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-rw-r--r--erts/emulator/beam/erl_db.c43
-rw-r--r--erts/emulator/beam/erl_db.h13
-rw-r--r--erts/emulator/beam/erl_db_hash.c2
-rw-r--r--erts/emulator/beam/erl_init.c41
4 files changed, 92 insertions, 7 deletions
diff --git a/erts/emulator/beam/erl_db.c b/erts/emulator/beam/erl_db.c
index 2e2cb98354..844272c699 100644
--- a/erts/emulator/beam/erl_db.c
+++ b/erts/emulator/beam/erl_db.c
@@ -279,6 +279,8 @@ static ERTS_INLINE void db_init_lock(DbTable* tb, int use_frequent_read_lock,
erts_smp_rwmtx_opt_t rwmtx_opt = ERTS_SMP_RWMTX_OPT_DEFAULT_INITER;
if (use_frequent_read_lock)
rwmtx_opt.type = ERTS_SMP_RWMTX_TYPE_FREQUENT_READ;
+ if (erts_ets_rwmtx_spin_count >= 0)
+ rwmtx_opt.main_spincount = erts_ets_rwmtx_spin_count;
#endif
#ifdef ERTS_SMP
erts_smp_rwmtx_init_opt_x(&tb->common.rwlock, &rwmtx_opt,
@@ -2856,10 +2858,11 @@ BIF_RETTYPE ets_match_spec_run_r_3(BIF_ALIST_3)
** External interface (NOT BIF's)
*/
+int erts_ets_rwmtx_spin_count = -1;
/* Init the db */
-void init_db(void)
+void init_db(ErtsDbSpinCount db_spin_count)
{
DbTable init_tb;
int i;
@@ -2868,10 +2871,48 @@ void init_db(void)
size_t size;
#ifdef ERTS_SMP
+ int max_spin_count = (1 << 15) - 1; /* internal limit */
erts_smp_rwmtx_opt_t rwmtx_opt = ERTS_SMP_RWMTX_OPT_DEFAULT_INITER;
rwmtx_opt.type = ERTS_SMP_RWMTX_TYPE_FREQUENT_READ;
rwmtx_opt.lived = ERTS_SMP_RWMTX_LONG_LIVED;
+ switch (db_spin_count) {
+ case ERTS_DB_SPNCNT_NONE:
+ erts_ets_rwmtx_spin_count = 0;
+ break;
+ case ERTS_DB_SPNCNT_VERY_LOW:
+ erts_ets_rwmtx_spin_count = 100;
+ break;
+ case ERTS_DB_SPNCNT_LOW:
+ erts_ets_rwmtx_spin_count = 200;
+ erts_ets_rwmtx_spin_count += erts_no_schedulers * 50;
+ if (erts_ets_rwmtx_spin_count > 1000)
+ erts_ets_rwmtx_spin_count = 1000;
+ break;
+ case ERTS_DB_SPNCNT_HIGH:
+ erts_ets_rwmtx_spin_count = 2000;
+ erts_ets_rwmtx_spin_count += erts_no_schedulers * 100;
+ if (erts_ets_rwmtx_spin_count > 15000)
+ erts_ets_rwmtx_spin_count = 15000;
+ break;
+ case ERTS_DB_SPNCNT_VERY_HIGH:
+ erts_ets_rwmtx_spin_count = 15000;
+ erts_ets_rwmtx_spin_count += erts_no_schedulers * 500;
+ if (erts_ets_rwmtx_spin_count > max_spin_count)
+ erts_ets_rwmtx_spin_count = max_spin_count;
+ break;
+ case ERTS_DB_SPNCNT_EXTREMELY_HIGH:
+ erts_ets_rwmtx_spin_count = max_spin_count;
+ break;
+ case ERTS_DB_SPNCNT_NORMAL:
+ default:
+ erts_ets_rwmtx_spin_count = -1;
+ break;
+ }
+
+ if (erts_ets_rwmtx_spin_count >= 0)
+ rwmtx_opt.main_spincount = erts_ets_rwmtx_spin_count;
+
meta_main_tab_locks =
erts_alloc_permanent_cache_aligned(ERTS_ALC_T_DB_TABLES,
sizeof(erts_meta_main_tab_lock_t)
diff --git a/erts/emulator/beam/erl_db.h b/erts/emulator/beam/erl_db.h
index 5b4681fc90..5039b71108 100644
--- a/erts/emulator/beam/erl_db.h
+++ b/erts/emulator/beam/erl_db.h
@@ -61,7 +61,17 @@ union db_table {
"ERL_MAX_ETS_TABLES" */
#define ERL_MAX_ETS_TABLES_ENV "ERL_MAX_ETS_TABLES"
-void init_db(void);
+typedef enum {
+ ERTS_DB_SPNCNT_NONE,
+ ERTS_DB_SPNCNT_VERY_LOW,
+ ERTS_DB_SPNCNT_LOW,
+ ERTS_DB_SPNCNT_NORMAL,
+ ERTS_DB_SPNCNT_HIGH,
+ ERTS_DB_SPNCNT_VERY_HIGH,
+ ERTS_DB_SPNCNT_EXTREMELY_HIGH
+} ErtsDbSpinCount;
+
+void init_db(ErtsDbSpinCount);
int erts_db_process_exiting(Process *, ErtsProcLocks);
void db_info(int, void *, int);
void erts_db_foreach_table(void (*)(DbTable *, void *), void *);
@@ -69,6 +79,7 @@ void erts_db_foreach_offheap(DbTable *,
void (*func)(ErlOffHeap *, void *),
void *);
+extern int erts_ets_rwmtx_spin_count;
extern int user_requested_db_max_tabs; /* set in erl_init */
extern int erts_ets_realloc_always_moves; /* set in erl_init */
extern int erts_ets_always_compress; /* set in erl_init */
diff --git a/erts/emulator/beam/erl_db_hash.c b/erts/emulator/beam/erl_db_hash.c
index 6e50e9c5b4..dce0a3d621 100644
--- a/erts/emulator/beam/erl_db_hash.c
+++ b/erts/emulator/beam/erl_db_hash.c
@@ -670,6 +670,8 @@ int db_create_hash(Process *p, DbTable *tbl)
int i;
if (tb->common.type & DB_FREQ_READ)
rwmtx_opt.type = ERTS_SMP_RWMTX_TYPE_FREQUENT_READ;
+ if (erts_ets_rwmtx_spin_count >= 0)
+ rwmtx_opt.main_spincount = erts_ets_rwmtx_spin_count;
tb->locks = (DbTableHashFineLocks*) erts_db_alloc_fnf(ERTS_ALC_T_DB_SEG, /* Other type maybe? */
(DbTable *) tb,
sizeof(DbTableHashFineLocks));
diff --git a/erts/emulator/beam/erl_init.c b/erts/emulator/beam/erl_init.c
index 0febe8fb3d..ac1f00d2d8 100644
--- a/erts/emulator/beam/erl_init.c
+++ b/erts/emulator/beam/erl_init.c
@@ -142,7 +142,8 @@ static void erl_init(int ncpu,
int legacy_port_tab,
int time_correction,
ErtsTimeWarpMode time_warp_mode,
- int node_tab_delete_delay);
+ int node_tab_delete_delay,
+ ErtsDbSpinCount db_spin_count);
static erts_atomic_t exiting;
@@ -316,7 +317,8 @@ erts_short_init(void)
0,
time_correction,
time_warp_mode,
- ERTS_NODE_TAB_DELAY_GC_DEFAULT);
+ ERTS_NODE_TAB_DELAY_GC_DEFAULT,
+ ERTS_DB_SPNCNT_NORMAL);
erts_initialized = 1;
}
@@ -329,7 +331,8 @@ erl_init(int ncpu,
int legacy_port_tab,
int time_correction,
ErtsTimeWarpMode time_warp_mode,
- int node_tab_delete_delay)
+ int node_tab_delete_delay,
+ ErtsDbSpinCount db_spin_count)
{
init_benchmarking();
@@ -369,7 +372,7 @@ erl_init(int ncpu,
erts_ptab_init(); /* Must be after init_emulator() */
erts_init_binary(); /* Must be after init_emulator() */
erts_bp_init();
- init_db(); /* Must be after init_emulator */
+ init_db(db_spin_count); /* Must be after init_emulator */
erts_init_node_tables(node_tab_delete_delay);
init_dist();
erl_drv_thr_init();
@@ -636,6 +639,10 @@ void erts_usage(void)
erts_fprintf(stderr, "-zdntgc time set delayed node table gc in seconds\n");
erts_fprintf(stderr, " valid values are infinity or intergers in the range [0-%d]\n",
ERTS_NODE_TAB_DELAY_GC_MAX);
+#if 0
+ erts_fprintf(stderr, "-zebwt val set ets busy wait threshold, valid values are:\n");
+ erts_fprintf(stderr, " none|very_short|short|medium|long|very_long|extremely_long\n");
+#endif
erts_fprintf(stderr, "\n");
erts_fprintf(stderr, "Note that if the emulator is started with erlexec (typically\n");
erts_fprintf(stderr, "from the erl script), these flags should be specified with +.\n");
@@ -1227,6 +1234,7 @@ erl_start(int argc, char **argv)
int time_correction;
ErtsTimeWarpMode time_warp_mode;
int node_tab_delete_delay = ERTS_NODE_TAB_DELAY_GC_DEFAULT;
+ ErtsDbSpinCount db_spin_count = ERTS_DB_SPNCNT_NORMAL;
set_default_time_adj(&time_correction,
&time_warp_mode);
@@ -2042,6 +2050,28 @@ erl_start(int argc, char **argv)
}
}
node_tab_delete_delay = (int) secs;
+ }
+ else if (has_prefix("ebwt", sub_param)) {
+ arg = get_arg(sub_param+4, argv[i+1], &i);
+ if (sys_strcmp(arg, "none") == 0)
+ db_spin_count = ERTS_DB_SPNCNT_NONE;
+ else if (sys_strcmp(arg, "very_short") == 0)
+ db_spin_count = ERTS_DB_SPNCNT_VERY_LOW;
+ else if (sys_strcmp(arg, "short") == 0)
+ db_spin_count = ERTS_DB_SPNCNT_LOW;
+ else if (sys_strcmp(arg, "medium") == 0)
+ db_spin_count = ERTS_DB_SPNCNT_NORMAL;
+ else if (sys_strcmp(arg, "long") == 0)
+ db_spin_count = ERTS_DB_SPNCNT_HIGH;
+ else if (sys_strcmp(arg, "very_long") == 0)
+ db_spin_count = ERTS_DB_SPNCNT_VERY_HIGH;
+ else if (sys_strcmp(arg, "extremely_long") == 0)
+ db_spin_count = ERTS_DB_SPNCNT_EXTREMELY_HIGH;
+ else {
+ erts_fprintf(stderr,
+ "Invalid ets busy wait threshold: %s\n", arg);
+ erts_usage();
+ }
} else {
erts_fprintf(stderr, "bad -z option %s\n", argv[i]);
erts_usage();
@@ -2116,7 +2146,8 @@ erl_start(int argc, char **argv)
legacy_port_tab,
time_correction,
time_warp_mode,
- node_tab_delete_delay);
+ node_tab_delete_delay,
+ db_spin_count);
load_preloaded();
erts_end_staging_code_ix();