So far, a worker thread has been using its thread_id to discover which
lcore has been assigned to it.
On the other hand, as noted by Tyler, the pthread API does not strictly
guarantee that a new thread won't start running eal_thread_loop before
pthread_create writes to &lcore_config[xx].thread_id.
Though all OS implementations supported in DPDK (recently) ensure this
property, it is more robust to have the main thread directly pass
the worker thread lcore.
Signed-off-by: David Marchand <david.march...@redhat.com>
---
Changes since v2:
- fixed Windows compilation,
---
lib/eal/common/eal_thread.h | 4 ++--
lib/eal/freebsd/eal.c | 2 +-
lib/eal/freebsd/eal_thread.c | 16 +++-------------
lib/eal/linux/eal.c | 2 +-
lib/eal/linux/eal_thread.c | 17 ++++-------------
lib/eal/windows/eal.c | 2 +-
lib/eal/windows/eal_thread.c | 23 +++++++----------------
lib/eal/windows/eal_windows.h | 4 +++-
8 files changed, 22 insertions(+), 48 deletions(-)
diff --git a/lib/eal/common/eal_thread.h b/lib/eal/common/eal_thread.h
index 4a49117be8..3c84efd553 100644
--- a/lib/eal/common/eal_thread.h
+++ b/lib/eal/common/eal_thread.h
@@ -8,10 +8,10 @@
#include <rte_lcore.h>
/**
- * basic loop of thread, called for each thread by eal_init().
+ * Basic loop of EAL thread, called for each worker thread by rte_eal_init().
*
* @param arg
- * opaque pointer
+ * The lcore_id (passed as an integer) of this worker thread.
*/
__rte_noreturn void *eal_thread_loop(void *arg);
diff --git a/lib/eal/freebsd/eal.c b/lib/eal/freebsd/eal.c
index 71993fe25b..e233e57184 100644
--- a/lib/eal/freebsd/eal.c
+++ b/lib/eal/freebsd/eal.c
@@ -813,7 +813,7 @@ rte_eal_init(int argc, char **argv)
/* create a thread for each lcore */
ret = pthread_create(&lcore_config[i].thread_id, NULL,
- eal_thread_loop, NULL);
+ eal_thread_loop, (void *)(uintptr_t)i);
if (ret != 0)
rte_panic("Cannot create thread\n");
diff --git a/lib/eal/freebsd/eal_thread.c b/lib/eal/freebsd/eal_thread.c
index 3b18030d73..9044d70ef7 100644
--- a/lib/eal/freebsd/eal_thread.c
+++ b/lib/eal/freebsd/eal_thread.c
@@ -76,25 +76,15 @@ rte_eal_remote_launch(int (*f)(void *), void *arg, unsigned
worker_id)
/* main loop of threads */
__rte_noreturn void *
-eal_thread_loop(__rte_unused void *arg)
+eal_thread_loop(void *arg)
{
+ unsigned int lcore_id = (uintptr_t)arg;
char c;
int n, ret;
unsigned lcore_id;
- pthread_t thread_id;
int m2w, w2m;
char cpuset[RTE_CPU_AFFINITY_STR_LEN];
- thread_id = pthread_self();
-
- /* retrieve our lcore_id from the configuration structure */
- RTE_LCORE_FOREACH_WORKER(lcore_id) {
- if (thread_id == lcore_config[lcore_id].thread_id)
- break;
- }
- if (lcore_id == RTE_MAX_LCORE)
- rte_panic("cannot retrieve lcore id\n");
-
m2w = lcore_config[lcore_id].pipe_main2worker[0];
w2m = lcore_config[lcore_id].pipe_worker2main[1];
@@ -102,7 +92,7 @@ eal_thread_loop(__rte_unused void *arg)
ret = eal_thread_dump_current_affinity(cpuset, sizeof(cpuset));
RTE_LOG(DEBUG, EAL, "lcore %u is ready (tid=%p;cpuset=[%s%s])\n",
- lcore_id, thread_id, cpuset, ret == 0 ? "" : "...");
+ lcore_id, pthread_self(), cpuset, ret == 0 ? "" : "...");
rte_eal_trace_thread_lcore_ready(lcore_id, cpuset);
diff --git a/lib/eal/linux/eal.c b/lib/eal/linux/eal.c
index 025e5cc10d..98c6838026 100644
--- a/lib/eal/linux/eal.c
+++ b/lib/eal/linux/eal.c
@@ -1147,7 +1147,7 @@ rte_eal_init(int argc, char **argv)
/* create a thread for each lcore */
ret = pthread_create(&lcore_config[i].thread_id, NULL,
- eal_thread_loop, NULL);
+ eal_thread_loop, (void *)(uintptr_t)i);
if (ret != 0)
rte_panic("Cannot create thread\n");
diff --git a/lib/eal/linux/eal_thread.c b/lib/eal/linux/eal_thread.c
index fa6cd7e2c4..26b0a7d48a 100644
--- a/lib/eal/linux/eal_thread.c
+++ b/lib/eal/linux/eal_thread.c
@@ -70,24 +70,14 @@ rte_eal_remote_launch(int (*f)(void *), void *arg, unsigned
int worker_id)
/* main loop of threads */
__rte_noreturn void *
-eal_thread_loop(__rte_unused void *arg)
+eal_thread_loop(void *arg)
{
+ unsigned int lcore_id = (uintptr_t)arg;
char c;
int n, ret;
- unsigned lcore_id;
- pthread_t thread_id;
int m2w, w2m;
char cpuset[RTE_CPU_AFFINITY_STR_LEN];
- thread_id = pthread_self();
-
- /* retrieve our lcore_id from the configuration structure */
- RTE_LCORE_FOREACH_WORKER(lcore_id) {
- if (thread_id == lcore_config[lcore_id].thread_id)
- break;
- }
- if (lcore_id == RTE_MAX_LCORE)
- rte_panic("cannot retrieve lcore id\n");
m2w = lcore_config[lcore_id].pipe_main2worker[0];
w2m = lcore_config[lcore_id].pipe_worker2main[1];
@@ -96,7 +86,8 @@ eal_thread_loop(__rte_unused void *arg)
ret = eal_thread_dump_current_affinity(cpuset, sizeof(cpuset));
RTE_LOG(DEBUG, EAL, "lcore %u is ready (tid=%zx;cpuset=[%s%s])\n",
- lcore_id, (uintptr_t)thread_id, cpuset, ret == 0 ? "" : "...");
+ lcore_id, (uintptr_t)pthread_self(), cpuset,
+ ret == 0 ? "" : "...");
rte_eal_trace_thread_lcore_ready(lcore_id, cpuset);
diff --git a/lib/eal/windows/eal.c b/lib/eal/windows/eal.c
index ca3c41aaa7..1874f9f6d7 100644
--- a/lib/eal/windows/eal.c
+++ b/lib/eal/windows/eal.c
@@ -420,7 +420,7 @@ rte_eal_init(int argc, char **argv)
lcore_config[i].state = WAIT;
/* create a thread for each lcore */
- if (eal_thread_create(&lcore_config[i].thread_id) != 0)
+ if (eal_thread_create(&lcore_config[i].thread_id, i) != 0)
rte_panic("Cannot create thread\n");
ret = pthread_setaffinity_np(lcore_config[i].thread_id,
sizeof(rte_cpuset_t), &lcore_config[i].cpuset);
diff --git a/lib/eal/windows/eal_thread.c b/lib/eal/windows/eal_thread.c
index ff84cb42af..95e96548de 100644
--- a/lib/eal/windows/eal_thread.c
+++ b/lib/eal/windows/eal_thread.c
@@ -63,32 +63,21 @@ rte_eal_remote_launch(lcore_function_t *f, void *arg,
unsigned int worker_id)
/* main loop of threads */
void *
-eal_thread_loop(void *arg __rte_unused)
+eal_thread_loop(void *arg)
{
+ unsigned int lcore_id = (uintptr_t)arg;
char c;
int n, ret;
- unsigned int lcore_id;
- pthread_t thread_id;
int m2w, w2m;
char cpuset[RTE_CPU_AFFINITY_STR_LEN];
- thread_id = pthread_self();
-
- /* retrieve our lcore_id from the configuration structure */
- RTE_LCORE_FOREACH_WORKER(lcore_id) {
- if (thread_id == lcore_config[lcore_id].thread_id)
- break;
- }
- if (lcore_id == RTE_MAX_LCORE)
- rte_panic("cannot retrieve lcore id\n");
-
m2w = lcore_config[lcore_id].pipe_main2worker[0];
w2m = lcore_config[lcore_id].pipe_worker2main[1];
__rte_thread_init(lcore_id, &lcore_config[lcore_id].cpuset);
RTE_LOG(DEBUG, EAL, "lcore %u is ready (tid=%zx;cpuset=[%s])\n",
- lcore_id, (uintptr_t)thread_id, cpuset);
+ lcore_id, (uintptr_t)pthread_self(), cpuset);
/* read on our pipe to get commands */
while (1) {
@@ -144,13 +133,15 @@ eal_thread_loop(void *arg __rte_unused)
/* function to create threads */
int
-eal_thread_create(pthread_t *thread)
+eal_thread_create(pthread_t *thread, unsigned int lcore_id)
{
HANDLE th;
th = CreateThread(NULL, 0,
(LPTHREAD_START_ROUTINE)(ULONG_PTR)eal_thread_loop,
- NULL, CREATE_SUSPENDED,
(LPDWORD)thread);
+ (LPVOID)(uintptr_t)lcore_id,
+ CREATE_SUSPENDED,
+ (LPDWORD)thread);
if (!th)
return -1;
diff --git a/lib/eal/windows/eal_windows.h b/lib/eal/windows/eal_windows.h
index 245aa60344..e4c46705c6 100644
--- a/lib/eal/windows/eal_windows.h
+++ b/lib/eal/windows/eal_windows.h
@@ -40,10 +40,12 @@ int eal_create_cpu_map(void);
*
* @param thread
* The location to store the thread id if successful.
+ * @param lcore_id
+ * The lcore_id of this worker thread.
* @return
* 0 for success, -1 if the thread is not created.
*/
-int eal_thread_create(pthread_t *thread);
+int eal_thread_create(pthread_t *thread, unsigned int lcore_id);
/**
* Get system NUMA node number for a socket ID.
--
2.23.0
