Optimize memory allocation

A number of memory allocation optimizations have been implemented. Most
optimizations reduce contention caused by synchronization between
threads during allocation and deallocation of memory. Most notably:
* Synchronization of memory management in scheduler specific allocator
  instances has been rewritten to use lock-free synchronization.
* Synchronization of memory management in scheduler specific
  pre-allocators has been rewritten to use lock-free synchronization.
* The 'mseg_alloc' memory segment allocator now use scheduler specific
  instances instead of one instance. Apart from reducing contention
  this also ensures that memory allocators always create memory
  segments on the local NUMA node on a NUMA system.

1 files changed, 115 insertions, 78 deletions

diff --git a/erts/emulator/sys/common/erl_poll.c b/erts/emulator/sys/common/erl_poll.c
index 9bd64f5908..80db2055a2 100644
--- a/erts/emulator/sys/common/erl_poll.c
+++ b/erts/emulator/sys/common/erl_poll.c
@@ -68,6 +68,7 @@
 #    endif
 #  endif
 #endif
+#include "erl_thr_progress.h"
 #include "erl_driver.h"
 #include "erl_alloc.h"
 
@@ -114,7 +115,7 @@
 #endif
 
 #define ERTS_POLL_USE_WAKEUP_PIPE \
-   (ERTS_POLL_ASYNC_INTERRUPT_SUPPORT || defined(ERTS_SMP))
+   (ERTS_POLL_ASYNC_INTERRUPT_SUPPORT || defined(USE_THREADS))
 
 #ifdef ERTS_SMP
 
@@ -261,7 +262,6 @@ struct ErtsPollSet_ {
 #ifdef ERTS_SMP
     erts_atomic32_t polled;
     erts_smp_mtx_t mtx;
-#elif ERTS_POLL_ASYNC_INTERRUPT_SUPPORT
 #endif
 #if ERTS_POLL_USE_WAKEUP_PIPE
     int wake_fds[2];
@@ -269,10 +269,8 @@ struct ErtsPollSet_ {
 #if ERTS_POLL_USE_FALLBACK
     int fallback_used;
 #endif
-#ifdef ERTS_SMP
+#if defined(USE_THREADS) || ERTS_POLL_ASYNC_INTERRUPT_SUPPORT
     erts_atomic32_t wakeup_state;
-#elif ERTS_POLL_ASYNC_INTERRUPT_SUPPORT
-    volatile int wakeup_state;
 #endif
     erts_smp_atomic32_t timeout;
 #ifdef ERTS_POLL_COUNT_AVOIDED_WAKEUPS
@@ -345,21 +343,16 @@ static void print_misc_debug_info(void);
 static ERTS_INLINE void
 reset_wakeup_state(ErtsPollSet ps)
 {
-#ifdef ERTS_SMP
-    erts_atomic32_set_nob(&ps->wakeup_state, ERTS_POLL_NOT_WOKEN);
-    ERTS_THR_MEMORY_BARRIER;
-#elif ERTS_POLL_ASYNC_INTERRUPT_SUPPORT
-    ps->wakeup_state = 0;
+#if defined(USE_THREADS) || ERTS_POLL_ASYNC_INTERRUPT_SUPPORT
+    erts_atomic32_set_mb(&ps->wakeup_state, ERTS_POLL_NOT_WOKEN);
 #endif
 }
 
 static ERTS_INLINE int
 is_woken(ErtsPollSet ps)
 {
-#ifdef ERTS_SMP
+#if defined(USE_THREADS) || ERTS_POLL_ASYNC_INTERRUPT_SUPPORT
     return erts_atomic32_read_acqb(&ps->wakeup_state) != ERTS_POLL_NOT_WOKEN;
-#elif ERTS_POLL_ASYNC_INTERRUPT_SUPPORT
-    return ps->wakeup_state != ERTS_POLL_NOT_WOKEN;
 #else
     return 0;
 #endif
@@ -368,13 +361,9 @@ is_woken(ErtsPollSet ps)
 static ERTS_INLINE int
 is_interrupted_reset(ErtsPollSet ps)
 {
-#ifdef ERTS_SMP
+#if defined(USE_THREADS) || ERTS_POLL_ASYNC_INTERRUPT_SUPPORT
     return (erts_atomic32_xchg_nob(&ps->wakeup_state, ERTS_POLL_NOT_WOKEN)
 	    == ERTS_POLL_WOKEN_INTR);
-#elif ERTS_POLL_ASYNC_INTERRUPT_SUPPORT
-    int res = ps->wakeup_state == ERTS_POLL_WOKEN_INTR;
-    ps->wakeup_state = ERTS_POLL_NOT_WOKEN;
-    return res;
 #else
     return 0;
 #endif
@@ -383,16 +372,13 @@ is_interrupted_reset(ErtsPollSet ps)
 static ERTS_INLINE void
 woke_up(ErtsPollSet ps)
 {
-#ifdef ERTS_SMP
+#if defined(USE_THREADS) || ERTS_POLL_ASYNC_INTERRUPT_SUPPORT
     erts_aint32_t wakeup_state = erts_atomic32_read_nob(&ps->wakeup_state);
     if (wakeup_state == ERTS_POLL_NOT_WOKEN)
 	(void) erts_atomic32_cmpxchg_nob(&ps->wakeup_state,
 					 ERTS_POLL_WOKEN,
 					 ERTS_POLL_NOT_WOKEN);
     ASSERT(erts_atomic32_read_nob(&ps->wakeup_state) != ERTS_POLL_NOT_WOKEN);
-#elif ERTS_POLL_ASYNC_INTERRUPT_SUPPORT
-    if (ps->wakeup_state == ERTS_POLL_NOT_WOKEN)
-	ps->wakeup_state = ERTS_POLL_WOKEN;
 #endif
 }
 
@@ -403,28 +389,27 @@ woke_up(ErtsPollSet ps)
 #if ERTS_POLL_USE_WAKEUP_PIPE
 
 static ERTS_INLINE void
-wake_poller(ErtsPollSet ps, int interrupted)
+wake_poller(ErtsPollSet ps, int interrupted, int async_signal_safe)
 {
-    int wake = 0;
-#ifdef ERTS_SMP
-    erts_aint32_t wakeup_state;
-    if (!interrupted)
-	wakeup_state = erts_atomic32_cmpxchg_relb(&ps->wakeup_state,
-						  ERTS_POLL_WOKEN,
-						  ERTS_POLL_NOT_WOKEN);
+    int wake;
+    if (async_signal_safe)
+	wake = 1;
     else {
-	/*
-	 * We might unnecessarily write to the pipe, however,
-	 * that isn't problematic.
-	 */
-	wakeup_state = erts_atomic32_read_nob(&ps->wakeup_state);
-	erts_atomic32_set_relb(&ps->wakeup_state, ERTS_POLL_WOKEN_INTR);
+	erts_aint32_t wakeup_state;
+	if (!interrupted)
+	    wakeup_state = erts_atomic32_cmpxchg_relb(&ps->wakeup_state,
+						      ERTS_POLL_WOKEN,
+						      ERTS_POLL_NOT_WOKEN);
+	else {
+	    /*
+	     * We might unnecessarily write to the pipe, however,
+	     * that isn't problematic.
+	     */
+	    wakeup_state = erts_atomic32_read_nob(&ps->wakeup_state);
+	    erts_atomic32_set_relb(&ps->wakeup_state, ERTS_POLL_WOKEN_INTR);
+	}
+	wake = wakeup_state == ERTS_POLL_NOT_WOKEN;
     }
-    wake = wakeup_state == ERTS_POLL_NOT_WOKEN;
-#elif ERTS_POLL_ASYNC_INTERRUPT_SUPPORT
-    wake = ps->wakeup_state == ERTS_POLL_NOT_WOKEN;
-    ps->wakeup_state = interrupted ? ERTS_POLL_WOKEN_INTR : ERTS_POLL_NOT_WOKEN;
-#endif
     /*
      * NOTE: This function might be called from signal handlers in the
      *       non-smp case; therefore, it has to be async-signal safe in
@@ -439,9 +424,17 @@ wake_poller(ErtsPollSet ps, int interrupted)
 	    res = write(ps->wake_fds[1], "!", 1);
 	} while (res < 0 && errno == EINTR);
 	if (res <= 0 && errno != ERRNO_BLOCK) {
-	    fatal_error_async_signal_safe(__FILE__
-					  ":XXX:wake_poller(): "
-					  "Failed to write on wakeup pipe\n");
+	    if (async_signal_safe)
+		fatal_error_async_signal_safe(__FILE__
+					      ":XXX:wake_poller(): "
+					      "Failed to write on wakeup pipe\n");
+	    else
+		fatal_error("%s:%d:wake_poller(): "
+			    "Failed to write to wakeup pipe fd=%d: "
+			    "%s (%d)\n",
+			    __FILE__, __LINE__,
+			    ps->wake_fds[1],
+			    erl_errno_id(errno), errno);
 	}
     }
 }
@@ -449,11 +442,18 @@ wake_poller(ErtsPollSet ps, int interrupted)
 static ERTS_INLINE void
 cleanup_wakeup_pipe(ErtsPollSet ps)
 {
+#if ERTS_POLL_ASYNC_INTERRUPT_SUPPORT
+    int intr = 0;
+#endif
     int fd = ps->wake_fds[0];
     int res;
     do {
 	char buf[32];
 	res = read(fd, buf, sizeof(buf));
+#if ERTS_POLL_ASYNC_INTERRUPT_SUPPORT
+	if (res > 0)
+	    intr = 1;
+#endif
     } while (res > 0 || (res < 0 && errno == EINTR));
     if (res < 0 && errno != ERRNO_BLOCK) {
 	fatal_error("%s:%d:cleanup_wakeup_pipe(): "
@@ -463,6 +463,10 @@ cleanup_wakeup_pipe(ErtsPollSet ps)
 		    fd,
 		    erl_errno_id(errno), errno);
     }
+#if ERTS_POLL_ASYNC_INTERRUPT_SUPPORT
+    if (intr)
+	erts_atomic32_set_nob(&ps->wakeup_state, ERTS_POLL_WOKEN_INTR);
+#endif
 }
 
 static void
@@ -1497,7 +1501,7 @@ ERTS_POLL_EXPORT(erts_poll_controlv)(ErtsPollSet ps,
 
 #ifdef ERTS_SMP
     if (final_do_wake)
-	wake_poller(ps, 0);
+	wake_poller(ps, 0, 0);
 #endif /* ERTS_SMP */
 
 }
@@ -1520,7 +1524,7 @@ ERTS_POLL_EXPORT(erts_poll_control)(ErtsPollSet ps,
 
 #ifdef ERTS_SMP
     if (*do_wake) {
-	wake_poller(ps, 0);
+	wake_poller(ps, 0, 0);
     }
 #endif /* ERTS_SMP */
 
@@ -1893,9 +1897,9 @@ save_poll_result(ErtsPollSet ps, ErtsPollResFd pr[], int max_res,
 }
 
 static ERTS_INLINE int
-check_fd_events(ErtsPollSet ps, SysTimeval *tv, int max_res, int *ps_locked)
+check_fd_events(ErtsPollSet ps, SysTimeval *tv, int max_res)
 {
-    ASSERT(!*ps_locked);
+    int res;
     if (erts_smp_atomic_read_nob(&ps->no_of_user_fds) == 0
 	&& tv->tv_usec == 0 && tv->tv_sec == 0) {
 	/* Nothing to poll and zero timeout; done... */
@@ -1915,16 +1919,23 @@ check_fd_events(ErtsPollSet ps, SysTimeval *tv, int max_res, int *ps_locked)
 		timeout = INT_MAX;
 	    if (max_res > ps->res_events_len)
 		grow_res_events(ps, max_res);
-	    return epoll_wait(ps->kp_fd, ps->res_events, max_res, (int)timeout);
+#ifdef ERTS_SMP
+	    if (timeout)
+		erts_thr_progress_prepare_wait(NULL);
+#endif
+	    res = epoll_wait(ps->kp_fd, ps->res_events, max_res, (int)timeout);
 #elif ERTS_POLL_USE_KQUEUE	/* --- kqueue ------------------------------ */
 	    struct timespec ts;
-	    ts.tv_sec = tv->tv_sec;
-	    ts.tv_nsec = tv->tv_usec*1000;
 	    if (max_res > ps->res_events_len)
 		grow_res_events(ps, max_res);
-	    return kevent(ps->kp_fd, NULL, 0, ps->res_events, max_res, &ts);
+#ifdef ERTS_SMP
+	    if (timeout)
+		erts_thr_progress_prepare_wait(NULL);
+#endif
+	    ts.tv_sec = tv->tv_sec;
+	    ts.tv_nsec = tv->tv_usec*1000;
+	    res = kevent(ps->kp_fd, NULL, 0, ps->res_events, max_res, &ts);
 #endif				/* ----------------------------------------- */
-
 	}
 	else /* use fallback (i.e. poll() or select()) */
 #endif /* ERTS_POLL_USE_FALLBACK */
@@ -1947,22 +1958,38 @@ check_fd_events(ErtsPollSet ps, SysTimeval *tv, int max_res, int *ps_locked)
 	    if (poll_res.dp_nfds > ps->res_events_len)
 		grow_res_events(ps, poll_res.dp_nfds);
 	    poll_res.dp_fds = ps->res_events;
+#ifdef ERTS_SMP
+	    if (timeout)
+		erts_thr_progress_prepare_wait(NULL);
+#endif
 	    poll_res.dp_timeout = (int) timeout;
-	    return ioctl(ps->kp_fd, DP_POLL, &poll_res);
+	    res = ioctl(ps->kp_fd, DP_POLL, &poll_res);
 #elif ERTS_POLL_USE_POLL	/* --- poll -------------------------------- */
 	    if (timeout > INT_MAX)
 		timeout = INT_MAX;
-	    return poll(ps->poll_fds, ps->no_poll_fds, (int) timeout);
+#ifdef ERTS_SMP
+	    if (timeout)
+		erts_thr_progress_prepare_wait(NULL);
+#endif
+	    res = poll(ps->poll_fds, ps->no_poll_fds, (int) timeout);
 #elif ERTS_POLL_USE_SELECT	/* --- select ------------------------------ */
-	    int res;
+	    SysTimeval to = *tv;
+
 	    ps->res_input_fds = ps->input_fds;
 	    ps->res_output_fds = ps->output_fds;
+
+#ifdef ERTS_SMP
+	    if (to.tv_sec || to.tv_usec)
+		erts_thr_progress_prepare_wait(NULL);
+#endif
 	    res = select(ps->max_fd + 1,
 			 &ps->res_input_fds,
 			 &ps->res_output_fds,
 			 NULL,
-			 tv);
+			 &to);
 #ifdef ERTS_SMP
+	    if (to.tv_sec || to.tv_usec)
+		erts_thr_progress_finalize_wait(NULL);
 	    if (res < 0
 		&& errno == EBADF
 		&& ERTS_POLLSET_HAVE_UPDATE_REQUESTS(ps)) {
@@ -1978,15 +2005,16 @@ check_fd_events(ErtsPollSet ps, SysTimeval *tv, int max_res, int *ps_locked)
 		 * have triggered, we fake an EAGAIN error and let the caller
 		 * restart us.
 		 */
-		SysTimeval zero_tv = {0, 0};
-		*ps_locked = 1;
+		to.tv_sec = 0;
+		to.tv_usec = 0;
 		ERTS_POLLSET_LOCK(ps);
 		handle_update_requests(ps);
+		ERTS_POLLSET_UNLOCK(ps);
 		res = select(ps->max_fd + 1,
 			     &ps->res_input_fds,
 			     &ps->res_output_fds,
 			     NULL,
-			     &zero_tv);
+			     &to);
 		if (res == 0) {
 		    errno = EAGAIN;
 		    res = -1;
@@ -1996,6 +2024,11 @@ check_fd_events(ErtsPollSet ps, SysTimeval *tv, int max_res, int *ps_locked)
 	    return res;
 #endif				/* ----------------------------------------- */
 	}
+#ifdef ERTS_SMP
+	if (timeout)
+	    erts_thr_progress_finalize_wait(NULL);
+#endif
+	return res;
     }
 }
 
@@ -2007,7 +2040,9 @@ ERTS_POLL_EXPORT(erts_poll_wait)(ErtsPollSet ps,
 {
     int res, no_fds;
     int ebadf = 0;
-    int ps_locked;
+#ifdef ERTS_SMP
+    int ps_locked = 0;
+#endif
     SysTimeval *tvp;
     SysTimeval itv;
 
@@ -2049,8 +2084,7 @@ ERTS_POLL_EXPORT(erts_poll_wait)(ErtsPollSet ps,
     }
 #endif
 
-    ps_locked = 0;
-    res = check_fd_events(ps, tvp, no_fds, &ps_locked);
+    res = check_fd_events(ps, tvp, no_fds);
 
     woke_up(ps);
 
@@ -2072,10 +2106,8 @@ ERTS_POLL_EXPORT(erts_poll_wait)(ErtsPollSet ps,
 #endif
 
 #ifdef ERTS_SMP
-	if (!ps_locked) {
-	    ps_locked = 1;
-	    ERTS_POLLSET_LOCK(ps);
-	}
+	ps_locked = 1;
+	ERTS_POLLSET_LOCK(ps);
 #endif
 
 	no_fds = save_poll_result(ps, pr, no_fds, res, ebadf);
@@ -2111,19 +2143,26 @@ ERTS_POLL_EXPORT(erts_poll_wait)(ErtsPollSet ps,
 void
 ERTS_POLL_EXPORT(erts_poll_interrupt)(ErtsPollSet ps, int set)
 {
-#if ERTS_POLL_ASYNC_INTERRUPT_SUPPORT || defined(ERTS_SMP)
-    /*
-     * NOTE: This function might be called from signal handlers in the
-     *       non-smp case; therefore, it has to be async-signal safe in
-     *       the non-smp case.
-     */
+#if defined(USE_THREADS)
     if (!set)
 	reset_wakeup_state(ps);
     else
-	wake_poller(ps, 1);
+	wake_poller(ps, 1, 0);
 #endif
 }
 
+#if ERTS_POLL_ASYNC_INTERRUPT_SUPPORT
+void
+ERTS_POLL_EXPORT(erts_poll_async_sig_interrupt)(ErtsPollSet ps)
+{
+    /*
+     * NOTE: This function is called from signal handlers, it,
+     *       therefore, it has to be async-signal safe.
+     */
+    wake_poller(ps, 1, 1);
+}
+#endif
+
 /*
  * erts_poll_interrupt_timed():
  *   If 'set' != 0, interrupt thread blocked in erts_poll_wait() if it
@@ -2139,7 +2178,7 @@ ERTS_POLL_EXPORT(erts_poll_interrupt_timed)(ErtsPollSet ps,
 	reset_wakeup_state(ps);
     else {
 	if (erts_smp_atomic32_read_acqb(&ps->timeout) > (erts_aint32_t) msec)
-	    wake_poller(ps, 1);
+	    wake_poller(ps, 1, 0);
 #ifdef ERTS_POLL_COUNT_AVOIDED_WAKEUPS
 	else {
 	    if (ERTS_POLLSET_IS_POLLED(ps))
@@ -2266,10 +2305,8 @@ ERTS_POLL_EXPORT(erts_poll_create_pollset)(void)
     erts_atomic32_init_nob(&ps->polled, 0);
     erts_smp_mtx_init(&ps->mtx, "pollset");
 #endif
-#ifdef ERTS_SMP
+#if defined(USE_THREADS) || ERTS_POLL_ASYNC_INTERRUPT_SUPPORT
     erts_atomic32_init_nob(&ps->wakeup_state, (erts_aint32_t) 0);
-#elif ERTS_POLL_ASYNC_INTERRUPT_SUPPORT
-    ps->wakeup_state = 0;
 #endif
 #if ERTS_POLL_USE_WAKEUP_PIPE
     create_wakeup_pipe(ps);