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Add a scheduler array for BpData at BeamInstr[-4]
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To solve the issue of multiple schedulers constantly updating the
head pointer to the bp data wheel, each scheduler now has its own
entrypoint to the wheel. This head pointer can be updated without
a locking being taken. Previously there were no lock ...
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@psyeugenic @RaimoNiskanen
psyeugenic authored and RaimoNiskanen committed Jun 3, 2010
1 parent 9a5848f commit ff9531e
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Showing 4 changed files with 190 additions and 108 deletions.
150 changes: 95 additions & 55 deletions erts/emulator/beam/beam_bp.c
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Expand Up @@ -101,6 +101,9 @@ do { \
(b)->prev = (a); \
} while (0)




/* *************************************************************************
** Local prototypes
*/
Expand All @@ -127,7 +130,7 @@ static int clear_function_break(Module *modp, BeamInstr *pc,
BeamInstr break_op);

static BpData *is_break(BeamInstr *pc, BeamInstr break_op);
static BpData *get_break(BeamInstr *pc, BeamInstr break_op);
static BpData *get_break(Process *p, BeamInstr *pc, BeamInstr break_op);

/* bp_hash */
#define BP_TIME_ADD(pi0, pi1) \
Expand Down Expand Up @@ -296,9 +299,12 @@ BeamInstr
erts_trace_break(Process *p, BeamInstr *pc, Eterm *args,
Uint32 *ret_flags, Eterm *tracer_pid) {
Eterm tpid1, tpid2;
BpDataTrace *bdt = (BpDataTrace *) pc[-4];
BpData **bds = (BpData **) (pc)[-4];
BpDataTrace *bdt = NULL;

ASSERT(bds);
ASSERT(pc[-5] == (BeamInstr) BeamOp(op_i_func_info_IaaI));
bdt = (BpDataTrace *) bds[bp_sched2ix_proc(p)];
ASSERT(bdt);
bdt = (BpDataTrace *) bdt->next;
ASSERT(bdt);
Expand All @@ -317,7 +323,7 @@ erts_trace_break(Process *p, BeamInstr *pc, Eterm *args,
bdt->tracer_pid = tpid2;
ErtsSmpBPUnlock(bdt);
}
pc[-4] = (BeamInstr) bdt;
bds[bp_sched2ix_proc(p)] = (BpData *) bdt;
return bdt->orig_instr;
}

Expand All @@ -329,12 +335,15 @@ erts_trace_break(Process *p, BeamInstr *pc, Eterm *args,
Uint32
erts_bif_mtrace(Process *p, BeamInstr *pc, Eterm *args, int local,
Eterm *tracer_pid) {
BpDataTrace *bdt = (BpDataTrace *) pc[-4];
BpData **bds = (BpData **) (pc)[-4];
BpDataTrace *bdt = NULL;


ASSERT(tracer_pid);
if (bdt) {
if (bds) {
Eterm tpid1, tpid2;
Uint32 flags;
bdt = (BpDataTrace *)bds[bp_sched2ix_proc(p)];

ErtsSmpBPLock(bdt);
tpid1 = tpid2 = bdt->tracer_pid;
Expand Down Expand Up @@ -520,15 +529,22 @@ erts_find_local_func(Eterm mfa[3]) {
}

/* bp_hash */

ERTS_INLINE Uint bp_sched2ix() {
#ifdef ERTS_SMP
ErtsSchedulerData *esdp;
esdp = erts_get_scheduler_data();
return esdp->no - 1;
#else
return 0;
#endif
}
static void bp_hash_init(bp_time_hash_t *hash, Uint n) {
Uint size = sizeof(bp_data_time_item_t)*n;
Uint i;

hash->n = n;
hash->used = 0;


hash->item = (bp_data_time_item_t *)Alloc(size);
sys_memzero(hash->item, size);

Expand Down Expand Up @@ -654,7 +670,6 @@ static void bp_time_diff(bp_data_time_item_t *item, /* out */
void erts_schedule_time_break(Process *p, Uint schedule) {
Uint ms, s, us;
process_breakpoint_time_t *pbt = NULL;
Uint ix = 0;
bp_data_time_item_t sitem, *item = NULL;
bp_time_hash_t *h = NULL;
BpDataTime *pbdt = NULL;
Expand All @@ -663,18 +678,7 @@ void erts_schedule_time_break(Process *p, Uint schedule) {

pbt = ERTS_PROC_GET_CALL_TIME(p);

#ifdef ERTS_SMP
ix = p->scheduler_data->no - 1;
#else
ix = 0;
#endif
/*
ASSERT( (p->status == P_RUNNING) ||
(p->status == P_WAITING) ||
(p->status == P_RUNABLE));
*/
if (pbt) {
get_sys_now(&ms,&s,&us);

switch(schedule) {
case ERTS_BP_CALL_TIME_SCHEDULE_EXITING :
Expand All @@ -685,13 +689,14 @@ void erts_schedule_time_break(Process *p, Uint schedule) {
* the previous breakpoint.
*/

pbdt = (BpDataTime *) get_break(pbt->pc, (Uint) BeamOp(op_i_time_breakpoint));
pbdt = (BpDataTime *) get_break(p, pbt->pc, (BeamInstr) BeamOp(op_i_time_breakpoint));
if (pbdt) {
get_sys_now(&ms,&s,&us);
bp_time_diff(&sitem, pbt, ms, s, us);
sitem.pid = p->id;
sitem.count = 0;

h = &(pbdt->hash[ix]);
h = &(pbdt->hash[bp_sched2ix_proc(p)]);

ASSERT(h);
ASSERT(h->item);
Expand All @@ -709,6 +714,7 @@ void erts_schedule_time_break(Process *p, Uint schedule) {
* timestamp it and remove the previous
* timestamp in the psd.
*/
get_sys_now(&ms,&s,&us);
pbt->ms = ms;
pbt->s = s;
pbt->us = us;
Expand All @@ -718,14 +724,6 @@ void erts_schedule_time_break(Process *p, Uint schedule) {
/* will never happen */
break;
}
#ifdef DEBUG
} else {
/* if pbt is null, then the process has just been spawned
* and status should be runnable.
*/
ASSERT( (p->status == P_RUNABLE) ||
(p->status == P_WAITING));
#endif
} /* pbt */
}

Expand All @@ -745,7 +743,6 @@ void erts_schedule_time_break(Process *p, Uint schedule) {
void erts_trace_time_break(Process *p, BeamInstr *pc, BpDataTime *bdt, Uint type) {
Uint ms,s,us;
process_breakpoint_time_t *pbt = NULL;
int ix = 0;
bp_data_time_item_t sitem, *item = NULL;
bp_time_hash_t *h = NULL;
BpDataTime *pbdt = NULL;
Expand All @@ -759,12 +756,6 @@ void erts_trace_time_break(Process *p, BeamInstr *pc, BpDataTime *bdt, Uint type
pbt = ERTS_PROC_GET_CALL_TIME(p);
get_sys_now(&ms,&s,&us);

#ifdef ERTS_SMP
ix = p->scheduler_data->no - 1;
#else
ix = 0;
#endif

switch(type) {
/* get pbt
* timestamp = t0
Expand All @@ -783,11 +774,11 @@ void erts_trace_time_break(Process *p, BeamInstr *pc, BpDataTime *bdt, Uint type
sitem.count = 0;

/* previous breakpoint */
pbdt = (BpDataTime *) get_break(pbt->pc, (Uint) BeamOp(op_i_time_breakpoint));
pbdt = (BpDataTime *) get_break(p, pbt->pc, (BeamInstr) BeamOp(op_i_time_breakpoint));

/* if null then the breakpoint was removed */
if (pbdt) {
h = &(pbdt->hash[ix]);
h = &(pbdt->hash[bp_sched2ix_proc(p)]);

ASSERT(h);
ASSERT(h->item);
Expand All @@ -813,7 +804,7 @@ void erts_trace_time_break(Process *p, BeamInstr *pc, BpDataTime *bdt, Uint type

/* this breakpoint */
ASSERT(bdt);
h = &(bdt->hash[ix]);
h = &(bdt->hash[bp_sched2ix_proc(p)]);

ASSERT(h);
ASSERT(h->item);
Expand Down Expand Up @@ -851,11 +842,11 @@ void erts_trace_time_break(Process *p, BeamInstr *pc, BpDataTime *bdt, Uint type
sitem.count = 0;

/* previous breakpoint */
pbdt = (BpDataTime *) get_break(pbt->pc, (Uint) BeamOp(op_i_time_breakpoint));
pbdt = (BpDataTime *) get_break(p, pbt->pc, (BeamInstr) BeamOp(op_i_time_breakpoint));

/* beware, the trace_pattern might have been removed */
if (pbdt) {

h = &(pbdt->hash[ix]);
h = &(pbdt->hash[bp_sched2ix_proc(p)]);

ASSERT(h);
ASSERT(h->item);
Expand All @@ -874,6 +865,10 @@ void erts_trace_time_break(Process *p, BeamInstr *pc, BpDataTime *bdt, Uint type
pbt->us = us;
}
break;
default :
ASSERT(0);
/* will never happen */
break;
}
}

Expand Down Expand Up @@ -946,8 +941,9 @@ static int set_module_break(Module *modp, Eterm mfa[3], int specified,
static int set_function_break(Module *modp, BeamInstr *pc,
Binary *match_spec, BeamInstr break_op,
enum erts_break_op count_op, Eterm tracer_pid) {
BpData *bd, **r;
BpData *bd, **r, ***rs;
size_t size;
Uint ix = 0;
BeamInstr **code_base = (BeamInstr **)modp->code;

ASSERT(code_base);
Expand Down Expand Up @@ -1037,7 +1033,15 @@ static int set_function_break(Module *modp, BeamInstr *pc,
size = sizeof(BpDataDebug);
}
}
r = (BpData **) (pc-4);
rs = (BpData ***) (pc-4);
if (! *rs) {
size_t ssize = sizeof(BeamInstr) * erts_no_schedulers;
*rs = (BpData **) Alloc(ssize);
sys_memzero(*rs, ssize);
}

r = &((*rs)[0]);

if (! *r) {
ASSERT(*pc != (BeamInstr) BeamOp(op_i_trace_breakpoint));
ASSERT(*pc != (BeamInstr) BeamOp(op_i_mtrace_breakpoint));
Expand All @@ -1058,12 +1062,12 @@ static int set_function_break(Module *modp, BeamInstr *pc,
if (*pc == (BeamInstr) BeamOp(op_i_debug_breakpoint)) {
/* Debug bp must be last, so if it is also first;
* it must be singleton. */
ASSERT(BpSingleton(*r));
ASSERT(BpSingleton(*r));
/* Insert new bp first in the ring, i.e second to last. */
bd = Alloc(size);
BpInitAndSpliceNext(bd, *pc, *r);
*pc = break_op;
} else if ((*r)->prev->orig_instr
} else if ((*r)->prev->orig_instr
== (BeamInstr) BeamOp(op_i_debug_breakpoint)) {
/* Debug bp last in the ring; insert new second to last. */
bd = Alloc(size);
Expand All @@ -1077,6 +1081,10 @@ static int set_function_break(Module *modp, BeamInstr *pc,
*r = bd;
}
}
for (ix = 1; ix < erts_no_schedulers; ++ix) {
(*rs)[ix] = (*rs)[0];
}

bd->this_instr = break_op;
/* Init the bp type specific data */
if (break_op == (BeamInstr) BeamOp(op_i_trace_breakpoint) ||
Expand Down Expand Up @@ -1161,6 +1169,7 @@ static int clear_module_break(Module *m, Eterm mfa[3], int specified,

static int clear_function_break(Module *m, BeamInstr *pc, BeamInstr break_op) {
BpData *bd;
Uint ix = 0;
BeamInstr **code_base = (BeamInstr **)m->code;

ASSERT(code_base);
Expand All @@ -1178,8 +1187,17 @@ static int clear_function_break(Module *m, BeamInstr *pc, BeamInstr break_op) {
* but break_op may be 0 which matches any type.
*/
BeamInstr op;
BpData **r = (BpData **) (pc-4);
BpData ***rs = (BpData ***) (pc - 4);
BpData **r = NULL;

#ifdef DEBUG
for (ix = 1; ix < erts_no_schedulers; ++ix) {
ASSERT((*rs)[ix] == (*rs)[0]);
}
#endif

r = &((*rs)[0]);

ASSERT(*r);
/* Find opcode for this breakpoint */
if (break_op) {
Expand All @@ -1195,8 +1213,9 @@ static int clear_function_break(Module *m, BeamInstr *pc, BeamInstr break_op) {
if (BpSingleton(bd)) {
ASSERT(*r == bd);
/* Only one breakpoint to remove */
*r = NULL;
*pc = bd->orig_instr;
Free(*rs);
*rs = NULL;
} else {
BpData *bd_prev = bd->prev;

Expand Down Expand Up @@ -1256,7 +1275,12 @@ static int clear_function_break(Module *m, BeamInstr *pc, BeamInstr break_op) {
Free(bd);
ASSERT(((BeamInstr) code_base[MI_NUM_BREAKPOINTS]) > 0);
--(*(BeamInstr*)&code_base[MI_NUM_BREAKPOINTS]);
}
if (*rs) {
for (ix = 1; ix < erts_no_schedulers; ++ix) {
(*rs)[ix] = (*rs)[0];
}
}
} /* while bd != NULL */
return 1;
}

Expand All @@ -1272,7 +1296,16 @@ static int clear_function_break(Module *m, BeamInstr *pc, BeamInstr break_op) {
static BpData *is_break(BeamInstr *pc, BeamInstr break_op) {
ASSERT(pc[-5] == (BeamInstr) BeamOp(op_i_func_info_IaaI));
if (! erts_is_native_break(pc)) {
BpData *bd = (BpData *) pc[-4];
BpData **rs = (BpData **) pc[-4];
BpData *bd = NULL, *ebd = NULL;

if (! rs) {
return NULL;
}

bd = ebd = rs[bp_sched2ix()];

ASSERT(bd);

if (break_op == 0) {
return bd;
Expand All @@ -1285,7 +1318,7 @@ static BpData *is_break(BeamInstr *pc, BeamInstr break_op) {
return NULL;
}
bd = bd->next;
while (bd != (BpData *) pc[-4]) {
while (bd != ebd) {
ASSERT(bd);
if (bd->orig_instr == break_op) {
bd = bd->next;
Expand All @@ -1298,17 +1331,24 @@ static BpData *is_break(BeamInstr *pc, BeamInstr break_op) {
}
return NULL;
}
static BpData *get_break(BeamInstr *pc, BeamInstr break_op) {
static BpData *get_break(Process *p, BeamInstr *pc, BeamInstr break_op) {
ASSERT(pc[-5] == (BeamInstr) BeamOp(op_i_func_info_IaaI));
if (! erts_is_native_break(pc)) {
BpData *bd = (BpData *) pc[-4];
BpData **rs = (BpData **) pc[-4];
BpData *bd = NULL, *ebd = NULL;

if (! bd){
if (! rs) {
return NULL;
}

bd = ebd = rs[bp_sched2ix_proc(p)];
ASSERT(bd);
if (bd->this_instr == break_op) {
return bd;
}

bd = bd->next;
while (bd != (BpData *) pc[-4]) {
while (bd != ebd) {
ASSERT(bd);
if (bd->this_instr == break_op) {
ASSERT(bd);
Expand Down

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