* Number of mutexes shared among all ctx's. No space is allocated for these
* unless profiling is enabled, so it's okay to over-provision.
*/
#define PROF_NCTX_LOCKS 1024
/*
* prof_tdata pointers close to NULL are used to encode state information that
* is used for cleaning up during thread shutdown.
*/
#define PROF_TDATA_STATE_REINCARNATED ((prof_tdata_t *)(uintptr_t)1)
#define PROF_TDATA_STATE_PURGATORY ((prof_tdata_t *)(uintptr_t)2)
#define PROF_TDATA_STATE_MAX PROF_TDATA_STATE_PURGATORY
#endif /* JEMALLOC_H_TYPES */
/******************************************************************************/
#ifdef JEMALLOC_H_STRUCTS
struct prof_bt_s {
/* Backtrace, stored as len program counters. */
void **vec;
unsigned len;
};
#ifdef JEMALLOC_PROF_LIBGCC
/* Data structure passed to libgcc _Unwind_Backtrace() callback functions. */
typedef struct {
prof_bt_t *bt;
unsigned nignore;
unsigned max;
} prof_unwind_data_t;
#endif
struct prof_cnt_s {
/*
* Profiling counters. An allocation/deallocation pair can operate on
* different prof_thr_cnt_t objects that are linked into the same
* prof_ctx_t cnts_ql, so it is possible for the cur* counters to go
* negative. In principle it is possible for the *bytes counters to
* overflow/underflow, but a general solution would require something
* like 128-bit counters; this implementation doesn't bother to solve
* that problem.
*/
int64_t curobjs;
int64_t curbytes;
uint64_t accumobjs;
uint64_t accumbytes;
};
struct prof_thr_cnt_s {
/* Linkage into prof_ctx_t's cnts_ql. */
ql_elm(prof_thr_cnt_t) cnts_link;
/* Linkage into thread's LRU. */
ql_elm(prof_thr_cnt_t) lru_link;
/*
* Associated context. If a thread frees an object that it did not
* allocate, it is possible that the context is not cached in the
* thread's hash table, in which case it must be able to look up the
* context, insert a new prof_thr_cnt_t into the thread's hash table,
* and link it into the prof_ctx_t's cnts_ql.
*/
prof_ctx_t *ctx;
/*
* Threads use memory barriers to update the counters. Since there is
* only ever one writer, the only challenge is for the reader to get a
* consistent read of the counters.
*
* The writer uses this series of operations:
*
* 1) Increment epoch to an odd number.
* 2) Update counters.
* 3) Increment epoch to an even number.
*
* The reader must assure 1) that the epoch is even while it reads the
* counters, and 2) that the epoch doesn't change between the time it
* starts and finishes reading the counters.
*/
unsigned epoch;
/* Profiling counters. */
prof_cnt_t cnts;
};
struct prof_ctx_s {
/* Associated backtrace. */
prof_bt_t *bt;
/* Protects nlimbo, cnt_merged, and cnts_ql. */
malloc_mutex_t *lock;
/*
* Number of threads that currently cause this ctx to be in a state of
* limbo due to one of:
* - Initializing per thread counters associated with this ctx.
* - Preparing to destroy this ctx.
* - Dumping a heap profile that includes this ctx.
* nlimbo must be 1 (single destroyer) in order to safely destroy the
* ctx.
*/
unsigned nlimbo;
/* Temporary storage for summation during dump. */
prof_cnt_t cnt_summed;
/* When threads exit, they merge their stats into cnt_merged. */
prof_cnt_t cnt_merged;
/*
* List of profile counters, one for each thread that has allocated in
* this context.
*/
ql_head(prof_thr_cnt_t) cnts_ql;
/* Linkage for list of contexts to be dumped. */
ql_elm(prof_ctx_t) dump_link;
};
typedef ql_head(prof_ctx_t) prof_ctx_list_t;
struct prof_tdata_s {
/*
* Hash of (prof_bt_t *)-->(prof_thr_cnt_t *). Each thread keeps a
* cache of backtraces, with associated thread-specific prof_thr_cnt_t
* objects. Other threads may read the prof_thr_cnt_t contents, but no
* others will ever write them.
*
* Upon thread exit, the thread must merge all the prof_thr_cnt_t
* counter data into the associated prof_ctx_t objects, and unlink/free
* the prof_thr_cnt_t objects.
*/
ckh_t bt2cnt;
/* LRU for contents of bt2cnt. */
ql_head(prof_thr_cnt_t) lru_ql;
/* Backtrace vector, used for calls to prof_backtrace(). */
void **vec;
/* Sampling state. */
uint64_t prng_state;
uint64_t threshold;
uint64_t accum;
/* State used to avoid dumping while operating on prof internals. */
bool enq;
bool enq_idump;
bool enq_gdump;
};
#endif /* JEMALLOC_H_STRUCTS */
/******************************************************************************/
#ifdef JEMALLOC_H_EXTERNS
extern bool opt_prof;
/*
* Even if opt_prof is true, sampling can be temporarily disabled by setting
* opt_prof_active to false. No locking is used when updating opt_prof_active,
* so there are no guarantees regarding how long it will take for all threads
* to notice state changes.
*/
extern bool opt_prof_active;
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. */
extern bool opt_prof_final; /* Final profile dumping. */
extern bool opt_prof_leak; /* Dump leak summary at exit. */
extern bool opt_prof_accum; /* Report cumulative bytes. */
extern char opt_prof_prefix[
/* Minimize memory bloat for non-prof builds. */
#ifdef JEMALLOC_PROF
PATH_MAX +
#endif
1];
/*
* Profile dump interval, measured in bytes allocated. Each arena triggers a
* profile dump when it reaches this threshold. The effect is that the
* interval between profile dumps averages prof_interval, though the actual
* interval between dumps will tend to be sporadic, and the interval will be a
* maximum of approximately (prof_interval * narenas).
*/
extern uint64_t prof_interval;
void bt_init(prof_bt_t *bt, void **vec);
void prof_backtrace(prof_bt_t *bt, unsigned nignore);
prof_thr_cnt_t *prof_lookup(prof_bt_t *bt);
#ifdef JEMALLOC_JET
size_t prof_bt_count(void);
typedef int (prof_dump_open_t)(bool, const char *);
extern prof_dump_open_t *prof_dump_open;
#endif
void prof_idump(void);
bool prof_mdump(const char *filename);
void prof_gdump(void);
prof_tdata_t *prof_tdata_init(void);
void prof_tdata_cleanup(void *arg);
void prof_boot0(void);
void prof_boot1(void);
bool prof_boot2(void);
void prof_prefork(void);
void prof_postfork_parent(void);
void prof_postfork_child(void);
#endif /* JEMALLOC_H_EXTERNS */
/******************************************************************************/
#ifdef JEMALLOC_H_INLINES
#define PROF_ALLOC_PREP(nignore, size, ret) do { \
prof_tdata_t *prof_tdata; \
prof_bt_t bt; \
\
assert(size == s2u(size)); \
\
prof_tdata = prof_tdata_get(true); \
if ((uintptr_t)prof_tdata <= (uintptr_t)PROF_TDATA_STATE_MAX) { \
if (prof_tdata != NULL) \
ret = (prof_thr_cnt_t *)(uintptr_t)1U; \
else \
ret = NULL; \
break; \
} \
\
if (opt_prof_active == false) { \
/* Sampling is currently inactive, so avoid sampling. */\
ret = (prof_thr_cnt_t *)(uintptr_t)1U; \
} else if (opt_lg_prof_sample == 0) { \
/* Don't bother with sampling logic, since sampling */\
/* interval is 1. */\
bt_init(&bt, prof_tdata->vec); \
prof_backtrace(&bt, nignore); \
ret = prof_lookup(&bt); \
} else { \
if (prof_tdata->threshold == 0) { \
/* Initialize. Seed the prng differently for */\
/* each thread. */\
prof_tdata->prng_state = \
(uint64_t)(uintptr_t)&size; \
prof_sample_threshold_update(prof_tdata); \
} \
\
/* Determine whether to capture a backtrace based on */\
/* whether size is enough for prof_accum to reach */\
/* prof_tdata->threshold. However, delay updating */\
/* these variables until prof_{m,re}alloc(), because */\
/* we don't know for sure that the allocation will */\
/* succeed. */\
/* */\
/* Use subtraction rather than addition to avoid */\
/* potential integer overflow. */\
if (size >= prof_tdata->threshold - \
prof_tdata->accum) { \
bt_init(&bt, prof_tdata->vec); \
prof_backtrace(&bt, nignore); \
ret = prof_lookup(&bt); \
} else \
ret = (prof_thr_cnt_t *)(uintptr_t)1U; \
} \
} while (0)
#ifndef JEMALLOC_ENABLE_INLINE
malloc_tsd_protos(JEMALLOC_ATTR(unused), prof_tdata, prof_tdata_t *)
prof_tdata_t *prof_tdata_get(bool create);
void prof_sample_threshold_update(prof_tdata_t *prof_tdata);
prof_ctx_t *prof_ctx_get(const void *ptr);
void prof_ctx_set(const void *ptr, prof_ctx_t *ctx);
bool prof_sample_accum_update(size_t size);
void prof_malloc(const void *ptr, size_t usize, prof_thr_cnt_t *cnt);
void prof_realloc(const void *ptr, size_t usize, prof_thr_cnt_t *cnt,
size_t old_usize, prof_ctx_t *old_ctx);
void prof_free(const void *ptr, size_t size);
#endif
#if (defined(JEMALLOC_ENABLE_INLINE) || defined(JEMALLOC_PROF_C_))
/* Thread-specific backtrace cache, used to reduce bt2ctx contention. */
malloc_tsd_externs(prof_tdata, prof_tdata_t *)
malloc_tsd_funcs(JEMALLOC_INLINE, prof_tdata, prof_tdata_t *, NULL,
prof_tdata_cleanup)
JEMALLOC_INLINE prof_tdata_t *
prof_tdata_get(bool create)
{
prof_tdata_t *prof_tdata;
cassert(config_prof);
prof_tdata = *prof_tdata_tsd_get();
if (create && prof_tdata == NULL)
prof_tdata = prof_tdata_init();
return (prof_tdata);
}
JEMALLOC_INLINE void
prof_sample_threshold_update(prof_tdata_t *prof_tdata)
{
/*
* The body of this function is compiled out unless heap profiling is
* enabled, so that it is possible to compile jemalloc with floating
* point support completely disabled. Avoiding floating point code is
* important on memory-constrained systems, but it also enables a
* workaround for versions of glibc that don't properly save/restore
* floating point registers during dynamic lazy symbol loading (which
* internally calls into whatever malloc implementation happens to be
* integrated into the application). Note that some compilers (e.g.
* gcc 4.8) may use floating point registers for fast memory moves, so
* jemalloc must be compiled with such optimizations disabled (e.g.
* -mno-sse) in order for the workaround to be complete.
*/
#ifdef JEMALLOC_PROF
uint64_t r;
double u;
cassert(config_prof);
/*
* Compute sample threshold as a geometrically distributed random
* variable with mean (2^opt_lg_prof_sample).
*
* __ __
* | log(u) | 1
* prof_tdata->threshold = | -------- |, where p = -------------------
* | log(1-p) | opt_lg_prof_sample
* 2
*
* For more information on the math, see:
*
* Non-Uniform Random Variate Generation
* Luc Devroye
* Springer-Verlag, New York, 1986
* pp 500
* (http://luc.devroye.org/rnbookindex.html)
*/
prng64(r, 53, prof_tdata->prng_state,
UINT64_C(6364136223846793005), UINT64_C(1442695040888963407));
u = (double)r * (1.0/9007199254740992.0L);
prof_tdata->threshold = (uint64_t)(log(u) /
log(1.0 - (1.0 / (double)((uint64_t)1U << opt_lg_prof_sample))))
+ (uint64_t)1U;
#endif
}
JEMALLOC_INLINE prof_ctx_t *
prof_ctx_get(const void *ptr)
{
prof_ctx_t *ret;
arena_chunk_t *chunk;
cassert(config_prof);
assert(ptr != NULL);
chunk = (arena_chunk_t *)CHUNK_ADDR2BASE(ptr);
if (chunk != ptr) {
/* Region. */
ret = arena_prof_ctx_get(ptr);
} else
ret = huge_prof_ctx_get(ptr);
return (ret);
}
JEMALLOC_INLINE void
prof_ctx_set(const void *ptr, prof_ctx_t *ctx)
{
arena_chunk_t *chunk;
cassert(config_prof);
assert(ptr != NULL);
chunk = (arena_chunk_t *)CHUNK_ADDR2BASE(ptr);
if (chunk != ptr) {
/* Region. */
arena_prof_ctx_set(ptr, ctx);
} else
huge_prof_ctx_set(ptr, ctx);
}
JEMALLOC_INLINE bool
prof_sample_accum_update(size_t size)
{
prof_tdata_t *prof_tdata;
cassert(config_prof);
/* Sampling logic is unnecessary if the interval is 1. */
assert(opt_lg_prof_sample != 0);
prof_tdata = prof_tdata_get(false);
if ((uintptr_t)prof_tdata <= (uintptr_t)PROF_TDATA_STATE_MAX)
return (true);
/* Take care to avoid integer overflow. */
if (size >= prof_tdata->threshold - prof_tdata->accum) {
prof_tdata->accum -= (prof_tdata->threshold - size);
/* Compute new sample threshold. */
prof_sample_threshold_update(prof_tdata);
while (prof_tdata->accum >= prof_tdata->threshold) {
prof_tdata->accum -= prof_tdata->threshold;
prof_sample_threshold_update(prof_tdata);
}
return (false);
} else {
prof_tdata->accum += size;
return (true);
}
}
JEMALLOC_INLINE void
prof_malloc(const void *ptr, size_t usize, prof_thr_cnt_t *cnt)
{
cassert(config_prof);
assert(ptr != NULL);
assert(usize == isalloc(ptr, true));
if (opt_lg_prof_sample != 0) {
if (prof_sample_accum_update(usize)) {
/*
* Don't sample. For malloc()-like allocation, it is
* always possible to tell in advance how large an
* object's usable size will be, so there should never
* be a difference between the usize passed to
* PROF_ALLOC_PREP() and prof_malloc().
*/
assert((uintptr_t)cnt == (uintptr_t)1U);
}
}
if ((uintptr_t)cnt > (uintptr_t)1U) {
prof_ctx_set(ptr, cnt->ctx);
cnt->epoch++;
/*********/
mb_write();
/*********/
cnt->cnts.curobjs++;
cnt->cnts.curbytes += usize;
if (opt_prof_accum) {
cnt->cnts.accumobjs++;
cnt->cnts.accumbytes += usize;
}
/*********/
mb_write();
/*********/
cnt->epoch++;
/*********/
mb_write();
/*********/
} else
prof_ctx_set(ptr, (prof_ctx_t *)(uintptr_t)1U);
}
JEMALLOC_INLINE void
prof_realloc(const void *ptr, size_t usize, prof_thr_cnt_t *cnt,
size_t old_usize, prof_ctx_t *old_ctx)
{
prof_thr_cnt_t *told_cnt;
cassert(config_prof);
assert(ptr != NULL || (uintptr_t)cnt <= (uintptr_t)1U);
if (ptr != NULL) {
assert(usize == isalloc(ptr, true));
if (opt_lg_prof_sample != 0) {
if (prof_sample_accum_update(usize)) {
/*
* Don't sample. The usize passed to
* PROF_ALLOC_PREP() was larger than what
* actually got allocated, so a backtrace was
* captured for this allocation, even though
* its actual usize was insufficient to cross
* the sample threshold.
*/
cnt = (prof_thr_cnt_t *)(uintptr_t)1U;
}
}
}
if ((uintptr_t)old_ctx > (uintptr_t)1U) {
told_cnt = prof_lookup(old_ctx->bt);
if (told_cnt == NULL) {
/*
* It's too late to propagate OOM for this realloc(),
* so operate directly on old_cnt->ctx->cnt_merged.
*/
malloc_mutex_lock(old_ctx->lock);
old_ctx->cnt_merged.curobjs--;
old_ctx->cnt_merged.curbytes -= old_usize;
malloc_mutex_unlock(old_ctx->lock);
told_cnt = (prof_thr_cnt_t *)(uintptr_t)1U;
}
} else
told_cnt = (prof_thr_cnt_t *)(uintptr_t)1U;
if ((uintptr_t)told_cnt > (uintptr_t)1U)
told_cnt->epoch++;
if ((uintptr_t)cnt > (uintptr_t)1U) {
prof_ctx_set(ptr, cnt->ctx);
cnt->epoch++;
} else if (ptr != NULL)
prof_ctx_set(ptr, (prof_ctx_t *)(uintptr_t)1U);
/*********/
mb_write();
/*********/
if ((uintptr_t)told_cnt > (uintptr_t)1U) {
told_cnt->cnts.curobjs--;
told_cnt->cnts.curbytes -= old_usize;
}
if ((uintptr_t)cnt > (uintptr_t)1U) {
cnt->cnts.curobjs++;
cnt->cnts.curbytes += usize;
if (opt_prof_accum) {
cnt->cnts.accumobjs++;
cnt->cnts.accumbytes += usize;
}
}
/*********/
mb_write();
/*********/
if ((uintptr_t)told_cnt > (uintptr_t)1U)
told_cnt->epoch++;
if ((uintptr_t)cnt > (uintptr_t)1U)
cnt->epoch++;
/*********/
mb_write(); /* Not strictly necessary. */
}
JEMALLOC_INLINE void
prof_free(const void *ptr, size_t size)
{
prof_ctx_t *ctx = prof_ctx_get(ptr);
cassert(config_prof);
if ((uintptr_t)ctx > (uintptr_t)1) {
prof_thr_cnt_t *tcnt;
assert(size == isalloc(ptr, true));
tcnt = prof_lookup(ctx->bt);
if (tcnt != NULL) {
tcnt->epoch++;
/*********/
mb_write();
/*********/
tcnt->cnts.curobjs--;
tcnt->cnts.curbytes -= size;
/*********/
mb_write();
/*********/
tcnt->epoch++;
/*********/
mb_write();
/*********/
} else {
/*
* OOM during free() cannot be propagated, so operate
* directly on cnt->ctx->cnt_merged.
*/
malloc_mutex_lock(ctx->lock);
ctx->cnt_merged.curobjs--;
ctx->cnt_merged.curbytes -= size;
malloc_mutex_unlock(ctx->lock);
}
}
}
#endif
#endif /* JEMALLOC_H_INLINES */
/******************************************************************************/