Merge branch 'vinoski/ds'

* vinoski/ds:
  initial support for dirty schedulers and dirty NIFs

11 files changed, 1059 insertions, 188 deletions

diff --git a/erts/emulator/beam/beam_emu.c b/erts/emulator/beam/beam_emu.c
index b413f0e859..7fecdd5c5f 100644
--- a/erts/emulator/beam/beam_emu.c
+++ b/erts/emulator/beam/beam_emu.c
@@ -217,6 +217,7 @@ BeamInstr beam_continue_exit[1];
 
 BeamInstr* em_call_error_handler;
 BeamInstr* em_apply_bif;
+BeamInstr* em_call_nif;
 
 
 /* NOTE These should be the only variables containing trace instructions.
@@ -3323,6 +3324,13 @@ void process_main(void)
 		reg[0] = r(0);
 		nif_bif_result = (*fp)(&env, bif_nif_arity, reg);
 		erts_post_nif(&env);
+#ifdef ERTS_DIRTY_SCHEDULERS
+		if (is_non_value(nif_bif_result) && c_p->freason == TRAP) {
+		    Export* ep = (Export*) c_p->psd->data[ERTS_PSD_DIRTY_SCHED_TRAP_EXPORT];
+		    ep->code[0] = I[-3];
+		    ep->code[1] = I[-2];
+		}
+#endif
 	    }
 	    ASSERT(!ERTS_PROC_IS_EXITING(c_p) || is_non_value(nif_bif_result));
 	    PROCESS_MAIN_CHK_LOCKS(c_p);
@@ -4964,6 +4972,7 @@ void process_main(void)
      
      em_call_error_handler = OpCode(call_error_handler);
      em_apply_bif = OpCode(apply_bif);
+     em_call_nif = OpCode(call_nif);
 
      beam_apply[0]             = (BeamInstr) OpCode(i_apply);
      beam_apply[1]             = (BeamInstr) OpCode(normal_exit);
diff --git a/erts/emulator/beam/beam_load.h b/erts/emulator/beam/beam_load.h
index 65a8f26d7c..bd22b0c4de 100644
--- a/erts/emulator/beam/beam_load.h
+++ b/erts/emulator/beam/beam_load.h
@@ -49,6 +49,7 @@ extern void** beam_ops;
 extern BeamInstr beam_debug_apply[];
 extern BeamInstr* em_call_error_handler;
 extern BeamInstr* em_apply_bif;
+extern BeamInstr* em_call_nif;
 
 /*
  * The following variables keep a sorted list of address ranges for
diff --git a/erts/emulator/beam/erl_alloc.c b/erts/emulator/beam/erl_alloc.c
index 8094c6ee2e..c6b324dc15 100644
--- a/erts/emulator/beam/erl_alloc.c
+++ b/erts/emulator/beam/erl_alloc.c
@@ -1754,6 +1754,9 @@ erts_alloc_register_scheduler(void *vesdp)
     int ix = (int) esdp->no;
     int aix;
 
+#ifdef ERTS_DIRTY_SCHEDULERS
+    ASSERT(!ERTS_SCHEDULER_IS_DIRTY(esdp));
+#endif
     for (aix = ERTS_ALC_A_MIN; aix <= ERTS_ALC_A_MAX; aix++) {
 	ErtsAllocatorThrSpec_t *tspec = &erts_allctr_thr_spec[aix];
 	esdp->alloc_data.deallctr[aix] = NULL;
diff --git a/erts/emulator/beam/erl_bif_info.c b/erts/emulator/beam/erl_bif_info.c
index e0b654cb22..f25b4dbae5 100755
--- a/erts/emulator/beam/erl_bif_info.c
+++ b/erts/emulator/beam/erl_bif_info.c
@@ -90,6 +90,9 @@ static char erts_system_version[] = ("Erlang/OTP " ERLANG_OTP_RELEASE
 				     " [smp:%beu:%beu]"
 #endif
 #ifdef USE_THREADS
+#ifdef ERTS_DIRTY_SCHEDULERS
+				     " [ds:%beu:%beu:%beu]"
+#endif
 				     " [async-threads:%d]"
 #endif
 #ifdef HIPE
@@ -312,7 +315,13 @@ erts_print_system_version(int to, void *arg, Process *c_p)
     char *ocp = otp_correction_package;
 #ifdef ERTS_SMP
     Uint total, online, active;
-    (void) erts_schedulers_state(&total, &online, &active, 0);
+#ifdef ERTS_DIRTY_SCHEDULERS
+    Uint dirty_cpu, dirty_cpu_onln, dirty_io;
+
+    (void) erts_schedulers_state(&total, &online, &active, &dirty_cpu, &dirty_cpu_onln, &dirty_io, 0);
+#else
+    (void) erts_schedulers_state(&total, &online, &active, NULL, NULL, NULL, 0);
+#endif
 #endif
     for (i = 0; i < sizeof(otp_correction_package)-4; i++) {
 	if (ocp[i] == '-' && ocp[i+1] == 'r' && ocp[i+2] == 'c')
@@ -330,6 +339,9 @@ erts_print_system_version(int to, void *arg, Process *c_p)
 		      rc_str
 #ifdef ERTS_SMP
 		      , total, online
+#ifdef ERTS_DIRTY_SCHEDULERS
+		      , dirty_cpu, dirty_cpu_onln, dirty_io
+#endif
 #endif
 #ifdef USE_THREADS
 		      , erts_async_max_threads
@@ -2477,6 +2489,9 @@ BIF_RETTYPE system_info_1(BIF_ALIST_1)
 	switch (erts_schedulers_state(&total,
 				      &online,
 				      &active,
+				      NULL,
+				      NULL,
+				      NULL,
 				      1)) {
 	case ERTS_SCHDLR_SSPND_DONE: {
 	    Eterm *hp = HAlloc(BIF_P, 4);
@@ -2500,7 +2515,7 @@ BIF_RETTYPE system_info_1(BIF_ALIST_1)
 	BIF_RET(make_small(1));
 #else
 	Uint total, online, active;
-	switch (erts_schedulers_state(&total, &online, &active, 1)) {
+	switch (erts_schedulers_state(&total, &online, &active, NULL, NULL, NULL, 1)) {
 	case ERTS_SCHDLR_SSPND_DONE:
 	    BIF_RET(make_small(online));
 	case ERTS_SCHDLR_SSPND_YIELD_RESTART:
@@ -2517,7 +2532,7 @@ BIF_RETTYPE system_info_1(BIF_ALIST_1)
 	BIF_RET(make_small(1));
 #else
 	Uint total, online, active;
-	switch (erts_schedulers_state(&total, &online, &active, 1)) {
+	switch (erts_schedulers_state(&total, &online, &active, NULL, NULL, NULL, 1)) {
 	case ERTS_SCHDLR_SSPND_DONE:
 	    BIF_RET(make_small(active));
 	case ERTS_SCHDLR_SSPND_YIELD_RESTART:
@@ -2529,6 +2544,20 @@ BIF_RETTYPE system_info_1(BIF_ALIST_1)
 	    BIF_ERROR(BIF_P, EXC_INTERNAL_ERROR);
 	}
 #endif
+#if defined(ERTS_SMP) && defined(ERTS_DIRTY_SCHEDULERS)
+    } else if (ERTS_IS_ATOM_STR("dirty_cpu_schedulers", BIF_ARG_1)) {
+	Uint dirty_cpu;
+	erts_schedulers_state(NULL, NULL, NULL, &dirty_cpu, NULL, NULL, 1);
+	BIF_RET(make_small(dirty_cpu));
+    } else if (ERTS_IS_ATOM_STR("dirty_cpu_schedulers_online", BIF_ARG_1)) {
+	Uint dirty_cpu_onln;
+	erts_schedulers_state(NULL, NULL, NULL, NULL, &dirty_cpu_onln, NULL, 1);
+	BIF_RET(make_small(dirty_cpu_onln));
+    } else if (ERTS_IS_ATOM_STR("dirty_io_schedulers", BIF_ARG_1)) {
+	Uint dirty_io;
+	erts_schedulers_state(NULL, NULL, NULL, NULL, NULL, &dirty_io, 1);
+	BIF_RET(make_small(dirty_io));
+#endif
     } else if (ERTS_IS_ATOM_STR("run_queues", BIF_ARG_1)) {
 	res = make_small(erts_no_run_queues);
 	BIF_RET(res);
diff --git a/erts/emulator/beam/erl_init.c b/erts/emulator/beam/erl_init.c
index 19088fd913..c17256f466 100644
--- a/erts/emulator/beam/erl_init.c
+++ b/erts/emulator/beam/erl_init.c
@@ -484,98 +484,107 @@ void erts_usage(void)
 
     /*    erts_fprintf(stderr, "-# number  set the number of items to be used in traces etc\n"); */
 
-    erts_fprintf(stderr, "-a size     suggested stack size in kilo words for threads\n");
-    erts_fprintf(stderr, "            in the async-thread pool, valid range is [%d-%d]\n",
+    erts_fprintf(stderr, "-a size        suggested stack size in kilo words for threads\n");
+    erts_fprintf(stderr, "               in the async-thread pool, valid range is [%d-%d]\n",
 		 ERTS_ASYNC_THREAD_MIN_STACK_SIZE,
 		 ERTS_ASYNC_THREAD_MAX_STACK_SIZE);
-    erts_fprintf(stderr, "-A number   set number of threads in async thread pool,\n");
-    erts_fprintf(stderr, "            valid range is [0-%d]\n",
+    erts_fprintf(stderr, "-A number      set number of threads in async thread pool,\n");
+    erts_fprintf(stderr, "               valid range is [0-%d]\n",
 		 ERTS_MAX_NO_OF_ASYNC_THREADS);
 
-    erts_fprintf(stderr, "-B[c|d|i]   c to have Ctrl-c interrupt the Erlang shell,\n");
-    erts_fprintf(stderr, "            d (or no extra option) to disable the break\n");
-    erts_fprintf(stderr, "            handler, i to ignore break signals\n");
+    erts_fprintf(stderr, "-B[c|d|i]      c to have Ctrl-c interrupt the Erlang shell,\n");
+    erts_fprintf(stderr, "               d (or no extra option) to disable the break\n");
+    erts_fprintf(stderr, "               handler, i to ignore break signals\n");
 
     /*    erts_fprintf(stderr, "-b func    set the boot function (default boot)\n"); */
 
-    erts_fprintf(stderr, "-c          disable continuous date/time correction with\n");
-    erts_fprintf(stderr, "            respect to uptime\n");
+    erts_fprintf(stderr, "-c             disable continuous date/time correction with\n");
+    erts_fprintf(stderr, "               respect to uptime\n");
 
-    erts_fprintf(stderr, "-d          don't write a crash dump for internally detected errors\n");
-    erts_fprintf(stderr, "            (halt(String) will still produce a crash dump)\n");
-    erts_fprintf(stderr, "-fn[u|a|l]  Control how filenames are interpreted\n");
-    erts_fprintf(stderr, "-hms size   set minimum heap size in words (default %d)\n",
+    erts_fprintf(stderr, "-d             don't write a crash dump for internally detected errors\n");
+    erts_fprintf(stderr, "               (halt(String) will still produce a crash dump)\n");
+    erts_fprintf(stderr, "-fn[u|a|l]     Control how filenames are interpreted\n");
+    erts_fprintf(stderr, "-hms size      set minimum heap size in words (default %d)\n",
 	       H_DEFAULT_SIZE);
-    erts_fprintf(stderr, "-hmbs size  set minimum binary virtual heap size in words (default %d)\n",
+    erts_fprintf(stderr, "-hmbs size     set minimum binary virtual heap size in words (default %d)\n",
 	       VH_DEFAULT_SIZE);
 
     /*    erts_fprintf(stderr, "-i module  set the boot module (default init)\n"); */
 
-    erts_fprintf(stderr, "-K boolean  enable or disable kernel poll\n");
-    erts_fprintf(stderr, "-n[s|a|d]   Control behavior of signals to ports\n");
-    erts_fprintf(stderr, "            Note that this flag is deprecated!\n");
-    erts_fprintf(stderr, "-M<X> <Y>   memory allocator switches,\n");
-    erts_fprintf(stderr, "            see the erts_alloc(3) documentation for more info.\n");
-    erts_fprintf(stderr, "-pc <set>   Control what characters are considered printable (default latin1)\n");
-    erts_fprintf(stderr, "-P number   set maximum number of processes on this node,\n");
-    erts_fprintf(stderr, "            valid range is [%d-%d]\n",
+    erts_fprintf(stderr, "-K boolean     enable or disable kernel poll\n");
+    erts_fprintf(stderr, "-n[s|a|d]      Control behavior of signals to ports\n");
+    erts_fprintf(stderr, "               Note that this flag is deprecated!\n");
+    erts_fprintf(stderr, "-M<X> <Y>      memory allocator switches,\n");
+    erts_fprintf(stderr, "               see the erts_alloc(3) documentation for more info.\n");
+    erts_fprintf(stderr, "-pc <set>      Control what characters are considered printable (default latin1)\n");
+    erts_fprintf(stderr, "-P number      set maximum number of processes on this node,\n");
+    erts_fprintf(stderr, "               valid range is [%d-%d]\n",
 		 ERTS_MIN_PROCESSES, ERTS_MAX_PROCESSES);
-    erts_fprintf(stderr, "-Q number   set maximum number of ports on this node,\n");
-    erts_fprintf(stderr, "            valid range is [%d-%d]\n",
+    erts_fprintf(stderr, "-Q number      set maximum number of ports on this node,\n");
+    erts_fprintf(stderr, "               valid range is [%d-%d]\n",
 		 ERTS_MIN_PORTS, ERTS_MAX_PORTS);
-    erts_fprintf(stderr, "-R number   set compatibility release number,\n");
-    erts_fprintf(stderr, "            valid range [%d-%d]\n",
+    erts_fprintf(stderr, "-R number      set compatibility release number,\n");
+    erts_fprintf(stderr, "               valid range [%d-%d]\n",
 		 this_rel-2, this_rel);
 
-    erts_fprintf(stderr, "-r          force ets memory block to be moved on realloc\n");
-    erts_fprintf(stderr, "-rg amount  set reader groups limit\n");
-    erts_fprintf(stderr, "-sbt type   set scheduler bind type, valid types are:\n");
-    erts_fprintf(stderr, "-stbt type  u|ns|ts|ps|s|nnts|nnps|tnnps|db\n");
-    erts_fprintf(stderr, "-sbwt val   set scheduler busy wait threshold, valid values are:\n");
-    erts_fprintf(stderr, "            none|very_short|short|medium|long|very_long.\n");
-    erts_fprintf(stderr, "-scl bool   enable/disable compaction of scheduler load,\n");
-    erts_fprintf(stderr, "            see the erl(1) documentation for more info.\n");
-    erts_fprintf(stderr, "-sct cput   set cpu topology,\n");
-    erts_fprintf(stderr, "            see the erl(1) documentation for more info.\n");
+    erts_fprintf(stderr, "-r             force ets memory block to be moved on realloc\n");
+    erts_fprintf(stderr, "-rg amount     set reader groups limit\n");
+    erts_fprintf(stderr, "-sbt type      set scheduler bind type, valid types are:\n");
+    erts_fprintf(stderr, "-stbt type     u|ns|ts|ps|s|nnts|nnps|tnnps|db\n");
+    erts_fprintf(stderr, "-sbwt val      set scheduler busy wait threshold, valid values are:\n");
+    erts_fprintf(stderr, "               none|very_short|short|medium|long|very_long.\n");
+    erts_fprintf(stderr, "-scl bool      enable/disable compaction of scheduler load,\n");
+    erts_fprintf(stderr, "               see the erl(1) documentation for more info.\n");
+    erts_fprintf(stderr, "-sct cput      set cpu topology,\n");
+    erts_fprintf(stderr, "               see the erl(1) documentation for more info.\n");
 #if ERTS_HAVE_SCHED_UTIL_BALANCING_SUPPORT_OPT
-    erts_fprintf(stderr, "-sub bool   enable/disable scheduler utilization balancing,\n");
+    erts_fprintf(stderr, "-sub bool      enable/disable scheduler utilization balancing,\n");
 #else
-    erts_fprintf(stderr, "-sub false  disable scheduler utilization balancing,\n");
+    erts_fprintf(stderr, "-sub false     disable scheduler utilization balancing,\n");
 #endif
-    erts_fprintf(stderr, "            see the erl(1) documentation for more info.\n");
-    erts_fprintf(stderr, "-sws val    set scheduler wakeup strategy, valid values are:\n");
-    erts_fprintf(stderr, "            default|legacy.\n");
-    erts_fprintf(stderr, "-swct val   set scheduler wake cleanup threshold, valid values are:\n");
-    erts_fprintf(stderr, "            very_lazy|lazy|medium|eager|very_eager.\n");
-    erts_fprintf(stderr, "-swt val    set scheduler wakeup threshold, valid values are:\n");
-    erts_fprintf(stderr, "            very_low|low|medium|high|very_high.\n");
-    erts_fprintf(stderr, "-sss size   suggested stack size in kilo words for scheduler threads,\n");
-    erts_fprintf(stderr, "            valid range is [%d-%d]\n",
+    erts_fprintf(stderr, "               see the erl(1) documentation for more info.\n");
+    erts_fprintf(stderr, "-sws val       set scheduler wakeup strategy, valid values are:\n");
+    erts_fprintf(stderr, "               default|legacy.\n");
+    erts_fprintf(stderr, "-swct val      set scheduler wake cleanup threshold, valid values are:\n");
+    erts_fprintf(stderr, "               very_lazy|lazy|medium|eager|very_eager.\n");
+    erts_fprintf(stderr, "-swt val       set scheduler wakeup threshold, valid values are:\n");
+    erts_fprintf(stderr, "               very_low|low|medium|high|very_high.\n");
+    erts_fprintf(stderr, "-sss size      suggested stack size in kilo words for scheduler threads,\n");
+    erts_fprintf(stderr, "               valid range is [%d-%d]\n",
 		 ERTS_SCHED_THREAD_MIN_STACK_SIZE,
 		 ERTS_SCHED_THREAD_MAX_STACK_SIZE);
-    erts_fprintf(stderr, "-spp Bool   set port parallelism scheduling hint\n");
-    erts_fprintf(stderr, "-S n1:n2    set number of schedulers (n1), and number of\n");
-    erts_fprintf(stderr, "            schedulers online (n2), maximum for both\n");
-    erts_fprintf(stderr, "            numbers is %d\n",
+    erts_fprintf(stderr, "-spp Bool      set port parallelism scheduling hint\n");
+    erts_fprintf(stderr, "-S n1:n2       set number of schedulers (n1), and number of\n");
+    erts_fprintf(stderr, "               schedulers online (n2), maximum for both\n");
+    erts_fprintf(stderr, "               numbers is %d\n",
 		 ERTS_MAX_NO_OF_SCHEDULERS);
-    erts_fprintf(stderr, "-SP p1:p2   specify schedulers (p1) and schedulers online (p2)\n");
-    erts_fprintf(stderr, "            as percentages of logical processors configured and logical\n");
-    erts_fprintf(stderr, "            processors available, respectively\n");
-    erts_fprintf(stderr, "-t size     set the maximum number of atoms the "
-			 "emulator can handle\n");
-    erts_fprintf(stderr, "            valid range is [%d-%d]\n",
+    erts_fprintf(stderr, "-SP p1:p2      specify schedulers (p1) and schedulers online (p2)\n");
+    erts_fprintf(stderr, "               as percentages of logical processors configured and logical\n");
+    erts_fprintf(stderr, "               processors available, respectively\n");
+#ifdef ERTS_DIRTY_SCHEDULERS
+    erts_fprintf(stderr, "-SDcpu n1:n2   set number of dirty CPU schedulers (n1), and number of\n");
+    erts_fprintf(stderr, "               dirty CPU schedulers online (n2), valid range for both\n");
+    erts_fprintf(stderr, "               numbers is [1-%d], and n2 must be less than or equal to n1\n",
+		 ERTS_MAX_NO_OF_DIRTY_CPU_SCHEDULERS);
+    erts_fprintf(stderr, "-SDPcpu p1:p2  specify dirty CPU schedulers (p1) and dirty CPU schedulers\n");
+    erts_fprintf(stderr, "               online (p2) as percentages of logical processors configured\n");
+    erts_fprintf(stderr, "               and logical processors available, respectively\n");
+    erts_fprintf(stderr, "-SDio n        set number of dirty I/O schedulers, valid range is [0-%d]\n",
+		 ERTS_MAX_NO_OF_DIRTY_IO_SCHEDULERS);
+#endif
+    erts_fprintf(stderr, "-t size        set the maximum number of atoms the emulator can handle\n");
+    erts_fprintf(stderr, "               valid range is [%d-%d]\n",
 		 MIN_ATOM_TABLE_SIZE, MAX_ATOM_TABLE_SIZE);
-    erts_fprintf(stderr, "-T number   set modified timing level,\n");
-    erts_fprintf(stderr, "            valid range is [0-%d]\n",
+    erts_fprintf(stderr, "-T number      set modified timing level, valid range is [0-%d]\n",
 		 ERTS_MODIFIED_TIMING_LEVELS-1);
-    erts_fprintf(stderr, "-V          print Erlang version\n");
+    erts_fprintf(stderr, "-V             print Erlang version\n");
 
-    erts_fprintf(stderr, "-v          turn on chatty mode (GCs will be reported etc)\n");
+    erts_fprintf(stderr, "-v             turn on chatty mode (GCs will be reported etc)\n");
 
-    erts_fprintf(stderr, "-W<i|w>     set error logger warnings mapping,\n");
-    erts_fprintf(stderr, "            see error_logger documentation for details\n");
-    erts_fprintf(stderr, "-zdbbl size set the distribution buffer busy limit in kilobytes\n");
-    erts_fprintf(stderr, "            valid range is [1-%d]\n", INT_MAX/1024);
+    erts_fprintf(stderr, "-W<i|w>        set error logger warnings mapping,\n");
+    erts_fprintf(stderr, "               see error_logger documentation for details\n");
+    erts_fprintf(stderr, "-zdbbl size    set the distribution buffer busy limit in kilobytes\n");
+    erts_fprintf(stderr, "               valid range is [1-%d]\n", INT_MAX/1024);
     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");
@@ -643,6 +652,13 @@ early_init(int *argc, char **argv) /*
     int schdlrs_percentage = 100;
     int schdlrs_onln_percentage = 100;
     int max_main_threads;
+#ifdef ERTS_DIRTY_SCHEDULERS
+    int dirty_cpu_scheds;
+    int dirty_cpu_scheds_online;
+    int dirty_cpu_scheds_pctg = 100;
+    int dirty_cpu_scheds_onln_pctg = 100;
+    int dirty_io_scheds;
+#endif
     int max_reader_groups;
     int reader_groups;
     char envbuf[21]; /* enough for any 64-bit integer */
@@ -718,6 +734,12 @@ early_init(int *argc, char **argv) /*
     schdlrs = no_schedulers;
     schdlrs_onln = no_schedulers_online;
 
+#ifdef ERTS_DIRTY_SCHEDULERS
+    dirty_cpu_scheds = no_schedulers;
+    dirty_cpu_scheds_online = no_schedulers_online;
+    dirty_io_scheds = 10;
+#endif
+
     envbufsz = sizeof(envbuf);
 
     /* erts_sys_getenv(_raw)() not initialized yet; need erts_sys_getenv__() */
@@ -808,7 +830,121 @@ early_init(int *argc, char **argv) /*
                         VERBOSE(DEBUG_SYSTEM,
                                 ("using %d:%d scheduler percentages\n",
                                  schdlrs_percentage, schdlrs_onln_percentage));
-                    } else {
+                    }
+#ifdef ERTS_DIRTY_SCHEDULERS
+		    else if (argv[i][2] == 'D') {
+			char *arg;
+			char *type = argv[i]+3;
+			if (strcmp(type, "Pcpu") == 0) {
+			    int ptot, ponln;
+			    arg = get_arg(argv[i]+7, argv[i+1], &i);
+			    switch (sscanf(arg, "%d:%d", &ptot, &ponln)) {
+			    case 0:
+				switch (sscanf(arg, ":%d", &ponln)) {
+				case 1:
+				    if (ponln < 0)
+					goto bad_SDPcpu;
+				    ptot = 100;
+				    goto chk_SDPcpu;
+				default:
+				    goto bad_SDPcpu;
+				}
+			    case 1:
+				if (ptot < 0)
+				    goto bad_SDPcpu;
+				ponln = ptot < 100 ? ptot : 100;
+				goto chk_SDPcpu;
+			    case 2:
+				if (ptot < 0 || ponln < 0)
+				    goto bad_SDPcpu;
+			    chk_SDPcpu:
+				dirty_cpu_scheds_pctg = ptot;
+				dirty_cpu_scheds_onln_pctg = ponln;
+				break;
+			    default:
+			    bad_SDPcpu:
+				erts_fprintf(stderr,
+					     "bad dirty CPU schedulers percentage specifier %s\n",
+					     arg);
+				erts_usage();
+				break;
+			    }
+			    VERBOSE(DEBUG_SYSTEM,
+				    ("using %d:%d dirty CPU scheduler percentages\n",
+				     dirty_cpu_scheds_pctg, dirty_cpu_scheds_onln_pctg));
+			} else if (strcmp(type, "cpu") == 0) {
+			    int tot, onln;
+			    arg = get_arg(argv[i]+6, argv[i+1], &i);
+			    switch (sscanf(arg, "%d:%d", &tot, &onln)) {
+			    case 0:
+				switch (sscanf(arg, ":%d", &onln)) {
+				case 1:
+				    tot = no_schedulers;
+				    goto chk_SDcpu;
+				default:
+				    goto bad_SDcpu;
+				}
+			    case 1:
+				onln = tot < dirty_cpu_scheds_online ?
+				    tot : dirty_cpu_scheds_online;
+			    case 2:
+			    chk_SDcpu:
+				if (tot > 0)
+				    dirty_cpu_scheds = tot;
+				else
+				    dirty_cpu_scheds = no_schedulers + tot;
+				if (onln > 0)
+				    dirty_cpu_scheds_online = onln;
+				else
+				    dirty_cpu_scheds_online = no_schedulers_online + onln;
+				if (dirty_cpu_scheds < 1 ||
+				    ERTS_MAX_NO_OF_DIRTY_CPU_SCHEDULERS < dirty_cpu_scheds) {
+				    erts_fprintf(stderr,
+						 "bad amount of dirty CPU schedulers %d\n",
+						 tot);
+				    erts_usage();
+				}
+				if (dirty_cpu_scheds_online < 1 ||
+				    dirty_cpu_scheds < dirty_cpu_scheds_online) {
+				    erts_fprintf(stderr,
+						 "bad amount of dirty CPU schedulers online %d "
+						 "(total amount of dirty CPU schedulers %d)\n",
+						 dirty_cpu_scheds_online, dirty_cpu_scheds);
+				    erts_usage();
+				}
+				break;
+			    default:
+			    bad_SDcpu:
+				erts_fprintf(stderr,
+					     "bad amount of dirty CPU schedulers %s\n",
+					     arg);
+				erts_usage();
+				break;
+			    }
+			    VERBOSE(DEBUG_SYSTEM,
+				    ("using %d:%d dirty CPU scheduler(s)\n", tot, onln));
+			} else if (strcmp(type, "io") == 0) {
+			    arg = get_arg(argv[i]+5, argv[i+1], &i);
+			    dirty_io_scheds = atoi(arg);
+			    if (dirty_io_scheds < 0 ||
+				dirty_io_scheds > ERTS_MAX_NO_OF_DIRTY_IO_SCHEDULERS) {
+				erts_fprintf(stderr,
+					     "bad number of dirty I/O schedulers %s\n",
+					     arg);
+				erts_usage();
+			    }
+			    VERBOSE(DEBUG_SYSTEM,
+				    ("using %d dirty I/O scheduler(s)\n", dirty_io_scheds));
+			} else {
+			    erts_fprintf(stderr,
+					 "bad or missing dirty scheduler specifier: %s\n",
+					 argv[i]);
+			    erts_usage();
+			    break;
+			}
+		    }
+#endif
+		    else {
 			int tot, onln;
 			char *arg = get_arg(argv[i]+2, argv[i+1], &i);
 			switch (sscanf(arg, "%d:%d", &tot, &onln)) {
@@ -895,6 +1031,17 @@ early_init(int *argc, char **argv) /*
 	(void)schdlrs_percentage;
 	(void)schdlrs_onln_percentage;
 #endif
+#ifdef ERTS_DIRTY_SCHEDULERS
+	/* apply any dirty scheduler precentages */
+	if (dirty_cpu_scheds_pctg != 100 || dirty_cpu_scheds_onln_pctg != 100) {
+	    dirty_cpu_scheds = dirty_cpu_scheds * dirty_cpu_scheds_pctg / 100;
+	    dirty_cpu_scheds_online = dirty_cpu_scheds_online * dirty_cpu_scheds_onln_pctg / 100;
+	}
+	if (dirty_cpu_scheds > schdlrs)
+	    dirty_cpu_scheds = schdlrs;
+	if (dirty_cpu_scheds_online > schdlrs_onln)
+	    dirty_cpu_scheds_online = schdlrs_onln;
+#endif
     }
 
 #ifndef USE_THREADS
@@ -907,6 +1054,11 @@ early_init(int *argc, char **argv) /*
 
     erts_no_schedulers = (Uint) no_schedulers;
 #endif
+#ifdef ERTS_DIRTY_SCHEDULERS
+    erts_no_dirty_cpu_schedulers = dirty_cpu_scheds;
+    erts_no_dirty_cpu_schedulers_online = dirty_cpu_scheds_online;
+    erts_no_dirty_io_schedulers = dirty_io_scheds;
+#endif
     erts_early_init_scheduling(no_schedulers);
 
     alloc_opts.ncpu = ncpu;
@@ -924,10 +1076,18 @@ early_init(int *argc, char **argv) /*
      *
      * * Unmanaged threads that need to register:
      * ** Async threads (see erl_async.c)
+     * ** Dirty scheduler threads
      */
     erts_thr_progress_init(no_schedulers,
 			   no_schedulers+2,
-			   erts_async_max_threads);
+#ifndef ERTS_DIRTY_SCHEDULERS
+			   erts_async_max_threads
+#else
+			   erts_async_max_threads +
+			   erts_no_dirty_cpu_schedulers +
+			   erts_no_dirty_io_schedulers
+#endif
+			   );
 #endif
     erts_thr_q_init();
     erts_init_utils();
@@ -1392,7 +1552,15 @@ erl_start(int argc, char **argv)
 	    break;
 
 	case 'S' : /* Was handled in early_init() just read past it */
-	    if (argv[i][2] == 'P')
+	    if (argv[i][2] == 'D') {
+		char* type = argv[i]+3;
+		if (strcmp(type, "Pcpu") == 0)
+		    (void) get_arg(argv[i]+7, argv[i+1], &i);
+		if (strcmp(type, "cpu") == 0)
+		    (void) get_arg(argv[i]+6, argv[i+1], &i);
+		else if (strcmp(type, "io") == 0)
+		    (void) get_arg(argv[i]+5, argv[i+1], &i);
+	    } else if (argv[i][2] == 'P')
 		(void) get_arg(argv[i]+3, argv[i+1], &i);
 	    else
 		(void) get_arg(argv[i]+2, argv[i+1], &i);
diff --git a/erts/emulator/beam/erl_lock_check.c b/erts/emulator/beam/erl_lock_check.c
index 0dd83fa6ed..a8ff94ac89 100644
--- a/erts/emulator/beam/erl_lock_check.c
+++ b/erts/emulator/beam/erl_lock_check.c
@@ -123,6 +123,9 @@ static erts_lc_lock_order_t erts_lock_order[] = {
     {	"schdlr_sspnd",				NULL			},
     {	"migration_info_update",		NULL			},
     {	"run_queue",				"address"		},
+#ifdef ERTS_DIRTY_SCHEDULERS
+    {   "dirty_run_queue_sleep_list",		"address"		},
+#endif
     {	"process_table",			NULL			},
     {	"cpu_info",				NULL			},
     {	"pollset",				"address"		},
diff --git a/erts/emulator/beam/erl_nif.c b/erts/emulator/beam/erl_nif.c
index dc285b3cf7..e1e213c4eb 100644
--- a/erts/emulator/beam/erl_nif.c
+++ b/erts/emulator/beam/erl_nif.c
@@ -34,6 +34,7 @@
 #include "beam_bp.h"
 #include "erl_thr_progress.h"
 #include "dtrace-wrapper.h"
+#include "erl_process.h"
 #if defined(USE_DYNAMIC_TRACE) && (defined(USE_DTRACE) || defined(USE_SYSTEMTAP))
 #define HAVE_USE_DTRACE 1
 #endif
@@ -1451,6 +1452,156 @@ int enif_consume_timeslice(ErlNifEnv* env, int percent)
     return ERTS_BIF_REDS_LEFT(env->proc) == 0;
 }
 
+#ifdef ERTS_DIRTY_SCHEDULERS
+
+static void
+alloc_proc_psd(Process* proc, Export **ep)
+{
+    int i;
+    if (!*ep) {
+	*ep = erts_alloc(ERTS_ALC_T_PSD, sizeof(Export));
+	sys_memset((void*) *ep, 0, sizeof(Export));
+	for (i=0; i<ERTS_NUM_CODE_IX; i++) {
+	    (*ep)->addressv[i] = &(*ep)->code[3];
+	}
+	(*ep)->code[3] = (BeamInstr) em_call_nif;
+    }
+    (void) ERTS_PROC_SET_DIRTY_SCHED_TRAP_EXPORT(proc, ERTS_PROC_LOCK_MAIN, *ep);
+}
+
+static ERL_NIF_TERM
+execute_dirty_nif_finalizer(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[])
+{
+    Eterm* reg = ERTS_PROC_GET_SCHDATA(env->proc)->x_reg_array;
+    ERL_NIF_TERM result = (ERL_NIF_TERM) reg[0];
+    typedef ERL_NIF_TERM (*FinalizerFP)(ErlNifEnv*, ERL_NIF_TERM);
+    FinalizerFP fp;
+#if HAVE_INT64 && SIZEOF_LONG != 8
+    ASSERT(sizeof(fp) <= sizeof(ErlNifUInt64));
+    enif_get_uint64(env, reg[1], (ErlNifUInt64 *) &fp);
+#else
+    ASSERT(sizeof(fp) <= sizeof(unsigned long));
+    enif_get_ulong(env, reg[1], (unsigned long *) &fp);
+#endif
+    return (*fp)(env, result);
+}
+
+#endif /* ERTS_DIRTY_SCHEDULERS */
+
+#ifdef ERL_NIF_DIRTY_SCHEDULER_SUPPORT
+
+ERL_NIF_TERM
+enif_schedule_dirty_nif(ErlNifEnv* env, int flags,
+			ERL_NIF_TERM (*fp)(ErlNifEnv*, int, const ERL_NIF_TERM[]),
+			int argc, const ERL_NIF_TERM argv[])
+{
+#ifdef USE_THREADS
+    erts_aint32_t state, n, a;
+    Process* proc = env->proc;
+    Eterm* reg = ERTS_PROC_GET_SCHDATA(proc)->x_reg_array;
+    Export* ep = NULL;
+    int i;
+
+    int chkflgs = (flags & (ERL_NIF_DIRTY_JOB_IO_BOUND|ERL_NIF_DIRTY_JOB_CPU_BOUND));
+    if (chkflgs != ERL_NIF_DIRTY_JOB_IO_BOUND && chkflgs != ERL_NIF_DIRTY_JOB_CPU_BOUND)
+	return enif_make_badarg(env);
+
+    a = erts_smp_atomic32_read_acqb(&proc->state);
+    while (1) {
+	n = state = a;
+	if (chkflgs == ERL_NIF_DIRTY_JOB_CPU_BOUND)
+	    n |= ERTS_PSFLG_DIRTY_CPU_PROC;
+	else
+	    n |= ERTS_PSFLG_DIRTY_IO_PROC;
+	a = erts_smp_atomic32_cmpxchg_mb(&proc->state, n, state);
+	if (a == state)
+	    break;
+    }
+    if (!(ep = ERTS_PROC_GET_DIRTY_SCHED_TRAP_EXPORT(proc)))
+	alloc_proc_psd(proc, &ep);
+    ERTS_VBUMP_ALL_REDS(proc);
+    ep->code[2] = argc;
+    for (i = 0; i < argc; i++) {
+	reg[i] = (Eterm) argv[i];
+    }
+    proc->i = (BeamInstr*) ep->addressv[0];
+    ep->code[4] = (BeamInstr) fp;
+    proc->freason = TRAP;
+
+    return THE_NON_VALUE;
+#else
+    return (*fp)(env, argc, argv);
+#endif
+}
+
+ERL_NIF_TERM
+enif_schedule_dirty_nif_finalizer(ErlNifEnv* env, ERL_NIF_TERM result,
+				  ERL_NIF_TERM (*fp)(ErlNifEnv*, ERL_NIF_TERM))
+{
+#ifdef USE_THREADS
+    erts_aint32_t state, n, a;
+    Process* proc = env->proc;
+    Eterm* reg = ERTS_PROC_GET_SCHDATA(proc)->x_reg_array;
+    Export* ep;
+
+    a = erts_smp_atomic32_read_acqb(&proc->state);
+    while (1) {
+	n = state = a;
+	if (!(n & (ERTS_PSFLG_DIRTY_CPU_PROC_IN_Q|ERTS_PSFLG_DIRTY_IO_PROC_IN_Q)))
+	    break;
+	n &= ~(ERTS_PSFLG_DIRTY_CPU_PROC|ERTS_PSFLG_DIRTY_IO_PROC
+	       |ERTS_PSFLG_DIRTY_CPU_PROC_IN_Q|ERTS_PSFLG_DIRTY_IO_PROC_IN_Q);
+	a = erts_smp_atomic32_cmpxchg_mb(&proc->state, n, state);
+	if (a == state)
+	    break;
+    }
+    if (!(ep = ERTS_PROC_GET_DIRTY_SCHED_TRAP_EXPORT(proc)))
+	alloc_proc_psd(proc, &ep);
+    ERTS_VBUMP_ALL_REDS(proc);
+    ep->code[2] = 2;
+    reg[0] = (Eterm) result;
+#if HAVE_INT64 && SIZEOF_LONG != 8
+    ASSERT(sizeof(fp) <= sizeof(ErlNifUInt64));
+    reg[1] = (Eterm) enif_make_uint64(env, (ErlNifUInt64) fp);
+#else
+    ASSERT(sizeof(fp) <= sizeof(unsigned long));
+    reg[1] = (Eterm) enif_make_ulong(env, (unsigned long) fp);
+#endif
+    proc->i = (BeamInstr*) ep->addressv[0];
+    ep->code[4] = (BeamInstr) execute_dirty_nif_finalizer;
+    proc->freason = TRAP;
+
+    return THE_NON_VALUE;
+#else
+    return (*fp)(env, result);
+#endif
+}
+
+/* A simple finalizer that just returns its result argument */
+ERL_NIF_TERM
+enif_dirty_nif_finalizer(ErlNifEnv* env, ERL_NIF_TERM result)
+{
+    return result;
+}
+
+int
+enif_is_on_dirty_scheduler(ErlNifEnv* env)
+{
+    return ERTS_SCHEDULER_IS_DIRTY(env->proc->scheduler_data);
+}
+
+int
+enif_have_dirty_schedulers()
+{
+#ifdef USE_THREADS
+    return 1;
+#else
+    return 0;
+#endif
+}
+
+#endif /* ERL_NIF_DIRTY_SCHEDULER_SUPPORT */
+
 /***************************************************************************
  **                              load_nif/2                               **
  ***************************************************************************/
diff --git a/erts/emulator/beam/erl_nif.h b/erts/emulator/beam/erl_nif.h
index 5f4dc21d5c..fb3c359ec9 100644
--- a/erts/emulator/beam/erl_nif.h
+++ b/erts/emulator/beam/erl_nif.h
@@ -23,7 +23,11 @@
 #ifndef __ERL_NIF_H__
 #define __ERL_NIF_H__
 
+#ifdef HAVE_CONFIG_H
+#  include "config.h"
+#endif
 
+#include "erl_native_features_config.h"
 #include "erl_drv_nif.h"
 
 /* Version history:
@@ -34,9 +38,14 @@
 ** 2.2: R14B03 enif_is_exception
 ** 2.3: R15 enif_make_reverse_list, enif_is_number
 ** 2.4: R16 enif_consume_timeslice
+** 2.5: R17 dirty schedulers
 */
 #define ERL_NIF_MAJOR_VERSION 2
+#ifdef ERL_NIF_DIRTY_SCHEDULER_SUPPORT
+#define ERL_NIF_MINOR_VERSION 5
+#else
 #define ERL_NIF_MINOR_VERSION 4
+#endif
 
 #include <stdlib.h>
 
@@ -159,6 +168,14 @@ typedef int ErlNifTSDKey;
 
 typedef ErlDrvThreadOpts ErlNifThreadOpts;
 
+#ifdef ERL_NIF_DIRTY_SCHEDULER_SUPPORT
+typedef enum
+{
+    ERL_NIF_DIRTY_JOB_CPU_BOUND = 1,
+    ERL_NIF_DIRTY_JOB_IO_BOUND  = 2
+}ErlNifDirtyTaskFlags;
+#endif
+
 #if (defined(__WIN32__) || defined(_WIN32) || defined(_WIN32_))
 #  define ERL_NIF_API_FUNC_DECL(RET_TYPE, NAME, ARGS) RET_TYPE (*NAME) ARGS
 typedef struct {
diff --git a/erts/emulator/beam/erl_nif_api_funcs.h b/erts/emulator/beam/erl_nif_api_funcs.h
index 2f841645e1..f5b27dfdfa 100644
--- a/erts/emulator/beam/erl_nif_api_funcs.h
+++ b/erts/emulator/beam/erl_nif_api_funcs.h
@@ -141,6 +141,13 @@ ERL_NIF_API_FUNC_DECL(int,enif_is_number,(ErlNifEnv*, ERL_NIF_TERM term));
 ERL_NIF_API_FUNC_DECL(void*,enif_dlopen,(const char* lib, void (*err_handler)(void*,const char*), void* err_arg));
 ERL_NIF_API_FUNC_DECL(void*,enif_dlsym,(void* handle, const char* symbol, void (*err_handler)(void*,const char*), void* err_arg));
 ERL_NIF_API_FUNC_DECL(int,enif_consume_timeslice,(ErlNifEnv*, int percent));
+#ifdef ERL_NIF_DIRTY_SCHEDULER_SUPPORT
+ERL_NIF_API_FUNC_DECL(ERL_NIF_TERM,enif_schedule_dirty_nif,(ErlNifEnv*,int,ERL_NIF_TERM (*)(ErlNifEnv*,int,const ERL_NIF_TERM[]),int,const ERL_NIF_TERM[]));
+ERL_NIF_API_FUNC_DECL(ERL_NIF_TERM,enif_schedule_dirty_nif_finalizer,(ErlNifEnv*,ERL_NIF_TERM,ERL_NIF_TERM (*)(ErlNifEnv*,ERL_NIF_TERM)));
+ERL_NIF_API_FUNC_DECL(ERL_NIF_TERM,enif_dirty_nif_finalizer,(ErlNifEnv*,ERL_NIF_TERM));
+ERL_NIF_API_FUNC_DECL(int,enif_is_on_dirty_scheduler,(ErlNifEnv*));
+ERL_NIF_API_FUNC_DECL(int,enif_have_dirty_schedulers,(void));
+#endif
 
 /*
 ** Add new entries here to keep compatibility on Windows!!!
@@ -266,6 +273,13 @@ ERL_NIF_API_FUNC_DECL(int,enif_consume_timeslice,(ErlNifEnv*, int percent));
 #  define enif_dlopen ERL_NIF_API_FUNC_MACRO(enif_dlopen)
 #  define enif_dlsym ERL_NIF_API_FUNC_MACRO(enif_dlsym)
 #  define enif_consume_timeslice ERL_NIF_API_FUNC_MACRO(enif_consume_timeslice)
+#ifdef ERL_NIF_DIRTY_SCHEDULER_SUPPORT
+#  define enif_schedule_dirty_nif ERL_NIF_API_FUNC_MACRO(enif_schedule_dirty_nif)
+#  define enif_schedule_dirty_nif_finalizer ERL_NIF_API_FUNC_MACRO(enif_schedule_dirty_nif_finalizer)
+#  define enif_dirty_nif_finalizer ERL_NIF_API_FUNC_MACRO(enif_dirty_nif_finalizer)
+#  define enif_is_on_dirty_scheduler ERL_NIF_API_FUNC_MACRO(enif_is_on_dirty_scheduler)
+#  define enif_have_dirty_schedulers ERL_NIF_API_FUNC_MACRO(enif_have_dirty_schedulers)
+#endif
 
 /*
 ** Add new entries here
diff --git a/erts/emulator/beam/erl_process.c b/erts/emulator/beam/erl_process.c
index 74cd84a998..937881212a 100644
--- a/erts/emulator/beam/erl_process.c
+++ b/erts/emulator/beam/erl_process.c
@@ -146,6 +146,11 @@ extern BeamInstr beam_continue_exit[];
 int erts_sched_compact_load;
 int erts_sched_balance_util = 0;
 Uint erts_no_schedulers;
+#ifdef ERTS_DIRTY_SCHEDULERS
+Uint erts_no_dirty_cpu_schedulers;
+Uint erts_no_dirty_cpu_schedulers_online;
+Uint erts_no_dirty_io_schedulers;
+#endif
 
 #define ERTS_THR_PRGR_LATER_CLEANUP_OP_THRESHOLD_VERY_LAZY		(4*1024*1024)
 #define ERTS_THR_PRGR_LATER_CLEANUP_OP_THRESHOLD_LAZY			(512*1024)
@@ -259,6 +264,10 @@ ErtsAlignedRunQueue *erts_aligned_run_queues;
 Uint erts_no_run_queues;
 
 ErtsAlignedSchedulerData *erts_aligned_scheduler_data;
+#ifdef ERTS_DIRTY_SCHEDULERS
+ErtsAlignedSchedulerData *erts_aligned_dirty_cpu_scheduler_data;
+ErtsAlignedSchedulerData *erts_aligned_dirty_io_scheduler_data;
+#endif
 
 typedef union {
     ErtsSchedulerSleepInfo ssi;
@@ -266,6 +275,12 @@ typedef union {
 } ErtsAlignedSchedulerSleepInfo;
 
 static ErtsAlignedSchedulerSleepInfo *aligned_sched_sleep_info;
+#ifdef ERTS_DIRTY_SCHEDULERS
+#ifdef ERTS_SMP
+static ErtsAlignedSchedulerSleepInfo *aligned_dirty_cpu_sched_sleep_info;
+static ErtsAlignedSchedulerSleepInfo *aligned_dirty_io_sched_sleep_info;
+#endif
+#endif
 
 static Uint last_reductions;
 static Uint last_exact_reductions;
@@ -332,6 +347,16 @@ ERTS_SCHED_PREF_QUICK_ALLOC_IMPL(proclist,
     (ASSERT(-1 <= ((int) (IX))					        \
 		 && ((int) (IX)) < ((int) erts_no_schedulers)),		\
      &aligned_sched_sleep_info[(IX)].ssi)
+#ifdef ERTS_DIRTY_SCHEDULERS
+#define ERTS_DIRTY_CPU_SCHED_SLEEP_INFO_IX(IX)				\
+    (ASSERT(0 <= ((int) (IX))					        \
+	    && ((int) (IX)) < ((int) erts_no_dirty_cpu_schedulers)),	\
+     &aligned_dirty_cpu_sched_sleep_info[(IX)].ssi)
+#define ERTS_DIRTY_IO_SCHED_SLEEP_INFO_IX(IX)				\
+    (ASSERT(0 <= ((int) (IX))					        \
+	    && ((int) (IX)) < ((int) erts_no_dirty_io_schedulers)),	\
+     &aligned_dirty_io_sched_sleep_info[(IX)].ssi)
+#endif
 
 #define ERTS_FOREACH_RUNQ(RQVAR, DO)					\
 do {									\
@@ -519,6 +544,13 @@ erts_pre_init_process(void)
      erts_psd_required_locks[ERTS_PSD_DELAYED_GC_TASK_QS].set_locks
 	 = ERTS_PSD_DELAYED_GC_TASK_QS_SET_LOCKS;
 
+#ifdef ERTS_DIRTY_SCHEDULERS
+     erts_psd_required_locks[ERTS_PSD_DIRTY_SCHED_TRAP_EXPORT].get_locks
+	 = ERTS_PSD_DIRTY_SCHED_TRAP_EXPORT_GET_LOCKS;
+     erts_psd_required_locks[ERTS_PSD_DIRTY_SCHED_TRAP_EXPORT].set_locks
+	 = ERTS_PSD_DIRTY_SCHED_TRAP_EXPORT_SET_LOCKS;
+#endif
+
      /* Check that we have locks for all entries */
      for (ix = 0; ix < ERTS_PSD_SIZE; ix++) {
 	 ERTS_SMP_LC_ASSERT(erts_psd_required_locks[ix].get_locks);
@@ -931,7 +963,9 @@ reply_sched_wall_time(void *vswtrp)
     ErlHeapFragment *bp = NULL;
 
     ASSERT(esdp);
-    
+#ifdef ERTS_DIRTY_SCHEDULERS
+    ASSERT(!ERTS_SCHEDULER_IS_DIRTY(esdp));
+#endif
     if (swtrp->set) {
 	if (!swtrp->enable && esdp->sched_wall_time.enabled) {
 	    esdp->sched_wall_time.need = erts_sched_balance_util;
@@ -1015,6 +1049,9 @@ erts_sched_wall_time_request(Process *c_p, int set, int enable)
 
     if (!set && !esdp->sched_wall_time.enabled)
 	return THE_NON_VALUE;
+#ifdef ERTS_DIRTY_SCHEDULERS
+    ASSERT(!ERTS_SCHEDULER_IS_DIRTY(esdp));
+#endif
 
     swtrp = swtreq_alloc();
     ref = erts_make_ref(c_p);
@@ -1492,6 +1529,9 @@ erts_schedule_multi_misc_aux_work(int ignore_self,
 
     if (ignore_self) {
 	ErtsSchedulerData *esdp = erts_get_scheduler_data();
+#ifdef ERTS_DIRTY_SCHEDULERS
+	ASSERT(!ERTS_SCHEDULER_IS_DIRTY(esdp));
+#endif
 	if (esdp)
 	    self = (int) esdp->no;
     }
@@ -1601,7 +1641,7 @@ void
 erts_alloc_notify_delayed_dealloc(int ix)
 {
     ErtsSchedulerData *esdp = erts_get_scheduler_data();
-    if (esdp)
+    if (esdp && !ERTS_SCHEDULER_IS_DIRTY(esdp))
 	schedule_aux_work_wakeup(&esdp->aux_work_data,
 				 ix,
 				 ERTS_SSI_AUX_WORK_DD);
@@ -1615,6 +1655,10 @@ erts_alloc_ensure_handle_delayed_dealloc_call(int ix)
 {
 #ifdef DEBUG
     ErtsSchedulerData *esdp = erts_get_scheduler_data();
+#ifdef ERTS_DIRTY_SCHEDULERS
+    if (esdp && ERTS_SCHEDULER_IS_DIRTY(esdp))
+	return;
+#endif
     ASSERT(!esdp || ix == (int) esdp->no);
 #endif
     set_aux_work_flags_wakeup_nob(ERTS_SCHED_SLEEP_INFO_IX(ix-1),
@@ -2220,6 +2264,9 @@ static ERTS_INLINE void
 sched_active_sys(Uint no, ErtsRunQueue *rq)
 {
     ERTS_SMP_LC_ASSERT(erts_smp_lc_runq_is_locked(rq));
+#ifdef ERTS_DIRTY_SCHEDULERS
+    ASSERT(!ERTS_RUNQ_IX_IS_DIRTY(rq->ix));
+#endif
     ASSERT(rq->waiting < 0);
     rq->waiting *= -1;
     rq->waiting--;
@@ -2276,6 +2323,9 @@ static ERTS_INLINE void
 sched_change_waiting_sys_to_waiting(Uint no, ErtsRunQueue *rq)
 {
     ERTS_SMP_LC_ASSERT(erts_smp_lc_runq_is_locked(rq));
+#ifdef ERTS_DIRTY_SCHEDULERS
+    ASSERT(!ERTS_RUNQ_IX_IS_DIRTY(rq->ix));
+#endif
     ASSERT(rq->waiting < 0);
     rq->waiting *= -1;
 }
@@ -2291,7 +2341,7 @@ sched_waiting(Uint no, ErtsRunQueue *rq)
     else
 	rq->waiting++;
     rq->woken = 0;
-    if (erts_system_profile_flags.scheduler)
+    if (!ERTS_RUNQ_IX_IS_DIRTY(rq->ix) && erts_system_profile_flags.scheduler)
 	profile_scheduler(make_small(no), am_inactive);
 }
 
@@ -2303,7 +2353,7 @@ sched_active(Uint no, ErtsRunQueue *rq)
 	rq->waiting++;
     else
 	rq->waiting--;
-    if (erts_system_profile_flags.scheduler)
+    if (!ERTS_RUNQ_IX_IS_DIRTY(rq->ix) && erts_system_profile_flags.scheduler)
 	profile_scheduler(make_small(no), am_active);
 }
 
@@ -2317,7 +2367,7 @@ ongoing_multi_scheduling_block(void)
 static ERTS_INLINE void
 empty_runq_aux(ErtsRunQueue *rq, Uint32 old_flags)
 {
-    if (old_flags & ERTS_RUNQ_FLG_NONEMPTY) {
+    if (!ERTS_RUNQ_IX_IS_DIRTY(rq->ix) && old_flags & ERTS_RUNQ_FLG_NONEMPTY) {
 #ifdef DEBUG
 	erts_aint32_t empty = erts_smp_atomic32_read_nob(&no_empty_run_queues);
 	/*
@@ -2357,7 +2407,7 @@ static ERTS_INLINE void
 non_empty_runq(ErtsRunQueue *rq)
 {
     Uint32 old_flags = ERTS_RUNQ_FLGS_SET(rq, ERTS_RUNQ_FLG_NONEMPTY);
-    if (!(old_flags & ERTS_RUNQ_FLG_NONEMPTY)) {
+    if (!ERTS_RUNQ_IX_IS_DIRTY(rq->ix) && (!(old_flags & ERTS_RUNQ_FLG_NONEMPTY))) {
 #ifdef DEBUG
 	erts_aint32_t empty = erts_smp_atomic32_read_nob(&no_empty_run_queues);
 	/*
@@ -2602,18 +2652,37 @@ scheduler_wait(int *fcalls, ErtsSchedulerData *esdp, ErtsRunQueue *rq)
 
     ERTS_SMP_LC_ASSERT(erts_smp_lc_runq_is_locked(rq));
 
+#ifdef ERTS_DIRTY_SCHEDULERS
+    if (ERTS_RUNQ_IX_IS_DIRTY(rq->ix))
+	erts_smp_spin_lock(&rq->sleepers.lock);
+#endif
     flgs = sched_prep_spin_wait(ssi);
     if (flgs & ERTS_SSI_FLG_SUSPENDED) {
 	/* Go suspend instead... */
+#ifdef ERTS_DIRTY_SCHEDULERS
+	if (ERTS_RUNQ_IX_IS_DIRTY(rq->ix))
+	    erts_smp_spin_unlock(&rq->sleepers.lock);
+#endif
 	return;
     }
 
+#ifdef ERTS_DIRTY_SCHEDULERS
+    if (ERTS_RUNQ_IX_IS_DIRTY(rq->ix)) {
+	ssi->prev = NULL;
+	ssi->next = rq->sleepers.list;
+	if (rq->sleepers.list)
+	    rq->sleepers.list->prev = ssi;
+	rq->sleepers.list = ssi;
+	erts_smp_spin_unlock(&rq->sleepers.lock);
+    }
+#endif
+
     /*
      * If all schedulers are waiting, one of them *should*
      * be waiting in erl_sys_schedule()
      */
 
-    if (!prepare_for_sys_schedule()) {
+    if (ERTS_SCHEDULER_IS_DIRTY(esdp) || !prepare_for_sys_schedule()) {
 
 	sched_waiting(esdp->no, rq);
 
@@ -2623,12 +2692,13 @@ scheduler_wait(int *fcalls, ErtsSchedulerData *esdp, ErtsRunQueue *rq)
 
     tse_wait:
 
-	if (thr_prgr_active != working)
+	if (!ERTS_SCHEDULER_IS_DIRTY(esdp) && thr_prgr_active != working)
 	    sched_wall_time_change(esdp, thr_prgr_active);
 
 	while (1) {
 
-	    aux_work = erts_atomic32_read_acqb(&ssi->aux_work);
+	    aux_work = ERTS_SCHEDULER_IS_DIRTY(esdp) ? 0 :
+		erts_atomic32_read_acqb(&ssi->aux_work);
 	    if (aux_work) {
 		if (!thr_prgr_active) {
 		    erts_thr_progress_active(esdp, thr_prgr_active = 1);
@@ -2642,11 +2712,13 @@ scheduler_wait(int *fcalls, ErtsSchedulerData *esdp, ErtsRunQueue *rq)
 	    if (aux_work)
 		flgs = erts_smp_atomic32_read_acqb(&ssi->flags);
 	    else {
-		if (thr_prgr_active) {
-		    erts_thr_progress_active(esdp, thr_prgr_active = 0);
-		    sched_wall_time_change(esdp, 0);
+		if (!ERTS_SCHEDULER_IS_DIRTY(esdp)) {
+		    if (thr_prgr_active) {
+			erts_thr_progress_active(esdp, thr_prgr_active = 0);
+			sched_wall_time_change(esdp, 0);
+		    }
+		    erts_thr_progress_prepare_wait(esdp);
 		}
-		erts_thr_progress_prepare_wait(esdp);
 
 		flgs = sched_spin_wait(ssi, spincount);
 		if (flgs & ERTS_SSI_FLG_SLEEPING) {
@@ -2661,7 +2733,8 @@ scheduler_wait(int *fcalls, ErtsSchedulerData *esdp, ErtsRunQueue *rq)
 			} while (res == EINTR);
 		    }
 		}
-		erts_thr_progress_finalize_wait(esdp);
+		if (!ERTS_SCHEDULER_IS_DIRTY(esdp))
+		    erts_thr_progress_finalize_wait(esdp);
 	    }
 
 	    if (!(flgs & ERTS_SSI_FLG_WAITING)) {
@@ -2682,7 +2755,7 @@ scheduler_wait(int *fcalls, ErtsSchedulerData *esdp, ErtsRunQueue *rq)
 	if (flgs & ~ERTS_SSI_FLG_SUSPENDED)
 	    erts_smp_atomic32_read_band_nob(&ssi->flags, ERTS_SSI_FLG_SUSPENDED);
 
-	if (!thr_prgr_active) {
+	if (!ERTS_SCHEDULER_IS_DIRTY(esdp) && !thr_prgr_active) {
 	    erts_thr_progress_active(esdp, thr_prgr_active = 1);
 	    sched_wall_time_change(esdp, 1);
 	}
@@ -2699,6 +2772,9 @@ scheduler_wait(int *fcalls, ErtsSchedulerData *esdp, ErtsRunQueue *rq)
 	erts_smp_atomic32_set_relb(&function_calls, 0);
 	*fcalls = 0;
 
+#ifdef ERTS_DIRTY_SCHEDULERS
+	ASSERT(!ERTS_SCHEDULER_IS_DIRTY(esdp));
+#endif
 	sched_waiting_sys(esdp->no, rq);
 
 
@@ -2912,6 +2988,34 @@ wake_scheduler(ErtsRunQueue *rq)
     erts_sched_finish_poke(ssi, flgs);
 }
 
+#ifdef ERTS_DIRTY_SCHEDULERS
+static void
+wake_dirty_scheduler(ErtsRunQueue *rq)
+{
+    ErtsSchedulerSleepInfo *ssi;
+    ErtsSchedulerSleepList *sl;
+
+    ASSERT(ERTS_RUNQ_IX_IS_DIRTY(rq->ix));
+
+    sl = &rq->sleepers;
+    erts_smp_spin_lock(&sl->lock);
+    ssi = sl->list;
+    if (!ssi)
+	erts_smp_spin_unlock(&sl->lock);
+    else {
+	sl->list = NULL;
+	erts_smp_spin_unlock(&sl->lock);
+
+	ERTS_THR_MEMORY_BARRIER;
+	do {
+	    ErtsSchedulerSleepInfo *wake_ssi = ssi;
+	    ssi = ssi->next;
+	    erts_sched_finish_poke(wake_ssi, ssi_flags_set_wake(wake_ssi));
+	} while (ssi);
+    }
+}
+#endif
+
 #define ERTS_NO_USED_RUNQS_SHIFT 16
 #define ERTS_NO_RUNQS_MASK 0xffff
 
@@ -3047,8 +3151,14 @@ static ERTS_INLINE void
 smp_notify_inc_runq(ErtsRunQueue *runq)
 {
 #ifdef ERTS_SMP
-    if (runq)
-	wake_scheduler(runq);
+    if (runq) {
+#ifdef ERTS_DIRTY_SCHEDULERS
+	if (ERTS_RUNQ_IX_IS_DIRTY(runq->ix))
+	    wake_dirty_scheduler(runq);
+	else
+#endif
+	    wake_scheduler(runq);
+    }
 #endif
 }
 
@@ -4899,7 +5009,10 @@ erts_sched_set_wake_cleanup_threshold(char *str)
 static void
 init_aux_work_data(ErtsAuxWorkData *awdp, ErtsSchedulerData *esdp, char *dawwp)
 {
-    awdp->sched_id = esdp ? (int) esdp->no : 0;
+    if (!esdp || ERTS_SCHEDULER_IS_DIRTY(esdp))
+	awdp->sched_id = 0;
+    else
+	awdp->sched_id = (int) esdp->no;
     awdp->esdp = esdp;
     awdp->ssi = esdp ? esdp->ssi : NULL;
 #ifdef ERTS_SMP
@@ -4939,14 +5052,71 @@ init_aux_work_data(ErtsAuxWorkData *awdp, ErtsSchedulerData *esdp, char *dawwp)
 #endif
 }
 
+static void
+init_scheduler_data(ErtsSchedulerData* esdp, int num,
+		    ErtsSchedulerSleepInfo* ssi,
+		    ErtsRunQueue* runq,
+		    char** daww_ptr, size_t daww_sz)
+{
+#ifdef ERTS_SMP
+    erts_bits_init_state(&esdp->erl_bits_state);
+    esdp->match_pseudo_process = NULL;
+    esdp->free_process = NULL;
+#endif
+    esdp->x_reg_array =
+	erts_alloc_permanent_cache_aligned(ERTS_ALC_T_BEAM_REGISTER,
+					   ERTS_X_REGS_ALLOCATED *
+					   sizeof(Eterm));
+    esdp->f_reg_array =
+	erts_alloc_permanent_cache_aligned(ERTS_ALC_T_BEAM_REGISTER,
+					   MAX_REG * sizeof(FloatDef));
+#if !HEAP_ON_C_STACK
+    esdp->num_tmp_heap_used = 0;
+#endif
+#ifdef ERTS_DIRTY_SCHEDULERS
+    if (ERTS_RUNQ_IX_IS_DIRTY(runq->ix)) {
+	esdp->no = 0;
+	esdp->dirty_no = (Uint) num;
+    }
+    else {
+	esdp->no = (Uint) num;
+	esdp->dirty_no = 0;
+    }
+#else
+    esdp->no = (Uint) num;
+#endif
+    esdp->ssi = ssi;
+    esdp->current_process = NULL;
+    esdp->current_port = NULL;
+
+    esdp->virtual_reds = 0;
+    esdp->cpu_id = -1;
+
+    erts_init_atom_cache_map(&esdp->atom_cache_map);
+
+    esdp->run_queue = runq;
+    esdp->run_queue->scheduler = esdp;
+
+    if (daww_ptr) {
+	init_aux_work_data(&esdp->aux_work_data, esdp, *daww_ptr);
+#ifdef ERTS_SMP
+	*daww_ptr += daww_sz;
+#endif
+    }
+
+    esdp->reductions = 0;
+
+    init_sched_wall_time(&esdp->sched_wall_time);
+    erts_port_task_handle_init(&esdp->nosuspend_port_task_handle);
+}
+
 void
 erts_init_scheduling(int no_schedulers, int no_schedulers_online)
 {
     int ix, n, no_ssi;
     char *daww_ptr;
-#ifdef ERTS_SMP
     size_t daww_sz;
-#endif
+    size_t size_runqs;
 
     init_misc_op_list_alloc();
     init_proc_sys_task_queues_alloc();
@@ -4967,19 +5137,26 @@ erts_init_scheduling(int no_schedulers, int no_schedulers_online)
     /* Create and initialize run queues */
 
     n = no_schedulers;
-
-    erts_aligned_run_queues = 
-	erts_alloc_permanent_cache_aligned(ERTS_ALC_T_RUNQS,
-					   sizeof(ErtsAlignedRunQueue) * n);
+    size_runqs = sizeof(ErtsAlignedRunQueue) * (n + ERTS_NUM_DIRTY_RUNQS);
+    erts_aligned_run_queues =
+	erts_alloc_permanent_cache_aligned(ERTS_ALC_T_RUNQS, size_runqs);
 #ifdef ERTS_SMP
+#ifdef ERTS_DIRTY_SCHEDULERS
+    erts_aligned_run_queues += ERTS_NUM_DIRTY_RUNQS;
+#endif
     erts_smp_atomic32_init_nob(&no_empty_run_queues, 0);
 #endif
 
     erts_no_run_queues = n;
 
-    for (ix = 0; ix < n; ix++) {
+    for (ix = -(ERTS_NUM_DIRTY_RUNQS); ix < n; ix++) {
 	int pix, rix;
+#ifdef ERTS_DIRTY_SCHEDULERS
+	ErtsRunQueue *rq = ERTS_RUNQ_IX_IS_DIRTY(ix) ?
+	    ERTS_DIRTY_RUNQ_IX(ix) : ERTS_RUNQ_IX(ix);
+#else
 	ErtsRunQueue *rq = ERTS_RUNQ_IX(ix);
+#endif
 
 	rq->ix = ix;
 
@@ -4990,6 +5167,15 @@ erts_init_scheduling(int no_schedulers, int no_schedulers_online)
 	erts_smp_mtx_init_x(&rq->mtx, "run_queue", make_small(ix + 1));
 	erts_smp_cnd_init(&rq->cnd);
 
+#ifdef ERTS_DIRTY_SCHEDULERS
+#ifdef ERTS_SMP
+	if (ERTS_RUNQ_IX_IS_DIRTY(ix)) {
+	    erts_smp_spinlock_init(&rq->sleepers.lock, "dirty_run_queue_sleep_list");
+	    rq->sleepers.list = NULL;
+	}
+#endif
+#endif
+
 	rq->waiting = 0;
 	rq->woken = 0;
 	ERTS_RUNQ_FLGS_INIT(rq, ERTS_RUNQ_FLG_NONEMPTY);
@@ -5076,6 +5262,29 @@ erts_init_scheduling(int no_schedulers, int no_schedulers_online)
 
 #ifdef ERTS_SMP
     aligned_sched_sleep_info++;
+
+#ifdef ERTS_DIRTY_SCHEDULERS
+    aligned_dirty_cpu_sched_sleep_info =
+	erts_alloc_permanent_cache_aligned(
+	    ERTS_ALC_T_SCHDLR_SLP_INFO,
+	    erts_no_dirty_cpu_schedulers*sizeof(ErtsAlignedSchedulerSleepInfo));
+    for (ix = 0; ix < erts_no_dirty_cpu_schedulers; ix++) {
+	ErtsSchedulerSleepInfo *ssi = &aligned_dirty_cpu_sched_sleep_info[ix].ssi;
+	erts_smp_atomic32_init_nob(&ssi->flags, 0);
+	ssi->event = NULL; /* initialized in sched_thread_func */
+	erts_atomic32_init_nob(&ssi->aux_work, 0);
+    }
+    aligned_dirty_io_sched_sleep_info =
+	erts_alloc_permanent_cache_aligned(
+	    ERTS_ALC_T_SCHDLR_SLP_INFO,
+	    erts_no_dirty_io_schedulers*sizeof(ErtsAlignedSchedulerSleepInfo));
+    for (ix = 0; ix < erts_no_dirty_io_schedulers; ix++) {
+	ErtsSchedulerSleepInfo *ssi = &aligned_dirty_io_sched_sleep_info[ix].ssi;
+	erts_smp_atomic32_init_nob(&ssi->flags, 0);
+	ssi->event = NULL; /* initialized in sched_thread_func */
+	erts_atomic32_init_nob(&ssi->aux_work, 0);
+    }
+#endif
 #endif
 
     /* Create and initialize scheduler specific data */
@@ -5086,6 +5295,7 @@ erts_init_scheduling(int no_schedulers, int no_schedulers_online)
     daww_ptr = erts_alloc_permanent_cache_aligned(ERTS_ALC_T_SCHDLR_DATA,
 						  daww_sz*n);
 #else
+    daww_sz = 0;
     daww_ptr = NULL;
 #endif
 
@@ -5095,46 +5305,32 @@ erts_init_scheduling(int no_schedulers, int no_schedulers_online)
 
     for (ix = 0; ix < n; ix++) {
 	ErtsSchedulerData *esdp = ERTS_SCHEDULER_IX(ix);
-#ifdef ERTS_SMP
-	erts_bits_init_state(&esdp->erl_bits_state);
-	esdp->match_pseudo_process = NULL;
-	esdp->free_process = NULL;
-#endif
-	esdp->x_reg_array =
-	    erts_alloc_permanent_cache_aligned(ERTS_ALC_T_BEAM_REGISTER,
-					       ERTS_X_REGS_ALLOCATED *
-					       sizeof(Eterm));
-	esdp->f_reg_array =
-	    erts_alloc_permanent_cache_aligned(ERTS_ALC_T_BEAM_REGISTER,
-					       MAX_REG * sizeof(FloatDef));
-#if !HEAP_ON_C_STACK
-	esdp->num_tmp_heap_used = 0;
-#endif
-	esdp->no = (Uint) ix+1;
-	esdp->ssi = ERTS_SCHED_SLEEP_INFO_IX(ix);
-	esdp->current_process = NULL;
-	esdp->current_port = NULL;
-
-	esdp->virtual_reds = 0;
-	esdp->cpu_id = -1;
-
-	erts_init_atom_cache_map(&esdp->atom_cache_map);
-
-	esdp->run_queue = ERTS_RUNQ_IX(ix);
-	esdp->run_queue->scheduler = esdp;
+	init_scheduler_data(esdp, ix+1, ERTS_SCHED_SLEEP_INFO_IX(ix),
+			    ERTS_RUNQ_IX(ix), &daww_ptr, daww_sz);
+    }
 
-	init_aux_work_data(&esdp->aux_work_data, esdp, daww_ptr);
+#ifdef ERTS_DIRTY_SCHEDULERS
 #ifdef ERTS_SMP
-	daww_ptr += daww_sz;
-#endif
-
-	esdp->reductions = 0;
-
-	init_sched_wall_time(&esdp->sched_wall_time);
-
-	erts_port_task_handle_init(&esdp->nosuspend_port_task_handle);
-
+    erts_aligned_dirty_cpu_scheduler_data =
+	erts_alloc_permanent_cache_aligned(
+					   ERTS_ALC_T_SCHDLR_DATA,
+					   erts_no_dirty_cpu_schedulers*sizeof(ErtsAlignedSchedulerData));
+    for (ix = 0; ix < erts_no_dirty_cpu_schedulers; ix++) {
+	ErtsSchedulerData *esdp = ERTS_DIRTY_CPU_SCHEDULER_IX(ix);
+	init_scheduler_data(esdp, ix+1, ERTS_DIRTY_CPU_SCHED_SLEEP_INFO_IX(ix),
+			    ERTS_DIRTY_CPU_RUNQ, NULL, 0);
+    }
+    erts_aligned_dirty_io_scheduler_data =
+	erts_alloc_permanent_cache_aligned(
+					   ERTS_ALC_T_SCHDLR_DATA,
+					   erts_no_dirty_io_schedulers*sizeof(ErtsAlignedSchedulerData));
+    for (ix = 0; ix < erts_no_dirty_io_schedulers; ix++) {
+	ErtsSchedulerData *esdp = ERTS_DIRTY_IO_SCHEDULER_IX(ix);
+	init_scheduler_data(esdp, ix+1, ERTS_DIRTY_IO_SCHED_SLEEP_INFO_IX(ix),
+			    ERTS_DIRTY_IO_RUNQ, NULL, 0);
     }
+#endif
+#endif
 
     init_misc_aux_work();
 #if !HALFWORD_HEAP
@@ -5198,6 +5394,10 @@ erts_init_scheduling(int no_schedulers, int no_schedulers_online)
 #endif
     }
     erts_no_schedulers = 1;
+#ifdef ERTS_DIRTY_SCHEDULERS
+    erts_no_dirty_cpu_schedulers = 0;
+    erts_no_dirty_io_schedulers = 0;
+#endif
 #endif
 
     erts_smp_atomic32_init_nob(&function_calls, 0);
@@ -5310,28 +5510,39 @@ check_enqueue_in_prio_queue(erts_aint32_t *prq_prio_p,
 
     *prq_prio_p = aprio;
 
-    max_qbit = (actual >> ERTS_PSFLGS_IN_PRQ_MASK_OFFSET) & ERTS_PSFLGS_QMASK;
-    max_qbit |= 1 << ERTS_PSFLGS_QMASK_BITS;
-    max_qbit &= -max_qbit;
-    /*
-     * max_qbit now either contain bit set for highest prio queue or a bit
-     * out of range (which will have a value larger than valid range).
-     */
+#ifdef ERTS_DIRTY_SCHEDULERS
+    if (!(actual & (ERTS_PSFLG_DIRTY_CPU_PROC|ERTS_PSFLG_DIRTY_IO_PROC))) {
+#endif
+	max_qbit = (actual >> ERTS_PSFLGS_IN_PRQ_MASK_OFFSET) & ERTS_PSFLGS_QMASK;
+	max_qbit |= 1 << ERTS_PSFLGS_QMASK_BITS;
+	max_qbit &= -max_qbit;
+	/*
+	 * max_qbit now either contain bit set for highest prio queue or a bit
+	 * out of range (which will have a value larger than valid range).
+	 */
 
-    if (qbit >= max_qbit)
-	return 0; /* Already queued in higher or equal prio */
+	if (qbit >= max_qbit)
+	    return 0; /* Already queued in higher or equal prio */
 
-    /* Need to enqueue (if already enqueued, it is in lower prio) */
-    *newp |= qbit << ERTS_PSFLGS_IN_PRQ_MASK_OFFSET;
+	/* Need to enqueue (if already enqueued, it is in lower prio) */
+	*newp |= qbit << ERTS_PSFLGS_IN_PRQ_MASK_OFFSET;
 
-    if ((actual & (ERTS_PSFLG_IN_RUNQ|ERTS_PSFLGS_USR_PRIO_MASK))
-	!= (aprio << ERTS_PSFLGS_USR_PRIO_OFFSET)) {
-	/*
-	 * Process struct already enqueued, or actual prio not
-	 * equal to user prio, i.e., enqueue using proxy.
-	 */
-	return -1;
+	if ((actual & (ERTS_PSFLG_IN_RUNQ|ERTS_PSFLGS_USR_PRIO_MASK))
+	    != (aprio << ERTS_PSFLGS_USR_PRIO_OFFSET)) {
+	    /*
+	     * Process struct already enqueued, or actual prio not
+	     * equal to user prio, i.e., enqueue using proxy.
+	     */
+	    return -1;
+	}
+#ifdef ERTS_DIRTY_SCHEDULERS
+    } else {
+	if (actual & ERTS_PSFLG_DIRTY_CPU_PROC)
+	    *newp |= ERTS_PSFLG_DIRTY_CPU_PROC_IN_Q;
+	else
+	    *newp |= ERTS_PSFLG_DIRTY_IO_PROC_IN_Q;
     }
+#endif
 
     /*
      * Enqueue using process struct.
@@ -5387,10 +5598,21 @@ schedule_out_process(ErtsRunQueue *c_rq, erts_aint32_t state, Process *p, Proces
     }
     else {
 	Process *sched_p;
-	ErtsRunQueue *runq = erts_get_runq_proc(p);
+	ErtsRunQueue *runq;
 
 	ASSERT(!(n & ERTS_PSFLG_SUSPENDED) || (n & ERTS_PSFLG_ACTIVE_SYS));
 
+#ifdef ERTS_DIRTY_SCHEDULERS
+#ifdef ERTS_SMP
+	if (ERTS_PSFLG_DIRTY_CPU_PROC & a)
+	    runq = ERTS_DIRTY_CPU_RUNQ;
+	else if (ERTS_PSFLG_DIRTY_IO_PROC & a)
+	    runq = ERTS_DIRTY_IO_RUNQ;
+	else
+#endif
+#endif
+	    runq = erts_get_runq_proc(p);
+
 	if (enqueue < 0)
 	    sched_p = make_proxy_proc(proxy, p, enq_prio);
 	else {
@@ -5400,7 +5622,11 @@ schedule_out_process(ErtsRunQueue *c_rq, erts_aint32_t state, Process *p, Proces
 	}
 
 #ifdef ERTS_SMP
-	if (!(ERTS_PSFLG_BOUND & n)) {
+	if (!(ERTS_PSFLG_BOUND & n)
+#ifdef ERTS_DIRTY_SCHEDULERS
+	    && !(n & (ERTS_PSFLG_DIRTY_CPU_PROC_IN_Q|ERTS_PSFLG_DIRTY_IO_PROC_IN_Q))
+#endif
+	    ) {
 	    ErtsRunQueue *new_runq = erts_check_emigration_need(runq, enq_prio);
 	    if (new_runq) {
 		RUNQ_SET_RQ(&sched_p->run_queue, new_runq);
@@ -5827,6 +6053,9 @@ suspend_scheduler(ErtsSchedulerData *esdp)
      * Regardless of why a scheduler is suspended, it ends up here.
      */
 
+#ifdef ERTS_DIRTY_SCHEDULERS
+    ASSERT(!ERTS_SCHEDULER_IS_DIRTY(esdp));
+#endif
     ASSERT(no != 1);
 
     evacuate_run_queue(esdp->run_queue, &sbp);
@@ -5994,22 +6223,44 @@ ErtsSchedSuspendResult
 erts_schedulers_state(Uint *total,
 		      Uint *online,
 		      Uint *active,
+		      Uint *dirty_cpu,
+		      Uint *dirty_cpu_online,
+		      Uint *dirty_io,
 		      int yield_allowed)
 {
-    int res;
+    int res = ERTS_SCHDLR_SSPND_EINVAL;
     erts_aint32_t changing;
-    erts_smp_mtx_lock(&schdlr_sspnd.mtx);
-    changing = erts_smp_atomic32_read_nob(&schdlr_sspnd.changing);
-    if (yield_allowed && (changing & ~ERTS_SCHDLR_SSPND_CHNG_WAITER))
-	res = ERTS_SCHDLR_SSPND_YIELD_RESTART;
-    else {
-	*active = *online = schdlr_sspnd.online;
-	if (ongoing_multi_scheduling_block())
-	    *active = 1;
-	res = ERTS_SCHDLR_SSPND_DONE;
+    if (total) {
+	ASSERT(online);
+	ASSERT(active);
+	erts_smp_mtx_lock(&schdlr_sspnd.mtx);
+	changing = erts_smp_atomic32_read_nob(&schdlr_sspnd.changing);
+	if (yield_allowed && (changing & ~ERTS_SCHDLR_SSPND_CHNG_WAITER))
+	    res = ERTS_SCHDLR_SSPND_YIELD_RESTART;
+	else {
+	    *active = *online = schdlr_sspnd.online;
+	    if (ongoing_multi_scheduling_block())
+		*active = 1;
+	    res = ERTS_SCHDLR_SSPND_DONE;
+	}
+	erts_smp_mtx_unlock(&schdlr_sspnd.mtx);
+	*total = erts_no_schedulers;
     }
-    erts_smp_mtx_unlock(&schdlr_sspnd.mtx);
-    *total = erts_no_schedulers;
+#ifdef ERTS_DIRTY_SCHEDULERS
+    if (dirty_cpu)
+	*dirty_cpu = erts_no_dirty_cpu_schedulers;
+    if (dirty_cpu_online)
+	*dirty_cpu_online = erts_no_dirty_cpu_schedulers_online;
+    if (dirty_io)
+	*dirty_io = erts_no_dirty_io_schedulers;
+#else
+    if (dirty_cpu)
+	*dirty_cpu = 0;
+    if (dirty_cpu_online)
+	*dirty_cpu_online = 0;
+    if (dirty_io)
+	*dirty_io = 0;
+#endif
     return res;
 }
 
@@ -6101,6 +6352,10 @@ erts_set_schedulers_online(Process *p,
 			ErtsRunQueue *rq = ERTS_RUNQ_IX(ix);
 			wake_scheduler(rq);
 		    }
+#ifdef ERTS_DIRTY_SCHEDULERS
+		    wake_dirty_scheduler(ERTS_DIRTY_CPU_RUNQ);
+		    wake_dirty_scheduler(ERTS_DIRTY_IO_RUNQ);
+#endif
 		}
 	    }
 
@@ -6448,6 +6703,92 @@ sched_thread_func(void *vesdp)
     return NULL;
 }
 
+#ifdef ERTS_DIRTY_SCHEDULERS
+#ifdef ERTS_SMP
+static void*
+sched_dirty_cpu_thread_func(void *vesdp)
+{
+    ErtsThrPrgrCallbacks callbacks;
+    ErtsSchedulerData *esdp = vesdp;
+    Uint no = esdp->dirty_no;
+    ERTS_DIRTY_CPU_SCHED_SLEEP_INFO_IX(no-1)->event = erts_tse_fetch();
+    callbacks.arg = (void *) esdp->ssi;
+    callbacks.wakeup = thr_prgr_wakeup;
+    callbacks.prepare_wait = NULL;
+    callbacks.wait = NULL;
+    callbacks.finalize_wait = NULL;
+
+    erts_thr_progress_register_unmanaged_thread(&callbacks);
+#ifdef ERTS_ENABLE_LOCK_CHECK
+    {
+	char buf[31];
+	erts_snprintf(&buf[0], 31, "dirty cpu scheduler %beu", no);
+	erts_lc_set_thread_name(&buf[0]);
+    }
+#endif
+    erts_tsd_set(sched_data_key, vesdp);
+#if ERTS_USE_ASYNC_READY_Q
+    esdp->aux_work_data.async_ready.queue = NULL;
+#endif
+
+    erts_proc_lock_prepare_proc_lock_waiter();
+
+#ifdef HIPE
+    hipe_thread_signal_init();
+#endif
+    erts_thread_init_float();
+
+    process_main();
+    /* No schedulers should *ever* terminate */
+    erl_exit(ERTS_ABORT_EXIT,
+	     "Dirty CPU scheduler thread number %beu terminated\n",
+	     no);
+    return NULL;
+}
+
+static void*
+sched_dirty_io_thread_func(void *vesdp)
+{
+    ErtsThrPrgrCallbacks callbacks;
+    ErtsSchedulerData *esdp = vesdp;
+    Uint no = esdp->dirty_no;
+    ERTS_DIRTY_IO_SCHED_SLEEP_INFO_IX(no-1)->event = erts_tse_fetch();
+    callbacks.arg = (void *) esdp->ssi;
+    callbacks.wakeup = thr_prgr_wakeup;
+    callbacks.prepare_wait = NULL;
+    callbacks.wait = NULL;
+    callbacks.finalize_wait = NULL;
+
+    erts_thr_progress_register_unmanaged_thread(&callbacks);
+#ifdef ERTS_ENABLE_LOCK_CHECK
+    {
+	char buf[31];
+	erts_snprintf(&buf[0], 31, "dirty io scheduler %beu", no);
+	erts_lc_set_thread_name(&buf[0]);
+    }
+#endif
+    erts_tsd_set(sched_data_key, vesdp);
+#if ERTS_USE_ASYNC_READY_Q
+    esdp->aux_work_data.async_ready.queue = NULL;
+#endif
+
+    erts_proc_lock_prepare_proc_lock_waiter();
+
+#ifdef HIPE
+    hipe_thread_signal_init();
+#endif
+    erts_thread_init_float();
+
+    process_main();
+    /* No schedulers should *ever* terminate */
+    erl_exit(ERTS_ABORT_EXIT,
+	     "Dirty I/O scheduler thread number %beu terminated\n",
+	     no);
+    return NULL;
+}
+#endif
+#endif
+
 static ethr_tid aux_tid;
 
 void
@@ -6498,6 +6839,26 @@ erts_start_schedulers(void)
     
     erts_no_schedulers = actual;
 
+#ifdef ERTS_DIRTY_SCHEDULERS
+#ifdef ERTS_SMP
+    {
+	int ix;
+	for (ix = 0; ix < erts_no_dirty_cpu_schedulers; ix++) {
+	    ErtsSchedulerData *esdp = ERTS_DIRTY_CPU_SCHEDULER_IX(ix);
+	    res = ethr_thr_create(&esdp->tid,sched_dirty_cpu_thread_func,(void*)esdp,&opts);
+	    if (res != 0)
+		erl_exit(1, "Failed to create dirty cpu scheduler thread %d\n", ix);
+	}
+	for (ix = 0; ix < erts_no_dirty_io_schedulers; ix++) {
+	    ErtsSchedulerData *esdp = ERTS_DIRTY_IO_SCHEDULER_IX(ix);
+	    res = ethr_thr_create(&esdp->tid,sched_dirty_io_thread_func,(void*)esdp,&opts);
+	    if (res != 0)
+		erl_exit(1, "Failed to create dirty io scheduler thread %d\n", ix);
+	}
+    }
+#endif
+#endif
+
     ERTS_THR_MEMORY_BARRIER;
 
     res = ethr_thr_create(&aux_tid, aux_thread, NULL, &opts);
@@ -7486,7 +7847,8 @@ Process *schedule(Process *p, int calls)
 	input_reductions = INPUT_REDUCTIONS;
     }
 
-    ERTS_SMP_LC_ASSERT(!erts_thr_progress_is_blocking());
+    ERTS_SMP_LC_ASSERT(ERTS_SCHEDULER_IS_DIRTY(erts_get_scheduler_data())
+		       || !erts_thr_progress_is_blocking());
 
     /*
      * Clean up after the process being scheduled out.
@@ -7597,7 +7959,8 @@ Process *schedule(Process *p, int calls)
 
     }
 
-    ERTS_SMP_LC_ASSERT(!erts_thr_progress_is_blocking());
+    ERTS_SMP_LC_ASSERT(ERTS_SCHEDULER_IS_DIRTY(esdp)
+		       || !erts_thr_progress_is_blocking());
 
  check_activities_to_run: {
 #ifdef ERTS_SMP
@@ -7611,22 +7974,25 @@ Process *schedule(Process *p, int calls)
 	    erts_smp_runq_lock(rq);
 	}
 
-	if (rq->check_balance_reds <= 0)
-	    check_balance(rq);
+	if (!ERTS_SCHEDULER_IS_DIRTY(esdp)) {
+	    if (rq->check_balance_reds <= 0)
+		check_balance(rq);
 
-	ERTS_SMP_LC_ASSERT(!erts_thr_progress_is_blocking());
-	ERTS_SMP_LC_ASSERT(erts_smp_lc_runq_is_locked(rq));
+	    ERTS_SMP_LC_ASSERT(!erts_thr_progress_is_blocking());
 
-	mps = erts_get_migration_paths_managed();
-	mp = &mps->mpath[rq->ix];
+	    mps = erts_get_migration_paths_managed();
+	    mp = &mps->mpath[rq->ix];
 
-	if (mp->flags & ERTS_RUNQ_FLGS_IMMIGRATE_QMASK)
-	    immigrate(rq, mp);
+	    if (mp->flags & ERTS_RUNQ_FLGS_IMMIGRATE_QMASK)
+		immigrate(rq, mp);
+	}
 
+	ERTS_SMP_LC_ASSERT(erts_smp_lc_runq_is_locked(rq));
     continue_check_activities_to_run:
 	flags = ERTS_RUNQ_FLGS_GET_NOB(rq);
     continue_check_activities_to_run_known_flags:
-	ASSERT(flags & ERTS_RUNQ_FLG_NONEMPTY);
+	ASSERT(ERTS_SCHEDULER_IS_DIRTY(esdp)
+	       || flags & ERTS_RUNQ_FLG_NONEMPTY);
 
 	if (flags & (ERTS_RUNQ_FLG_CHK_CPU_BIND|ERTS_RUNQ_FLG_SUSPENDED)) {
 	
@@ -7641,7 +8007,7 @@ Process *schedule(Process *p, int calls)
 	    }
 	}
 
-	{
+	if (!ERTS_SCHEDULER_IS_DIRTY(esdp)) {
 	    erts_aint32_t aux_work;
 	    int leader_update = erts_thr_progress_update(esdp);
 	    aux_work = erts_atomic32_read_acqb(&esdp->ssi->aux_work);
@@ -7653,9 +8019,9 @@ Process *schedule(Process *p, int calls)
 		    handle_aux_work(&esdp->aux_work_data, aux_work, 0);
 		erts_smp_runq_lock(rq);
 	    }
-	}
 
-	ERTS_SMP_LC_ASSERT(!erts_thr_progress_is_blocking());
+	    ERTS_SMP_LC_ASSERT(!erts_thr_progress_is_blocking());
+	}
 	ERTS_SMP_LC_ASSERT(erts_smp_lc_runq_is_locked(rq));
 
 #else /* ERTS_SMP */
@@ -7684,7 +8050,7 @@ Process *schedule(Process *p, int calls)
 	    if (flags & ERTS_RUNQ_FLG_INACTIVE)
 		empty_runq(rq);
 	    else {
-		if (try_steal_task(rq))
+		if (!ERTS_RUNQ_IX_IS_DIRTY(rq->ix) && try_steal_task(rq))
 		    goto continue_check_activities_to_run;
 
 		empty_runq(rq);
@@ -7710,7 +8076,8 @@ Process *schedule(Process *p, int calls)
 
 	    goto check_activities_to_run;
 	}
-	else if (fcalls > input_reductions && prepare_for_sys_schedule()) {
+	else if (!ERTS_SCHEDULER_IS_DIRTY(esdp) &&
+		 (fcalls > input_reductions && prepare_for_sys_schedule())) {
 	    /*
 	     * Schedule system-level activities.
 	     */
@@ -7814,6 +8181,14 @@ Process *schedule(Process *p, int calls)
 	    psflg_band_mask = ~(((erts_aint32_t) 1) << (ERTS_PSFLGS_GET_PRQ_PRIO(state)
 							+ ERTS_PSFLGS_IN_PRQ_MASK_OFFSET));
 
+#ifdef ERTS_DIRTY_SCHEDULERS
+	    /* if a non-dirty scheduler picks up a process marked as already being
+	       in a dirty run queue, just drop it and go get another process */
+	    if (state & (ERTS_PSFLG_DIRTY_CPU_PROC_IN_Q|ERTS_PSFLG_DIRTY_IO_PROC_IN_Q) &&
+		!ERTS_SCHEDULER_IS_DIRTY(esdp))
+		goto pick_next_process;
+#endif
+
 	    if (!(state & ERTS_PSFLG_PROXY))
 		psflg_band_mask &= ~ERTS_PSFLG_IN_RUNQ;
 	    else {
@@ -7896,6 +8271,10 @@ Process *schedule(Process *p, int calls)
 					  (UWord) esdp->no);
 	    int migrated = old && old != esdp->no;
 
+#ifdef ERTS_DIRTY_SCHEDULERS
+	    ASSERT(!ERTS_SCHEDULER_IS_DIRTY(esdp));
+#endif
+
 	    prio = (int) ERTS_PSFLGS_GET_USR_PRIO(state);
 
 	    erts_smp_spin_lock(&erts_sched_stat.lock);
@@ -9706,8 +10085,12 @@ save_pending_exiter(Process *p)
     non_empty_runq(rq);
 
     erts_smp_runq_unlock(rq);
-
-    wake_scheduler(rq);
+#ifdef ERTS_DIRTY_SCHEDULERS
+    if (ERTS_RUNQ_IX_IS_DIRTY(rq->ix))
+	wake_dirty_scheduler(rq);
+    else
+#endif
+	wake_scheduler(rq);
 }
 
 #endif
diff --git a/erts/emulator/beam/erl_process.h b/erts/emulator/beam/erl_process.h
index 24832d59b5..dcb9251d0d 100644
--- a/erts/emulator/beam/erl_process.h
+++ b/erts/emulator/beam/erl_process.h
@@ -74,6 +74,10 @@ struct ErtsNodesMonitor_;
 #define ERTS_HAVE_SCHED_UTIL_BALANCING_SUPPORT		0
 
 #define ERTS_MAX_NO_OF_SCHEDULERS 1024
+#ifdef ERTS_DIRTY_SCHEDULERS
+#define ERTS_MAX_NO_OF_DIRTY_CPU_SCHEDULERS ERTS_MAX_NO_OF_SCHEDULERS
+#define ERTS_MAX_NO_OF_DIRTY_IO_SCHEDULERS ERTS_MAX_NO_OF_SCHEDULERS
+#endif
 
 #define ERTS_DEFAULT_MAX_PROCESSES (1 << 18)
 
@@ -103,6 +107,11 @@ extern Export exp_send, exp_receive, exp_timeout;
 extern int erts_sched_compact_load;
 extern int erts_sched_balance_util;
 extern Uint erts_no_schedulers;
+#ifdef ERTS_DIRTY_SCHEDULERS
+extern Uint erts_no_dirty_cpu_schedulers;
+extern Uint erts_no_dirty_cpu_schedulers_online;
+extern Uint erts_no_dirty_io_schedulers;
+#endif
 extern Uint erts_no_run_queues;
 extern int erts_sched_thread_suggested_stack_size;
 #define ERTS_SCHED_THREAD_MIN_STACK_SIZE 4	/* Kilo words */
@@ -275,6 +284,13 @@ typedef enum {
 
 typedef struct ErtsSchedulerSleepInfo_ ErtsSchedulerSleepInfo;
 
+#ifdef ERTS_DIRTY_SCHEDULERS
+typedef struct {
+    erts_smp_spinlock_t lock;
+    ErtsSchedulerSleepInfo *list;
+} ErtsSchedulerSleepList;
+#endif
+
 struct ErtsSchedulerSleepInfo_ {
 #ifdef ERTS_SMP
     ErtsSchedulerSleepInfo *next;
@@ -387,6 +403,12 @@ struct ErtsRunQueue_ {
     erts_smp_mtx_t mtx;
     erts_smp_cnd_t cnd;
 
+#ifdef ERTS_DIRTY_SCHEDULERS
+#ifdef ERTS_SMP
+    ErtsSchedulerSleepList sleepers;
+#endif
+#endif
+
     ErtsSchedulerData *scheduler;
     int waiting; /* < 0 in sys schedule; > 0 on cnd variable */
     int woken;
@@ -546,7 +568,10 @@ struct ErtsSchedulerData_ {
 #endif
     ErtsSchedulerSleepInfo *ssi;
     Process *current_process;
-    Uint no;			/* Scheduler number */
+    Uint no;			/* Scheduler number for normal schedulers */
+#ifdef ERTS_DIRTY_SCHEDULERS
+    Uint dirty_no;		/* Scheduler number for dirty schedulers */
+#endif
     Port *current_port;
     ErtsRunQueue *run_queue;
     int virtual_reds;
@@ -573,6 +598,10 @@ typedef union {
 } ErtsAlignedSchedulerData;
 
 extern ErtsAlignedSchedulerData *erts_aligned_scheduler_data;
+#ifdef ERTS_DIRTY_SCHEDULERS
+extern ErtsAlignedSchedulerData *erts_aligned_dirty_cpu_scheduler_data;
+extern ErtsAlignedSchedulerData *erts_aligned_dirty_io_scheduler_data;
+#endif
 
 #ifndef ERTS_SMP
 extern ErtsSchedulerData *erts_scheduler_data;
@@ -684,8 +713,13 @@ erts_smp_reset_max_len(ErtsRunQueue *rq, ErtsRunQueueInfo *rqi)
 #define ERTS_PSD_DIST_ENTRY			3
 #define ERTS_PSD_CALL_TIME_BP			4
 #define ERTS_PSD_DELAYED_GC_TASK_QS		5
+#ifdef ERTS_DIRTY_SCHEDULERS
+#define ERTS_PSD_DIRTY_SCHED_TRAP_EXPORT	6
 
+#define ERTS_PSD_SIZE				7
+#else
 #define ERTS_PSD_SIZE				6
+#endif
 
 typedef struct {
     void *data[ERTS_PSD_SIZE];
@@ -712,6 +746,11 @@ typedef struct {
 #define ERTS_PSD_DELAYED_GC_TASK_QS_GET_LOCKS ERTS_PROC_LOCK_MAIN
 #define ERTS_PSD_DELAYED_GC_TASK_QS_SET_LOCKS ERTS_PROC_LOCK_MAIN
 
+#ifdef ERTS_DIRTY_SCHEDULERS
+#define ERTS_PSD_DIRTY_SCHED_TRAP_EXPORT_GET_LOCKS ERTS_PROC_LOCK_MAIN
+#define ERTS_PSD_DIRTY_SCHED_TRAP_EXPORT_SET_LOCKS ERTS_PROC_LOCK_MAIN
+#endif
+
 typedef struct {
     ErtsProcLocks get_locks;
     ErtsProcLocks set_locks;
@@ -1025,6 +1064,12 @@ void erts_check_for_holes(Process* p);
 #define ERTS_PSFLG_RUNNING_SYS		ERTS_PSFLG_BIT(15)
 #define ERTS_PSFLG_PROXY		ERTS_PSFLG_BIT(16)
 #define ERTS_PSFLG_DELAYED_SYS		ERTS_PSFLG_BIT(17)
+#ifdef ERTS_DIRTY_SCHEDULERS
+#define ERTS_PSFLG_DIRTY_CPU_PROC	ERTS_PSFLG_BIT(18)
+#define ERTS_PSFLG_DIRTY_IO_PROC	ERTS_PSFLG_BIT(19)
+#define ERTS_PSFLG_DIRTY_CPU_PROC_IN_Q	ERTS_PSFLG_BIT(20)
+#define ERTS_PSFLG_DIRTY_IO_PROC_IN_Q	ERTS_PSFLG_BIT(21)
+#endif
 
 #define ERTS_PSFLGS_IN_PRQ_MASK 	(ERTS_PSFLG_IN_PRQ_MAX		\
 					 | ERTS_PSFLG_IN_PRQ_HIGH	\
@@ -1230,12 +1275,46 @@ extern struct erts_system_profile_flags_t erts_system_profile_flags;
 	    (p)->flags &= ~F_TIMO; \
     } while (0)
 
+#if defined(ERTS_DIRTY_SCHEDULERS) && defined(ERTS_SMP)
+#define ERTS_NUM_DIRTY_RUNQS 2
+#else
+#define ERTS_NUM_DIRTY_RUNQS 0
+#endif
+
 #define ERTS_RUNQ_IX(IX)						\
   (ASSERT(0 <= (IX) && (IX) < erts_no_run_queues),			\
    &erts_aligned_run_queues[(IX)].runq)
+#ifdef ERTS_DIRTY_SCHEDULERS
+#define ERTS_RUNQ_IX_IS_DIRTY(IX)					\
+  (-(ERTS_NUM_DIRTY_RUNQS) <= (IX) && (IX) < 0)
+#define ERTS_DIRTY_RUNQ_IX(IX)						\
+  (ASSERT(ERTS_RUNQ_IX_IS_DIRTY(IX)),					\
+   &erts_aligned_run_queues[(IX)].runq)
+#define ERTS_DIRTY_CPU_RUNQ (&erts_aligned_run_queues[-1].runq)
+#define ERTS_DIRTY_IO_RUNQ  (&erts_aligned_run_queues[-2].runq)
+#else
+#define ERTS_RUNQ_IX_IS_DIRTY(IX) 0
+#endif
 #define ERTS_SCHEDULER_IX(IX)						\
   (ASSERT(0 <= (IX) && (IX) < erts_no_schedulers),			\
    &erts_aligned_scheduler_data[(IX)].esd)
+#ifdef ERTS_DIRTY_SCHEDULERS
+#define ERTS_DIRTY_CPU_SCHEDULER_IX(IX)					\
+  (ASSERT(0 <= (IX) && (IX) < erts_no_dirty_cpu_schedulers),		\
+   &erts_aligned_dirty_cpu_scheduler_data[(IX)].esd)
+#define ERTS_DIRTY_IO_SCHEDULER_IX(IX)					\
+  (ASSERT(0 <= (IX) && (IX) < erts_no_dirty_io_schedulers),		\
+   &erts_aligned_dirty_io_scheduler_data[(IX)].esd)
+#ifdef ERTS_SMP
+#define ERTS_SCHEDULER_IS_DIRTY(ESDP)					\
+  ((ESDP)->dirty_no != 0)
+#else
+#define ERTS_SCHEDULER_IS_DIRTY(ESDP) 0
+#endif
+#else
+#define ERTS_RUNQ_IX_IS_DIRTY(IX) 0
+#define ERTS_SCHEDULER_IS_DIRTY(ESDP) 0
+#endif
 
 void erts_pre_init_process(void);
 void erts_late_init_process(void);
@@ -1438,9 +1517,11 @@ int erts_dbg_check_halloc_lock(Process *p);
 void erts_dbg_multi_scheduling_return_trap(Process *, Eterm);
 #endif
 int erts_get_max_no_executing_schedulers(void);
-#ifdef ERTS_SMP
+#if defined(ERTS_SMP) || defined(ERTS_DIRTY_SCHEDULERS)
 ErtsSchedSuspendResult
-erts_schedulers_state(Uint *, Uint *, Uint *, int);
+erts_schedulers_state(Uint *, Uint *, Uint *, Uint *, Uint *, Uint *, int);
+#endif
+#ifdef ERTS_SMP
 ErtsSchedSuspendResult
 erts_set_schedulers_online(Process *p,
 			   ErtsProcLocks plocks,
@@ -1558,7 +1639,7 @@ do {										\
     ErtsSchedulerData *esdp__ = ((P)						\
 				 ? ERTS_PROC_GET_SCHDATA((Process *) (P))	\
 				 : erts_get_scheduler_data());			\
-    if (esdp__)									\
+    if (esdp__ && !ERTS_SCHEDULER_IS_DIRTY(esdp__))				\
 	esdp__->verify_unused_temp_alloc(					\
 	    esdp__->verify_unused_temp_alloc_data);				\
 } while (0)
@@ -1693,6 +1774,13 @@ erts_psd_set(Process *p, ErtsProcLocks plocks, int ix, void *data)
 #define ERTS_PROC_SET_DELAYED_GC_TASK_QS(P, L, PBT) \
     ((ErtsProcSysTaskQs *) erts_psd_set((P), (L), ERTS_PSD_DELAYED_GC_TASK_QS, (void *) (PBT)))
 
+#ifdef ERTS_DIRTY_SCHEDULERS
+#define ERTS_PROC_GET_DIRTY_SCHED_TRAP_EXPORT(P) \
+    ((Export *) erts_psd_get((P), ERTS_PSD_DIRTY_SCHED_TRAP_EXPORT))
+#define ERTS_PROC_SET_DIRTY_SCHED_TRAP_EXPORT(P, L, DSTE) \
+    ((Export *) erts_psd_set((P), (L), ERTS_PSD_DIRTY_SCHED_TRAP_EXPORT, (void *) (DSTE)))
+#endif
+
 
 ERTS_GLB_INLINE Eterm erts_proc_get_error_handler(Process *p);
 ERTS_GLB_INLINE Eterm erts_proc_set_error_handler(Process *p,
@@ -1886,7 +1974,12 @@ Uint erts_get_scheduler_id(void)
 {
 #ifdef ERTS_SMP
     ErtsSchedulerData *esdp = erts_get_scheduler_data();
-    return esdp ? esdp->no : (Uint) 0;
+#ifdef ERTS_DIRTY_SCHEDULERS
+    if (esdp && ERTS_SCHEDULER_IS_DIRTY(esdp))
+	return 0;
+    else
+#endif
+	return esdp ? esdp->no : (Uint) 0;
 #else
     return erts_get_scheduler_data() ? (Uint) 1 : (Uint) 0;
 #endif