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kmp_barrier.cpp
1797 lines (1665 loc) · 85.1 KB
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kmp_barrier.cpp
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/*
* kmp_barrier.cpp
*/
//===----------------------------------------------------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is dual licensed under the MIT and the University of Illinois Open
// Source Licenses. See LICENSE.txt for details.
//
//===----------------------------------------------------------------------===//
#include "kmp.h"
#include "kmp_wait_release.h"
#include "kmp_stats.h"
#include "kmp_itt.h"
#include "kmp_os.h"
#if KMP_MIC
#include <immintrin.h>
#define USE_NGO_STORES 1
#endif // KMP_MIC
#include "tsan_annotations.h"
#if KMP_MIC && USE_NGO_STORES
// ICV copying
#define ngo_load(src) __m512d Vt = _mm512_load_pd((void *)(src))
#define ngo_store_icvs(dst, src) _mm512_storenrngo_pd((void *)(dst), Vt)
#define ngo_store_go(dst, src) _mm512_storenrngo_pd((void *)(dst), Vt)
#define ngo_sync() __asm__ volatile ("lock; addl $0,0(%%rsp)" ::: "memory")
#else
#define ngo_load(src) ((void)0)
#define ngo_store_icvs(dst, src) copy_icvs((dst), (src))
#define ngo_store_go(dst, src) KMP_MEMCPY((dst), (src), CACHE_LINE)
#define ngo_sync() ((void)0)
#endif /* KMP_MIC && USE_NGO_STORES */
void __kmp_print_structure(void); // Forward declaration
// ---------------------------- Barrier Algorithms ----------------------------
// Linear Barrier
static void
__kmp_linear_barrier_gather(enum barrier_type bt, kmp_info_t *this_thr, int gtid, int tid,
void (*reduce)(void *, void *)
USE_ITT_BUILD_ARG(void * itt_sync_obj) )
{
KMP_TIME_DEVELOPER_PARTITIONED_BLOCK(KMP_linear_gather);
register kmp_team_t *team = this_thr->th.th_team;
register kmp_bstate_t *thr_bar = & this_thr->th.th_bar[bt].bb;
register kmp_info_t **other_threads = team->t.t_threads;
KA_TRACE(20, ("__kmp_linear_barrier_gather: T#%d(%d:%d) enter for barrier type %d\n",
gtid, team->t.t_id, tid, bt));
KMP_DEBUG_ASSERT(this_thr == other_threads[this_thr->th.th_info.ds.ds_tid]);
#if USE_ITT_BUILD && USE_ITT_NOTIFY
// Barrier imbalance - save arrive time to the thread
if(__kmp_forkjoin_frames_mode == 3 || __kmp_forkjoin_frames_mode == 2) {
this_thr->th.th_bar_arrive_time = this_thr->th.th_bar_min_time = __itt_get_timestamp();
}
#endif
// We now perform a linear reduction to signal that all of the threads have arrived.
if (!KMP_MASTER_TID(tid)) {
KA_TRACE(20, ("__kmp_linear_barrier_gather: T#%d(%d:%d) releasing T#%d(%d:%d)"
"arrived(%p): %llu => %llu\n", gtid, team->t.t_id, tid,
__kmp_gtid_from_tid(0, team), team->t.t_id, 0, &thr_bar->b_arrived,
thr_bar->b_arrived, thr_bar->b_arrived + KMP_BARRIER_STATE_BUMP));
// Mark arrival to master thread
/* After performing this write, a worker thread may not assume that the team is valid
any more - it could be deallocated by the master thread at any time. */
kmp_flag_64 flag(&thr_bar->b_arrived, other_threads[0]);
flag.release();
} else {
register kmp_balign_team_t *team_bar = &team->t.t_bar[bt];
register int nproc = this_thr->th.th_team_nproc;
register int i;
// Don't have to worry about sleep bit here or atomic since team setting
register kmp_uint64 new_state = team_bar->b_arrived + KMP_BARRIER_STATE_BUMP;
// Collect all the worker team member threads.
for (i=1; i<nproc; ++i) {
#if KMP_CACHE_MANAGE
// Prefetch next thread's arrived count
if (i+1 < nproc)
KMP_CACHE_PREFETCH(&other_threads[i+1]->th.th_bar[bt].bb.b_arrived);
#endif /* KMP_CACHE_MANAGE */
KA_TRACE(20, ("__kmp_linear_barrier_gather: T#%d(%d:%d) wait T#%d(%d:%d) "
"arrived(%p) == %llu\n", gtid, team->t.t_id, tid,
__kmp_gtid_from_tid(i, team), team->t.t_id, i,
&other_threads[i]->th.th_bar[bt].bb.b_arrived, new_state));
// Wait for worker thread to arrive
kmp_flag_64 flag(&other_threads[i]->th.th_bar[bt].bb.b_arrived, new_state);
flag.wait(this_thr, FALSE
USE_ITT_BUILD_ARG(itt_sync_obj) );
#if USE_ITT_BUILD && USE_ITT_NOTIFY
// Barrier imbalance - write min of the thread time and the other thread time to the thread.
if (__kmp_forkjoin_frames_mode == 2) {
this_thr->th.th_bar_min_time = KMP_MIN(this_thr->th.th_bar_min_time,
other_threads[i]->th.th_bar_min_time);
}
#endif
if (reduce) {
KA_TRACE(100, ("__kmp_linear_barrier_gather: T#%d(%d:%d) += T#%d(%d:%d)\n", gtid,
team->t.t_id, tid, __kmp_gtid_from_tid(i, team), team->t.t_id, i));
ANNOTATE_REDUCE_AFTER(reduce);
(*reduce)(this_thr->th.th_local.reduce_data,
other_threads[i]->th.th_local.reduce_data);
ANNOTATE_REDUCE_BEFORE(reduce);
ANNOTATE_REDUCE_BEFORE(&team->t.t_bar);
}
}
// Don't have to worry about sleep bit here or atomic since team setting
team_bar->b_arrived = new_state;
KA_TRACE(20, ("__kmp_linear_barrier_gather: T#%d(%d:%d) set team %d arrived(%p) = %llu\n",
gtid, team->t.t_id, tid, team->t.t_id, &team_bar->b_arrived, new_state));
}
KA_TRACE(20, ("__kmp_linear_barrier_gather: T#%d(%d:%d) exit for barrier type %d\n",
gtid, team->t.t_id, tid, bt));
}
static void
__kmp_linear_barrier_release(enum barrier_type bt, kmp_info_t *this_thr, int gtid, int tid,
int propagate_icvs
USE_ITT_BUILD_ARG(void *itt_sync_obj) )
{
KMP_TIME_DEVELOPER_PARTITIONED_BLOCK(KMP_linear_release);
register kmp_bstate_t *thr_bar = &this_thr->th.th_bar[bt].bb;
register kmp_team_t *team;
if (KMP_MASTER_TID(tid)) {
register unsigned int i;
register kmp_uint32 nproc = this_thr->th.th_team_nproc;
register kmp_info_t **other_threads;
team = __kmp_threads[gtid]->th.th_team;
KMP_DEBUG_ASSERT(team != NULL);
other_threads = team->t.t_threads;
KA_TRACE(20, ("__kmp_linear_barrier_release: T#%d(%d:%d) master enter for barrier type %d\n",
gtid, team->t.t_id, tid, bt));
if (nproc > 1) {
#if KMP_BARRIER_ICV_PUSH
{
KMP_TIME_DEVELOPER_PARTITIONED_BLOCK(USER_icv_copy);
if (propagate_icvs) {
ngo_load(&team->t.t_implicit_task_taskdata[0].td_icvs);
for (i=1; i<nproc; ++i) {
__kmp_init_implicit_task(team->t.t_ident, team->t.t_threads[i], team, i, FALSE);
ngo_store_icvs(&team->t.t_implicit_task_taskdata[i].td_icvs,
&team->t.t_implicit_task_taskdata[0].td_icvs);
}
ngo_sync();
}
}
#endif // KMP_BARRIER_ICV_PUSH
// Now, release all of the worker threads
for (i=1; i<nproc; ++i) {
#if KMP_CACHE_MANAGE
// Prefetch next thread's go flag
if (i+1 < nproc)
KMP_CACHE_PREFETCH(&other_threads[i+1]->th.th_bar[bt].bb.b_go);
#endif /* KMP_CACHE_MANAGE */
KA_TRACE(20, ("__kmp_linear_barrier_release: T#%d(%d:%d) releasing T#%d(%d:%d) "
"go(%p): %u => %u\n", gtid, team->t.t_id, tid,
other_threads[i]->th.th_info.ds.ds_gtid, team->t.t_id, i,
&other_threads[i]->th.th_bar[bt].bb.b_go,
other_threads[i]->th.th_bar[bt].bb.b_go,
other_threads[i]->th.th_bar[bt].bb.b_go + KMP_BARRIER_STATE_BUMP));
kmp_flag_64 flag(&other_threads[i]->th.th_bar[bt].bb.b_go, other_threads[i]);
flag.release();
}
}
} else { // Wait for the MASTER thread to release us
KA_TRACE(20, ("__kmp_linear_barrier_release: T#%d wait go(%p) == %u\n",
gtid, &thr_bar->b_go, KMP_BARRIER_STATE_BUMP));
kmp_flag_64 flag(&thr_bar->b_go, KMP_BARRIER_STATE_BUMP);
flag.wait(this_thr, TRUE
USE_ITT_BUILD_ARG(itt_sync_obj) );
#if USE_ITT_BUILD && USE_ITT_NOTIFY
if ((__itt_sync_create_ptr && itt_sync_obj == NULL) || KMP_ITT_DEBUG) {
// In a fork barrier; cannot get the object reliably (or ITTNOTIFY is disabled)
itt_sync_obj = __kmp_itt_barrier_object(gtid, bs_forkjoin_barrier, 0, -1);
// Cancel wait on previous parallel region...
__kmp_itt_task_starting(itt_sync_obj);
if (bt == bs_forkjoin_barrier && TCR_4(__kmp_global.g.g_done))
return;
itt_sync_obj = __kmp_itt_barrier_object(gtid, bs_forkjoin_barrier);
if (itt_sync_obj != NULL)
// Call prepare as early as possible for "new" barrier
__kmp_itt_task_finished(itt_sync_obj);
} else
#endif /* USE_ITT_BUILD && USE_ITT_NOTIFY */
// Early exit for reaping threads releasing forkjoin barrier
if ( bt == bs_forkjoin_barrier && TCR_4(__kmp_global.g.g_done) )
return;
// The worker thread may now assume that the team is valid.
#ifdef KMP_DEBUG
tid = __kmp_tid_from_gtid(gtid);
team = __kmp_threads[gtid]->th.th_team;
#endif
KMP_DEBUG_ASSERT(team != NULL);
TCW_4(thr_bar->b_go, KMP_INIT_BARRIER_STATE);
KA_TRACE(20, ("__kmp_linear_barrier_release: T#%d(%d:%d) set go(%p) = %u\n",
gtid, team->t.t_id, tid, &thr_bar->b_go, KMP_INIT_BARRIER_STATE));
KMP_MB(); // Flush all pending memory write invalidates.
}
KA_TRACE(20, ("__kmp_linear_barrier_release: T#%d(%d:%d) exit for barrier type %d\n",
gtid, team->t.t_id, tid, bt));
}
// Tree barrier
static void
__kmp_tree_barrier_gather(enum barrier_type bt, kmp_info_t *this_thr, int gtid, int tid,
void (*reduce)(void *, void *)
USE_ITT_BUILD_ARG(void *itt_sync_obj) )
{
KMP_TIME_DEVELOPER_PARTITIONED_BLOCK(KMP_tree_gather);
register kmp_team_t *team = this_thr->th.th_team;
register kmp_bstate_t *thr_bar = &this_thr->th.th_bar[bt].bb;
register kmp_info_t **other_threads = team->t.t_threads;
register kmp_uint32 nproc = this_thr->th.th_team_nproc;
register kmp_uint32 branch_bits = __kmp_barrier_gather_branch_bits[bt];
register kmp_uint32 branch_factor = 1 << branch_bits;
register kmp_uint32 child;
register kmp_uint32 child_tid;
register kmp_uint64 new_state;
KA_TRACE(20, ("__kmp_tree_barrier_gather: T#%d(%d:%d) enter for barrier type %d\n",
gtid, team->t.t_id, tid, bt));
KMP_DEBUG_ASSERT(this_thr == other_threads[this_thr->th.th_info.ds.ds_tid]);
#if USE_ITT_BUILD && USE_ITT_NOTIFY
// Barrier imbalance - save arrive time to the thread
if(__kmp_forkjoin_frames_mode == 3 || __kmp_forkjoin_frames_mode == 2) {
this_thr->th.th_bar_arrive_time = this_thr->th.th_bar_min_time = __itt_get_timestamp();
}
#endif
// Perform tree gather to wait until all threads have arrived; reduce any required data as we go
child_tid = (tid << branch_bits) + 1;
if (child_tid < nproc) {
// Parent threads wait for all their children to arrive
new_state = team->t.t_bar[bt].b_arrived + KMP_BARRIER_STATE_BUMP;
child = 1;
do {
register kmp_info_t *child_thr = other_threads[child_tid];
register kmp_bstate_t *child_bar = &child_thr->th.th_bar[bt].bb;
#if KMP_CACHE_MANAGE
// Prefetch next thread's arrived count
if (child+1 <= branch_factor && child_tid+1 < nproc)
KMP_CACHE_PREFETCH(&other_threads[child_tid+1]->th.th_bar[bt].bb.b_arrived);
#endif /* KMP_CACHE_MANAGE */
KA_TRACE(20, ("__kmp_tree_barrier_gather: T#%d(%d:%d) wait T#%d(%d:%u) "
"arrived(%p) == %llu\n", gtid, team->t.t_id, tid,
__kmp_gtid_from_tid(child_tid, team), team->t.t_id, child_tid,
&child_bar->b_arrived, new_state));
// Wait for child to arrive
kmp_flag_64 flag(&child_bar->b_arrived, new_state);
flag.wait(this_thr, FALSE
USE_ITT_BUILD_ARG(itt_sync_obj) );
#if USE_ITT_BUILD && USE_ITT_NOTIFY
// Barrier imbalance - write min of the thread time and a child time to the thread.
if (__kmp_forkjoin_frames_mode == 2) {
this_thr->th.th_bar_min_time = KMP_MIN(this_thr->th.th_bar_min_time,
child_thr->th.th_bar_min_time);
}
#endif
if (reduce) {
KA_TRACE(100, ("__kmp_tree_barrier_gather: T#%d(%d:%d) += T#%d(%d:%u)\n",
gtid, team->t.t_id, tid, __kmp_gtid_from_tid(child_tid, team),
team->t.t_id, child_tid));
ANNOTATE_REDUCE_AFTER(reduce);
(*reduce)(this_thr->th.th_local.reduce_data, child_thr->th.th_local.reduce_data);
ANNOTATE_REDUCE_BEFORE(reduce);
ANNOTATE_REDUCE_BEFORE(&team->t.t_bar);
}
child++;
child_tid++;
}
while (child <= branch_factor && child_tid < nproc);
}
if (!KMP_MASTER_TID(tid)) { // Worker threads
register kmp_int32 parent_tid = (tid - 1) >> branch_bits;
KA_TRACE(20, ("__kmp_tree_barrier_gather: T#%d(%d:%d) releasing T#%d(%d:%d) "
"arrived(%p): %llu => %llu\n", gtid, team->t.t_id, tid,
__kmp_gtid_from_tid(parent_tid, team), team->t.t_id, parent_tid,
&thr_bar->b_arrived, thr_bar->b_arrived,
thr_bar->b_arrived + KMP_BARRIER_STATE_BUMP));
// Mark arrival to parent thread
/* After performing this write, a worker thread may not assume that the team is valid
any more - it could be deallocated by the master thread at any time. */
kmp_flag_64 flag(&thr_bar->b_arrived, other_threads[parent_tid]);
flag.release();
} else {
// Need to update the team arrived pointer if we are the master thread
if (nproc > 1) // New value was already computed above
team->t.t_bar[bt].b_arrived = new_state;
else
team->t.t_bar[bt].b_arrived += KMP_BARRIER_STATE_BUMP;
KA_TRACE(20, ("__kmp_tree_barrier_gather: T#%d(%d:%d) set team %d arrived(%p) = %llu\n",
gtid, team->t.t_id, tid, team->t.t_id,
&team->t.t_bar[bt].b_arrived, team->t.t_bar[bt].b_arrived));
}
KA_TRACE(20, ("__kmp_tree_barrier_gather: T#%d(%d:%d) exit for barrier type %d\n",
gtid, team->t.t_id, tid, bt));
}
static void
__kmp_tree_barrier_release(enum barrier_type bt, kmp_info_t *this_thr, int gtid, int tid,
int propagate_icvs
USE_ITT_BUILD_ARG(void *itt_sync_obj) )
{
KMP_TIME_DEVELOPER_PARTITIONED_BLOCK(KMP_tree_release);
register kmp_team_t *team;
register kmp_bstate_t *thr_bar = &this_thr->th.th_bar[bt].bb;
register kmp_uint32 nproc;
register kmp_uint32 branch_bits = __kmp_barrier_release_branch_bits[bt];
register kmp_uint32 branch_factor = 1 << branch_bits;
register kmp_uint32 child;
register kmp_uint32 child_tid;
// Perform a tree release for all of the threads that have been gathered
if (!KMP_MASTER_TID(tid)) { // Handle fork barrier workers who aren't part of a team yet
KA_TRACE(20, ("__kmp_tree_barrier_release: T#%d wait go(%p) == %u\n",
gtid, &thr_bar->b_go, KMP_BARRIER_STATE_BUMP));
// Wait for parent thread to release us
kmp_flag_64 flag(&thr_bar->b_go, KMP_BARRIER_STATE_BUMP);
flag.wait(this_thr, TRUE
USE_ITT_BUILD_ARG(itt_sync_obj) );
#if USE_ITT_BUILD && USE_ITT_NOTIFY
if ((__itt_sync_create_ptr && itt_sync_obj == NULL) || KMP_ITT_DEBUG) {
// In fork barrier where we could not get the object reliably (or ITTNOTIFY is disabled)
itt_sync_obj = __kmp_itt_barrier_object(gtid, bs_forkjoin_barrier, 0, -1);
// Cancel wait on previous parallel region...
__kmp_itt_task_starting(itt_sync_obj);
if (bt == bs_forkjoin_barrier && TCR_4(__kmp_global.g.g_done))
return;
itt_sync_obj = __kmp_itt_barrier_object(gtid, bs_forkjoin_barrier);
if (itt_sync_obj != NULL)
// Call prepare as early as possible for "new" barrier
__kmp_itt_task_finished(itt_sync_obj);
} else
#endif /* USE_ITT_BUILD && USE_ITT_NOTIFY */
// Early exit for reaping threads releasing forkjoin barrier
if (bt == bs_forkjoin_barrier && TCR_4(__kmp_global.g.g_done))
return;
// The worker thread may now assume that the team is valid.
team = __kmp_threads[gtid]->th.th_team;
KMP_DEBUG_ASSERT(team != NULL);
tid = __kmp_tid_from_gtid(gtid);
TCW_4(thr_bar->b_go, KMP_INIT_BARRIER_STATE);
KA_TRACE(20, ("__kmp_tree_barrier_release: T#%d(%d:%d) set go(%p) = %u\n",
gtid, team->t.t_id, tid, &thr_bar->b_go, KMP_INIT_BARRIER_STATE));
KMP_MB(); // Flush all pending memory write invalidates.
} else {
team = __kmp_threads[gtid]->th.th_team;
KMP_DEBUG_ASSERT(team != NULL);
KA_TRACE(20, ("__kmp_tree_barrier_release: T#%d(%d:%d) master enter for barrier type %d\n",
gtid, team->t.t_id, tid, bt));
}
nproc = this_thr->th.th_team_nproc;
child_tid = (tid << branch_bits) + 1;
if (child_tid < nproc) {
register kmp_info_t **other_threads = team->t.t_threads;
child = 1;
// Parent threads release all their children
do {
register kmp_info_t *child_thr = other_threads[child_tid];
register kmp_bstate_t *child_bar = &child_thr->th.th_bar[bt].bb;
#if KMP_CACHE_MANAGE
// Prefetch next thread's go count
if (child+1 <= branch_factor && child_tid+1 < nproc)
KMP_CACHE_PREFETCH(&other_threads[child_tid+1]->th.th_bar[bt].bb.b_go);
#endif /* KMP_CACHE_MANAGE */
#if KMP_BARRIER_ICV_PUSH
{
KMP_TIME_DEVELOPER_PARTITIONED_BLOCK(USER_icv_copy);
if (propagate_icvs) {
__kmp_init_implicit_task(team->t.t_ident, team->t.t_threads[child_tid],
team, child_tid, FALSE);
copy_icvs(&team->t.t_implicit_task_taskdata[child_tid].td_icvs,
&team->t.t_implicit_task_taskdata[0].td_icvs);
}
}
#endif // KMP_BARRIER_ICV_PUSH
KA_TRACE(20, ("__kmp_tree_barrier_release: T#%d(%d:%d) releasing T#%d(%d:%u)"
"go(%p): %u => %u\n", gtid, team->t.t_id, tid,
__kmp_gtid_from_tid(child_tid, team), team->t.t_id,
child_tid, &child_bar->b_go, child_bar->b_go,
child_bar->b_go + KMP_BARRIER_STATE_BUMP));
// Release child from barrier
kmp_flag_64 flag(&child_bar->b_go, child_thr);
flag.release();
child++;
child_tid++;
}
while (child <= branch_factor && child_tid < nproc);
}
KA_TRACE(20, ("__kmp_tree_barrier_release: T#%d(%d:%d) exit for barrier type %d\n",
gtid, team->t.t_id, tid, bt));
}
// Hyper Barrier
static void
__kmp_hyper_barrier_gather(enum barrier_type bt, kmp_info_t *this_thr, int gtid, int tid,
void (*reduce)(void *, void *)
USE_ITT_BUILD_ARG(void *itt_sync_obj) )
{
KMP_TIME_DEVELOPER_PARTITIONED_BLOCK(KMP_hyper_gather);
register kmp_team_t *team = this_thr->th.th_team;
register kmp_bstate_t *thr_bar = &this_thr->th.th_bar[bt].bb;
register kmp_info_t **other_threads = team->t.t_threads;
register kmp_uint64 new_state = KMP_BARRIER_UNUSED_STATE;
register kmp_uint32 num_threads = this_thr->th.th_team_nproc;
register kmp_uint32 branch_bits = __kmp_barrier_gather_branch_bits[bt];
register kmp_uint32 branch_factor = 1 << branch_bits;
register kmp_uint32 offset;
register kmp_uint32 level;
KA_TRACE(20, ("__kmp_hyper_barrier_gather: T#%d(%d:%d) enter for barrier type %d\n",
gtid, team->t.t_id, tid, bt));
KMP_DEBUG_ASSERT(this_thr == other_threads[this_thr->th.th_info.ds.ds_tid]);
#if USE_ITT_BUILD && USE_ITT_NOTIFY
// Barrier imbalance - save arrive time to the thread
if(__kmp_forkjoin_frames_mode == 3 || __kmp_forkjoin_frames_mode == 2) {
this_thr->th.th_bar_arrive_time = this_thr->th.th_bar_min_time = __itt_get_timestamp();
}
#endif
/* Perform a hypercube-embedded tree gather to wait until all of the threads have
arrived, and reduce any required data as we go. */
kmp_flag_64 p_flag(&thr_bar->b_arrived);
for (level=0, offset=1; offset<num_threads; level+=branch_bits, offset<<=branch_bits)
{
register kmp_uint32 child;
register kmp_uint32 child_tid;
if (((tid >> level) & (branch_factor - 1)) != 0) {
register kmp_int32 parent_tid = tid & ~((1 << (level + branch_bits)) -1);
KA_TRACE(20, ("__kmp_hyper_barrier_gather: T#%d(%d:%d) releasing T#%d(%d:%d) "
"arrived(%p): %llu => %llu\n", gtid, team->t.t_id, tid,
__kmp_gtid_from_tid(parent_tid, team), team->t.t_id, parent_tid,
&thr_bar->b_arrived, thr_bar->b_arrived,
thr_bar->b_arrived + KMP_BARRIER_STATE_BUMP));
// Mark arrival to parent thread
/* After performing this write (in the last iteration of the enclosing for loop),
a worker thread may not assume that the team is valid any more - it could be
deallocated by the master thread at any time. */
p_flag.set_waiter(other_threads[parent_tid]);
p_flag.release();
break;
}
// Parent threads wait for children to arrive
if (new_state == KMP_BARRIER_UNUSED_STATE)
new_state = team->t.t_bar[bt].b_arrived + KMP_BARRIER_STATE_BUMP;
for (child=1, child_tid=tid+(1 << level); child<branch_factor && child_tid<num_threads;
child++, child_tid+=(1 << level))
{
register kmp_info_t *child_thr = other_threads[child_tid];
register kmp_bstate_t *child_bar = &child_thr->th.th_bar[bt].bb;
#if KMP_CACHE_MANAGE
register kmp_uint32 next_child_tid = child_tid + (1 << level);
// Prefetch next thread's arrived count
if (child+1 < branch_factor && next_child_tid < num_threads)
KMP_CACHE_PREFETCH(&other_threads[next_child_tid]->th.th_bar[bt].bb.b_arrived);
#endif /* KMP_CACHE_MANAGE */
KA_TRACE(20, ("__kmp_hyper_barrier_gather: T#%d(%d:%d) wait T#%d(%d:%u) "
"arrived(%p) == %llu\n", gtid, team->t.t_id, tid,
__kmp_gtid_from_tid(child_tid, team), team->t.t_id, child_tid,
&child_bar->b_arrived, new_state));
// Wait for child to arrive
kmp_flag_64 c_flag(&child_bar->b_arrived, new_state);
c_flag.wait(this_thr, FALSE
USE_ITT_BUILD_ARG(itt_sync_obj) );
#if USE_ITT_BUILD && USE_ITT_NOTIFY
// Barrier imbalance - write min of the thread time and a child time to the thread.
if (__kmp_forkjoin_frames_mode == 2) {
this_thr->th.th_bar_min_time = KMP_MIN(this_thr->th.th_bar_min_time,
child_thr->th.th_bar_min_time);
}
#endif
if (reduce) {
KA_TRACE(100, ("__kmp_hyper_barrier_gather: T#%d(%d:%d) += T#%d(%d:%u)\n",
gtid, team->t.t_id, tid, __kmp_gtid_from_tid(child_tid, team),
team->t.t_id, child_tid));
ANNOTATE_REDUCE_AFTER(reduce);
(*reduce)(this_thr->th.th_local.reduce_data, child_thr->th.th_local.reduce_data);
ANNOTATE_REDUCE_BEFORE(reduce);
ANNOTATE_REDUCE_BEFORE(&team->t.t_bar);
}
}
}
if (KMP_MASTER_TID(tid)) {
// Need to update the team arrived pointer if we are the master thread
if (new_state == KMP_BARRIER_UNUSED_STATE)
team->t.t_bar[bt].b_arrived += KMP_BARRIER_STATE_BUMP;
else
team->t.t_bar[bt].b_arrived = new_state;
KA_TRACE(20, ("__kmp_hyper_barrier_gather: T#%d(%d:%d) set team %d arrived(%p) = %llu\n",
gtid, team->t.t_id, tid, team->t.t_id,
&team->t.t_bar[bt].b_arrived, team->t.t_bar[bt].b_arrived));
}
KA_TRACE(20, ("__kmp_hyper_barrier_gather: T#%d(%d:%d) exit for barrier type %d\n",
gtid, team->t.t_id, tid, bt));
}
// The reverse versions seem to beat the forward versions overall
#define KMP_REVERSE_HYPER_BAR
static void
__kmp_hyper_barrier_release(enum barrier_type bt, kmp_info_t *this_thr, int gtid, int tid,
int propagate_icvs
USE_ITT_BUILD_ARG(void *itt_sync_obj) )
{
KMP_TIME_DEVELOPER_PARTITIONED_BLOCK(KMP_hyper_release);
register kmp_team_t *team;
register kmp_bstate_t *thr_bar = & this_thr -> th.th_bar[ bt ].bb;
register kmp_info_t **other_threads;
register kmp_uint32 num_threads;
register kmp_uint32 branch_bits = __kmp_barrier_release_branch_bits[ bt ];
register kmp_uint32 branch_factor = 1 << branch_bits;
register kmp_uint32 child;
register kmp_uint32 child_tid;
register kmp_uint32 offset;
register kmp_uint32 level;
/* Perform a hypercube-embedded tree release for all of the threads that have been gathered.
If KMP_REVERSE_HYPER_BAR is defined (default) the threads are released in the reverse
order of the corresponding gather, otherwise threads are released in the same order. */
if (KMP_MASTER_TID(tid)) { // master
team = __kmp_threads[gtid]->th.th_team;
KMP_DEBUG_ASSERT(team != NULL);
KA_TRACE(20, ("__kmp_hyper_barrier_release: T#%d(%d:%d) master enter for barrier type %d\n",
gtid, team->t.t_id, tid, bt));
#if KMP_BARRIER_ICV_PUSH
if (propagate_icvs) { // master already has ICVs in final destination; copy
copy_icvs(&thr_bar->th_fixed_icvs, &team->t.t_implicit_task_taskdata[tid].td_icvs);
}
#endif
}
else { // Handle fork barrier workers who aren't part of a team yet
KA_TRACE(20, ("__kmp_hyper_barrier_release: T#%d wait go(%p) == %u\n",
gtid, &thr_bar->b_go, KMP_BARRIER_STATE_BUMP));
// Wait for parent thread to release us
kmp_flag_64 flag(&thr_bar->b_go, KMP_BARRIER_STATE_BUMP);
flag.wait(this_thr, TRUE
USE_ITT_BUILD_ARG(itt_sync_obj) );
#if USE_ITT_BUILD && USE_ITT_NOTIFY
if ((__itt_sync_create_ptr && itt_sync_obj == NULL) || KMP_ITT_DEBUG) {
// In fork barrier where we could not get the object reliably
itt_sync_obj = __kmp_itt_barrier_object(gtid, bs_forkjoin_barrier, 0, -1);
// Cancel wait on previous parallel region...
__kmp_itt_task_starting(itt_sync_obj);
if (bt == bs_forkjoin_barrier && TCR_4(__kmp_global.g.g_done))
return;
itt_sync_obj = __kmp_itt_barrier_object(gtid, bs_forkjoin_barrier);
if (itt_sync_obj != NULL)
// Call prepare as early as possible for "new" barrier
__kmp_itt_task_finished(itt_sync_obj);
} else
#endif /* USE_ITT_BUILD && USE_ITT_NOTIFY */
// Early exit for reaping threads releasing forkjoin barrier
if (bt == bs_forkjoin_barrier && TCR_4(__kmp_global.g.g_done))
return;
// The worker thread may now assume that the team is valid.
team = __kmp_threads[gtid]->th.th_team;
KMP_DEBUG_ASSERT(team != NULL);
tid = __kmp_tid_from_gtid(gtid);
TCW_4(thr_bar->b_go, KMP_INIT_BARRIER_STATE);
KA_TRACE(20, ("__kmp_hyper_barrier_release: T#%d(%d:%d) set go(%p) = %u\n",
gtid, team->t.t_id, tid, &thr_bar->b_go, KMP_INIT_BARRIER_STATE));
KMP_MB(); // Flush all pending memory write invalidates.
}
num_threads = this_thr->th.th_team_nproc;
other_threads = team->t.t_threads;
#ifdef KMP_REVERSE_HYPER_BAR
// Count up to correct level for parent
for (level=0, offset=1; offset<num_threads && (((tid>>level) & (branch_factor-1)) == 0);
level+=branch_bits, offset<<=branch_bits);
// Now go down from there
for (level-=branch_bits, offset>>=branch_bits; offset != 0;
level-=branch_bits, offset>>=branch_bits)
#else
// Go down the tree, level by level
for (level=0, offset=1; offset<num_threads; level+=branch_bits, offset<<=branch_bits)
#endif // KMP_REVERSE_HYPER_BAR
{
#ifdef KMP_REVERSE_HYPER_BAR
/* Now go in reverse order through the children, highest to lowest.
Initial setting of child is conservative here. */
child = num_threads >> ((level==0)?level:level-1);
for (child=(child<branch_factor-1) ? child : branch_factor-1, child_tid=tid+(child<<level);
child>=1; child--, child_tid-=(1<<level))
#else
if (((tid >> level) & (branch_factor - 1)) != 0)
// No need to go lower than this, since this is the level parent would be notified
break;
// Iterate through children on this level of the tree
for (child=1, child_tid=tid+(1<<level); child<branch_factor && child_tid<num_threads;
child++, child_tid+=(1<<level))
#endif // KMP_REVERSE_HYPER_BAR
{
if (child_tid >= num_threads) continue; // Child doesn't exist so keep going
else {
register kmp_info_t *child_thr = other_threads[child_tid];
register kmp_bstate_t *child_bar = &child_thr->th.th_bar[bt].bb;
#if KMP_CACHE_MANAGE
register kmp_uint32 next_child_tid = child_tid - (1 << level);
// Prefetch next thread's go count
# ifdef KMP_REVERSE_HYPER_BAR
if (child-1 >= 1 && next_child_tid < num_threads)
# else
if (child+1 < branch_factor && next_child_tid < num_threads)
# endif // KMP_REVERSE_HYPER_BAR
KMP_CACHE_PREFETCH(&other_threads[next_child_tid]->th.th_bar[bt].bb.b_go);
#endif /* KMP_CACHE_MANAGE */
#if KMP_BARRIER_ICV_PUSH
if (propagate_icvs) // push my fixed ICVs to my child
copy_icvs(&child_bar->th_fixed_icvs, &thr_bar->th_fixed_icvs);
#endif // KMP_BARRIER_ICV_PUSH
KA_TRACE(20, ("__kmp_hyper_barrier_release: T#%d(%d:%d) releasing T#%d(%d:%u)"
"go(%p): %u => %u\n", gtid, team->t.t_id, tid,
__kmp_gtid_from_tid(child_tid, team), team->t.t_id,
child_tid, &child_bar->b_go, child_bar->b_go,
child_bar->b_go + KMP_BARRIER_STATE_BUMP));
// Release child from barrier
kmp_flag_64 flag(&child_bar->b_go, child_thr);
flag.release();
}
}
}
#if KMP_BARRIER_ICV_PUSH
if (propagate_icvs && !KMP_MASTER_TID(tid)) { // copy ICVs locally to final dest
__kmp_init_implicit_task(team->t.t_ident, team->t.t_threads[tid], team, tid, FALSE);
copy_icvs(&team->t.t_implicit_task_taskdata[tid].td_icvs, &thr_bar->th_fixed_icvs);
}
#endif
KA_TRACE(20, ("__kmp_hyper_barrier_release: T#%d(%d:%d) exit for barrier type %d\n",
gtid, team->t.t_id, tid, bt));
}
// Hierarchical Barrier
// Initialize thread barrier data
/* Initializes/re-initializes the hierarchical barrier data stored on a thread. Performs the
minimum amount of initialization required based on how the team has changed. Returns true if
leaf children will require both on-core and traditional wake-up mechanisms. For example, if the
team size increases, threads already in the team will respond to on-core wakeup on their parent
thread, but threads newly added to the team will only be listening on the their local b_go. */
static bool
__kmp_init_hierarchical_barrier_thread(enum barrier_type bt, kmp_bstate_t *thr_bar, kmp_uint32 nproc,
int gtid, int tid, kmp_team_t *team)
{
// Checks to determine if (re-)initialization is needed
bool uninitialized = thr_bar->team == NULL;
bool team_changed = team != thr_bar->team;
bool team_sz_changed = nproc != thr_bar->nproc;
bool tid_changed = tid != thr_bar->old_tid;
bool retval = false;
if (uninitialized || team_sz_changed) {
__kmp_get_hierarchy(nproc, thr_bar);
}
if (uninitialized || team_sz_changed || tid_changed) {
thr_bar->my_level = thr_bar->depth-1; // default for master
thr_bar->parent_tid = -1; // default for master
if (!KMP_MASTER_TID(tid)) { // if not master, find parent thread in hierarchy
kmp_uint32 d=0;
while (d<thr_bar->depth) { // find parent based on level of thread in hierarchy, and note level
kmp_uint32 rem;
if (d == thr_bar->depth-2) { // reached level right below the master
thr_bar->parent_tid = 0;
thr_bar->my_level = d;
break;
}
else if ((rem = tid%thr_bar->skip_per_level[d+1]) != 0) { // TODO: can we make this op faster?
// thread is not a subtree root at next level, so this is max
thr_bar->parent_tid = tid - rem;
thr_bar->my_level = d;
break;
}
++d;
}
}
thr_bar->offset = 7-(tid-thr_bar->parent_tid-1);
thr_bar->old_tid = tid;
thr_bar->wait_flag = KMP_BARRIER_NOT_WAITING;
thr_bar->team = team;
thr_bar->parent_bar = &team->t.t_threads[thr_bar->parent_tid]->th.th_bar[bt].bb;
}
if (uninitialized || team_changed || tid_changed) {
thr_bar->team = team;
thr_bar->parent_bar = &team->t.t_threads[thr_bar->parent_tid]->th.th_bar[bt].bb;
retval = true;
}
if (uninitialized || team_sz_changed || tid_changed) {
thr_bar->nproc = nproc;
thr_bar->leaf_kids = thr_bar->base_leaf_kids;
if (thr_bar->my_level == 0) thr_bar->leaf_kids=0;
if (thr_bar->leaf_kids && (kmp_uint32)tid+thr_bar->leaf_kids+1 > nproc)
thr_bar->leaf_kids = nproc - tid - 1;
thr_bar->leaf_state = 0;
for (int i=0; i<thr_bar->leaf_kids; ++i) ((char *)&(thr_bar->leaf_state))[7-i] = 1;
}
return retval;
}
static void
__kmp_hierarchical_barrier_gather(enum barrier_type bt, kmp_info_t *this_thr,
int gtid, int tid, void (*reduce) (void *, void *)
USE_ITT_BUILD_ARG(void * itt_sync_obj) )
{
KMP_TIME_DEVELOPER_PARTITIONED_BLOCK(KMP_hier_gather);
register kmp_team_t *team = this_thr->th.th_team;
register kmp_bstate_t *thr_bar = & this_thr->th.th_bar[bt].bb;
register kmp_uint32 nproc = this_thr->th.th_team_nproc;
register kmp_info_t **other_threads = team->t.t_threads;
register kmp_uint64 new_state;
int level = team->t.t_level;
#if OMP_40_ENABLED
if (other_threads[0]->th.th_teams_microtask) // are we inside the teams construct?
if (this_thr->th.th_teams_size.nteams > 1)
++level; // level was not increased in teams construct for team_of_masters
#endif
if (level == 1) thr_bar->use_oncore_barrier = 1;
else thr_bar->use_oncore_barrier = 0; // Do not use oncore barrier when nested
KA_TRACE(20, ("__kmp_hierarchical_barrier_gather: T#%d(%d:%d) enter for barrier type %d\n",
gtid, team->t.t_id, tid, bt));
KMP_DEBUG_ASSERT(this_thr == other_threads[this_thr->th.th_info.ds.ds_tid]);
#if USE_ITT_BUILD && USE_ITT_NOTIFY
// Barrier imbalance - save arrive time to the thread
if(__kmp_forkjoin_frames_mode == 3 || __kmp_forkjoin_frames_mode == 2) {
this_thr->th.th_bar_arrive_time = __itt_get_timestamp();
}
#endif
(void)__kmp_init_hierarchical_barrier_thread(bt, thr_bar, nproc, gtid, tid, team);
if (thr_bar->my_level) { // not a leaf (my_level==0 means leaf)
register kmp_int32 child_tid;
new_state = (kmp_uint64)team->t.t_bar[bt].b_arrived + KMP_BARRIER_STATE_BUMP;
if (__kmp_dflt_blocktime == KMP_MAX_BLOCKTIME && thr_bar->use_oncore_barrier) {
if (thr_bar->leaf_kids) { // First, wait for leaf children to check-in on my b_arrived flag
kmp_uint64 leaf_state = KMP_MASTER_TID(tid) ? thr_bar->b_arrived | thr_bar->leaf_state : team->t.t_bar[bt].b_arrived | thr_bar->leaf_state;
KA_TRACE(20, ("__kmp_hierarchical_barrier_gather: T#%d(%d:%d) waiting for leaf kids\n",
gtid, team->t.t_id, tid));
kmp_flag_64 flag(&thr_bar->b_arrived, leaf_state);
flag.wait(this_thr, FALSE
USE_ITT_BUILD_ARG(itt_sync_obj) );
if (reduce) {
ANNOTATE_REDUCE_AFTER(reduce);
for (child_tid=tid+1; child_tid<=tid+thr_bar->leaf_kids; ++child_tid) {
KA_TRACE(100, ("__kmp_hierarchical_barrier_gather: T#%d(%d:%d) += T#%d(%d:%d)\n",
gtid, team->t.t_id, tid, __kmp_gtid_from_tid(child_tid, team),
team->t.t_id, child_tid));
(*reduce)(this_thr->th.th_local.reduce_data, other_threads[child_tid]->th.th_local.reduce_data);
}
ANNOTATE_REDUCE_BEFORE(reduce);
ANNOTATE_REDUCE_BEFORE(&team->t.t_bar);
}
(void) KMP_TEST_THEN_AND64((volatile kmp_int64 *)&thr_bar->b_arrived, ~(thr_bar->leaf_state)); // clear leaf_state bits
}
// Next, wait for higher level children on each child's b_arrived flag
for (kmp_uint32 d=1; d<thr_bar->my_level; ++d) { // gather lowest level threads first, but skip 0
kmp_uint32 last = tid+thr_bar->skip_per_level[d+1], skip = thr_bar->skip_per_level[d];
if (last > nproc) last = nproc;
for (child_tid=tid+skip; child_tid<(int)last; child_tid+=skip) {
register kmp_info_t *child_thr = other_threads[child_tid];
register kmp_bstate_t *child_bar = &child_thr->th.th_bar[bt].bb;
KA_TRACE(20, ("__kmp_hierarchical_barrier_gather: T#%d(%d:%d) wait T#%d(%d:%d) "
"arrived(%p) == %llu\n",
gtid, team->t.t_id, tid, __kmp_gtid_from_tid(child_tid, team),
team->t.t_id, child_tid, &child_bar->b_arrived, new_state));
kmp_flag_64 flag(&child_bar->b_arrived, new_state);
flag.wait(this_thr, FALSE
USE_ITT_BUILD_ARG(itt_sync_obj) );
if (reduce) {
KA_TRACE(100, ("__kmp_hierarchical_barrier_gather: T#%d(%d:%d) += T#%d(%d:%d)\n",
gtid, team->t.t_id, tid, __kmp_gtid_from_tid(child_tid, team),
team->t.t_id, child_tid));
ANNOTATE_REDUCE_AFTER(reduce);
(*reduce)(this_thr->th.th_local.reduce_data, child_thr->th.th_local.reduce_data);
ANNOTATE_REDUCE_BEFORE(reduce);
ANNOTATE_REDUCE_BEFORE(&team->t.t_bar);
}
}
}
}
else { // Blocktime is not infinite
for (kmp_uint32 d=0; d<thr_bar->my_level; ++d) { // Gather lowest level threads first
kmp_uint32 last = tid+thr_bar->skip_per_level[d+1], skip = thr_bar->skip_per_level[d];
if (last > nproc) last = nproc;
for (child_tid=tid+skip; child_tid<(int)last; child_tid+=skip) {
register kmp_info_t *child_thr = other_threads[child_tid];
register kmp_bstate_t *child_bar = &child_thr->th.th_bar[bt].bb;
KA_TRACE(20, ("__kmp_hierarchical_barrier_gather: T#%d(%d:%d) wait T#%d(%d:%d) "
"arrived(%p) == %llu\n",
gtid, team->t.t_id, tid, __kmp_gtid_from_tid(child_tid, team),
team->t.t_id, child_tid, &child_bar->b_arrived, new_state));
kmp_flag_64 flag(&child_bar->b_arrived, new_state);
flag.wait(this_thr, FALSE
USE_ITT_BUILD_ARG(itt_sync_obj) );
if (reduce) {
KA_TRACE(100, ("__kmp_hierarchical_barrier_gather: T#%d(%d:%d) += T#%d(%d:%d)\n",
gtid, team->t.t_id, tid, __kmp_gtid_from_tid(child_tid, team),
team->t.t_id, child_tid));
ANNOTATE_REDUCE_AFTER(reduce);
(*reduce)(this_thr->th.th_local.reduce_data, child_thr->th.th_local.reduce_data);
ANNOTATE_REDUCE_BEFORE(reduce);
ANNOTATE_REDUCE_BEFORE(&team->t.t_bar);
}
}
}
}
}
// All subordinates are gathered; now release parent if not master thread
if (!KMP_MASTER_TID(tid)) { // worker threads release parent in hierarchy
KA_TRACE(20, ("__kmp_hierarchical_barrier_gather: T#%d(%d:%d) releasing T#%d(%d:%d) "
"arrived(%p): %llu => %llu\n", gtid, team->t.t_id, tid,
__kmp_gtid_from_tid(thr_bar->parent_tid, team), team->t.t_id, thr_bar->parent_tid,
&thr_bar->b_arrived, thr_bar->b_arrived, thr_bar->b_arrived+KMP_BARRIER_STATE_BUMP));
/* Mark arrival to parent: After performing this write, a worker thread may not assume that
the team is valid any more - it could be deallocated by the master thread at any time. */
if (thr_bar->my_level || __kmp_dflt_blocktime != KMP_MAX_BLOCKTIME
|| !thr_bar->use_oncore_barrier) { // Parent is waiting on my b_arrived flag; release it
kmp_flag_64 flag(&thr_bar->b_arrived, other_threads[thr_bar->parent_tid]);
flag.release();
}
else { // Leaf does special release on the "offset" bits of parent's b_arrived flag
thr_bar->b_arrived = team->t.t_bar[bt].b_arrived + KMP_BARRIER_STATE_BUMP;
kmp_flag_oncore flag(&thr_bar->parent_bar->b_arrived, thr_bar->offset);
flag.set_waiter(other_threads[thr_bar->parent_tid]);
flag.release();
}
} else { // Master thread needs to update the team's b_arrived value
team->t.t_bar[bt].b_arrived = new_state;
KA_TRACE(20, ("__kmp_hierarchical_barrier_gather: T#%d(%d:%d) set team %d arrived(%p) = %llu\n",
gtid, team->t.t_id, tid, team->t.t_id, &team->t.t_bar[bt].b_arrived, team->t.t_bar[bt].b_arrived));
}
// Is the team access below unsafe or just technically invalid?
KA_TRACE(20, ("__kmp_hierarchical_barrier_gather: T#%d(%d:%d) exit for barrier type %d\n",
gtid, team->t.t_id, tid, bt));
}
static void
__kmp_hierarchical_barrier_release(enum barrier_type bt, kmp_info_t *this_thr, int gtid, int tid,
int propagate_icvs
USE_ITT_BUILD_ARG(void * itt_sync_obj) )
{
KMP_TIME_DEVELOPER_PARTITIONED_BLOCK(KMP_hier_release);
register kmp_team_t *team;
register kmp_bstate_t *thr_bar = &this_thr->th.th_bar[bt].bb;
register kmp_uint32 nproc;
bool team_change = false; // indicates on-core barrier shouldn't be used
if (KMP_MASTER_TID(tid)) {
team = __kmp_threads[gtid]->th.th_team;
KMP_DEBUG_ASSERT(team != NULL);
KA_TRACE(20, ("__kmp_hierarchical_barrier_release: T#%d(%d:%d) master entered barrier type %d\n",
gtid, team->t.t_id, tid, bt));
}
else { // Worker threads
// Wait for parent thread to release me
if (!thr_bar->use_oncore_barrier || __kmp_dflt_blocktime != KMP_MAX_BLOCKTIME
|| thr_bar->my_level != 0 || thr_bar->team == NULL) {
// Use traditional method of waiting on my own b_go flag
thr_bar->wait_flag = KMP_BARRIER_OWN_FLAG;
kmp_flag_64 flag(&thr_bar->b_go, KMP_BARRIER_STATE_BUMP);
flag.wait(this_thr, TRUE
USE_ITT_BUILD_ARG(itt_sync_obj) );
TCW_8(thr_bar->b_go, KMP_INIT_BARRIER_STATE); // Reset my b_go flag for next time
}
else { // Thread barrier data is initialized, this is a leaf, blocktime is infinite, not nested
// Wait on my "offset" bits on parent's b_go flag
thr_bar->wait_flag = KMP_BARRIER_PARENT_FLAG;
kmp_flag_oncore flag(&thr_bar->parent_bar->b_go, KMP_BARRIER_STATE_BUMP, thr_bar->offset,
bt, this_thr
USE_ITT_BUILD_ARG(itt_sync_obj) );
flag.wait(this_thr, TRUE);
if (thr_bar->wait_flag == KMP_BARRIER_SWITCHING) { // Thread was switched to own b_go
TCW_8(thr_bar->b_go, KMP_INIT_BARRIER_STATE); // Reset my b_go flag for next time
}
else { // Reset my bits on parent's b_go flag
((char*)&(thr_bar->parent_bar->b_go))[thr_bar->offset] = 0;
}
}
thr_bar->wait_flag = KMP_BARRIER_NOT_WAITING;
// Early exit for reaping threads releasing forkjoin barrier
if (bt == bs_forkjoin_barrier && TCR_4(__kmp_global.g.g_done))
return;
// The worker thread may now assume that the team is valid.
team = __kmp_threads[gtid]->th.th_team;
KMP_DEBUG_ASSERT(team != NULL);
tid = __kmp_tid_from_gtid(gtid);
KA_TRACE(20, ("__kmp_hierarchical_barrier_release: T#%d(%d:%d) set go(%p) = %u\n",
gtid, team->t.t_id, tid, &thr_bar->b_go, KMP_INIT_BARRIER_STATE));
KMP_MB(); // Flush all pending memory write invalidates.
}
nproc = this_thr->th.th_team_nproc;
int level = team->t.t_level;
#if OMP_40_ENABLED
if (team->t.t_threads[0]->th.th_teams_microtask ) { // are we inside the teams construct?
if (team->t.t_pkfn != (microtask_t)__kmp_teams_master && this_thr->th.th_teams_level == level)
++level; // level was not increased in teams construct for team_of_workers
if( this_thr->th.th_teams_size.nteams > 1 )
++level; // level was not increased in teams construct for team_of_masters
}
#endif
if (level == 1) thr_bar->use_oncore_barrier = 1;
else thr_bar->use_oncore_barrier = 0; // Do not use oncore barrier when nested
// If the team size has increased, we still communicate with old leaves via oncore barrier.
unsigned short int old_leaf_kids = thr_bar->leaf_kids;
kmp_uint64 old_leaf_state = thr_bar->leaf_state;
team_change = __kmp_init_hierarchical_barrier_thread(bt, thr_bar, nproc, gtid, tid, team);
// But if the entire team changes, we won't use oncore barrier at all
if (team_change) old_leaf_kids = 0;
#if KMP_BARRIER_ICV_PUSH
if (propagate_icvs) {
__kmp_init_implicit_task(team->t.t_ident, team->t.t_threads[tid], team, tid, FALSE);
if (KMP_MASTER_TID(tid)) { // master already has copy in final destination; copy
copy_icvs(&thr_bar->th_fixed_icvs, &team->t.t_implicit_task_taskdata[tid].td_icvs);
}
else if (__kmp_dflt_blocktime == KMP_MAX_BLOCKTIME && thr_bar->use_oncore_barrier) { // optimization for inf blocktime
if (!thr_bar->my_level) // I'm a leaf in the hierarchy (my_level==0)
// leaves (on-core children) pull parent's fixed ICVs directly to local ICV store
copy_icvs(&team->t.t_implicit_task_taskdata[tid].td_icvs,
&thr_bar->parent_bar->th_fixed_icvs);
// non-leaves will get ICVs piggybacked with b_go via NGO store
}
else { // blocktime is not infinite; pull ICVs from parent's fixed ICVs
if (thr_bar->my_level) // not a leaf; copy ICVs to my fixed ICVs child can access
copy_icvs(&thr_bar->th_fixed_icvs, &thr_bar->parent_bar->th_fixed_icvs);
else // leaves copy parent's fixed ICVs directly to local ICV store
copy_icvs(&team->t.t_implicit_task_taskdata[tid].td_icvs,
&thr_bar->parent_bar->th_fixed_icvs);
}
}
#endif // KMP_BARRIER_ICV_PUSH
// Now, release my children
if (thr_bar->my_level) { // not a leaf
register kmp_int32 child_tid;
kmp_uint32 last;
if (__kmp_dflt_blocktime == KMP_MAX_BLOCKTIME && thr_bar->use_oncore_barrier) {
if (KMP_MASTER_TID(tid)) { // do a flat release
// Set local b_go to bump children via NGO store of the cache line containing IVCs and b_go.
thr_bar->b_go = KMP_BARRIER_STATE_BUMP;
// Use ngo stores if available; b_go piggybacks in the last 8 bytes of the cache line
ngo_load(&thr_bar->th_fixed_icvs);
// This loops over all the threads skipping only the leaf nodes in the hierarchy
for (child_tid=thr_bar->skip_per_level[1]; child_tid<(int)nproc; child_tid+=thr_bar->skip_per_level[1]) {
register kmp_bstate_t *child_bar = &team->t.t_threads[child_tid]->th.th_bar[bt].bb;
KA_TRACE(20, ("__kmp_hierarchical_barrier_release: T#%d(%d:%d) releasing T#%d(%d:%d)"
" go(%p): %u => %u\n",
gtid, team->t.t_id, tid, __kmp_gtid_from_tid(child_tid, team),
team->t.t_id, child_tid, &child_bar->b_go, child_bar->b_go,
child_bar->b_go + KMP_BARRIER_STATE_BUMP));
// Use ngo store (if available) to both store ICVs and release child via child's b_go
ngo_store_go(&child_bar->th_fixed_icvs, &thr_bar->th_fixed_icvs);
}