[dpdk-dev] [PATCH v6 04/10] eal: introduce thread uninit helper

[David Marchand <david.marchand@redhat.com>]

This is a preparation step for dynamically unregistering threads.

Since we explicitly allocate a per thread trace buffer in
__rte_thread_init, add an internal helper to free this buffer.

Signed-off-by: David Marchand <david.marchand@redhat.com>
---
Changes since v5:
- fixed windows build,

Changes since v4:
- renamed rte_thread_uninit and moved to eal_private.h,
- hid freeing helper,

Changes since v2:
- added missing stub for windows tracing support,
- moved free symbol to exported (experimental) ABI as a counterpart of
  the alloc symbol we already had,

Changes since v1:
- rebased on master, removed Windows workaround wrt traces support,

---
 lib/librte_eal/common/eal_common_thread.c |  9 +++++
 lib/librte_eal/common/eal_common_trace.c  | 49 +++++++++++++++++++----
 lib/librte_eal/common/eal_private.h       |  5 +++
 lib/librte_eal/common/eal_trace.h         |  1 +
 lib/librte_eal/windows/eal.c              |  7 +++-
 5 files changed, 63 insertions(+), 8 deletions(-)

diff --git a/lib/librte_eal/common/eal_common_thread.c b/lib/librte_eal/common/eal_common_thread.c
index fb06f8f802..6d1c87b1c2 100644
--- a/lib/librte_eal/common/eal_common_thread.c
+++ b/lib/librte_eal/common/eal_common_thread.c
@@ -20,6 +20,7 @@
 #include "eal_internal_cfg.h"
 #include "eal_private.h"
 #include "eal_thread.h"
+#include "eal_trace.h"
 
 RTE_DEFINE_PER_LCORE(unsigned int, _lcore_id) = LCORE_ID_ANY;
 RTE_DEFINE_PER_LCORE(int, _thread_id) = -1;
@@ -161,6 +162,14 @@ __rte_thread_init(unsigned int lcore_id, rte_cpuset_t *cpuset)
 	__rte_trace_mem_per_thread_alloc();
 }
 
+void
+__rte_thread_uninit(void)
+{
+	trace_mem_per_thread_free();
+
+	RTE_PER_LCORE(_lcore_id) = LCORE_ID_ANY;
+}
+
 struct rte_thread_ctrl_params {
 	void *(*start_routine)(void *);
 	void *arg;
diff --git a/lib/librte_eal/common/eal_common_trace.c b/lib/librte_eal/common/eal_common_trace.c
index 875553d7e5..b6da5537fe 100644
--- a/lib/librte_eal/common/eal_common_trace.c
+++ b/lib/librte_eal/common/eal_common_trace.c
@@ -101,7 +101,7 @@ eal_trace_fini(void)
 {
 	if (!rte_trace_is_enabled())
 		return;
-	trace_mem_per_thread_free();
+	trace_mem_free();
 	trace_metadata_destroy();
 	eal_trace_args_free();
 }
@@ -370,24 +370,59 @@ __rte_trace_mem_per_thread_alloc(void)
 	rte_spinlock_unlock(&trace->lock);
 }
 
+static void
+trace_mem_per_thread_free_unlocked(struct thread_mem_meta *meta)
+{
+	if (meta->area == TRACE_AREA_HUGEPAGE)
+		eal_free_no_trace(meta->mem);
+	else if (meta->area == TRACE_AREA_HEAP)
+		free(meta->mem);
+}
+
 void
 trace_mem_per_thread_free(void)
+{
+	struct trace *trace = trace_obj_get();
+	struct __rte_trace_header *header;
+	uint32_t count;
+
+	header = RTE_PER_LCORE(trace_mem);
+	if (header == NULL)
+		return;
+
+	rte_spinlock_lock(&trace->lock);
+	for (count = 0; count < trace->nb_trace_mem_list; count++) {
+		if (trace->lcore_meta[count].mem == header)
+			break;
+	}
+	if (count != trace->nb_trace_mem_list) {
+		struct thread_mem_meta *meta = &trace->lcore_meta[count];
+
+		trace_mem_per_thread_free_unlocked(meta);
+		if (count != trace->nb_trace_mem_list - 1) {
+			memmove(meta, meta + 1,
+				sizeof(*meta) *
+				 (trace->nb_trace_mem_list - count - 1));
+		}
+		trace->nb_trace_mem_list--;
+	}
+	rte_spinlock_unlock(&trace->lock);
+}
+
+void
+trace_mem_free(void)
 {
 	struct trace *trace = trace_obj_get();
 	uint32_t count;
-	void *mem;
 
 	if (!rte_trace_is_enabled())
 		return;
 
 	rte_spinlock_lock(&trace->lock);
 	for (count = 0; count < trace->nb_trace_mem_list; count++) {
-		mem = trace->lcore_meta[count].mem;
-		if (trace->lcore_meta[count].area == TRACE_AREA_HUGEPAGE)
-			eal_free_no_trace(mem);
-		else if (trace->lcore_meta[count].area == TRACE_AREA_HEAP)
-			free(mem);
+		trace_mem_per_thread_free_unlocked(&trace->lcore_meta[count]);
 	}
+	trace->nb_trace_mem_list = 0;
 	rte_spinlock_unlock(&trace->lock);
 }
 
diff --git a/lib/librte_eal/common/eal_private.h b/lib/librte_eal/common/eal_private.h
index 5d8b53882d..a77ac7a963 100644
--- a/lib/librte_eal/common/eal_private.h
+++ b/lib/librte_eal/common/eal_private.h
@@ -709,4 +709,9 @@ eal_get_application_usage_hook(void);
  */
 void __rte_thread_init(unsigned int lcore_id, rte_cpuset_t *cpuset);
 
+/**
+ * Uninitialize per-lcore info for current thread.
+ */
+void __rte_thread_uninit(void);
+
 #endif /* _EAL_PRIVATE_H_ */
diff --git a/lib/librte_eal/common/eal_trace.h b/lib/librte_eal/common/eal_trace.h
index 8f60616156..92c5951c3a 100644
--- a/lib/librte_eal/common/eal_trace.h
+++ b/lib/librte_eal/common/eal_trace.h
@@ -106,6 +106,7 @@ int trace_metadata_create(void);
 void trace_metadata_destroy(void);
 int trace_mkdir(void);
 int trace_epoch_time_save(void);
+void trace_mem_free(void);
 void trace_mem_per_thread_free(void);
 
 /* EAL interface */
diff --git a/lib/librte_eal/windows/eal.c b/lib/librte_eal/windows/eal.c
index 9f5d019e64..addac62ae5 100644
--- a/lib/librte_eal/windows/eal.c
+++ b/lib/librte_eal/windows/eal.c
@@ -17,10 +17,10 @@
 #include <eal_filesystem.h>
 #include <eal_options.h>
 #include <eal_private.h>
-#include <rte_trace_point.h>
 #include <rte_vfio.h>
 
 #include "eal_hugepages.h"
+#include "eal_trace.h"
 #include "eal_windows.h"
 
 #define MEMSIZE_IF_NO_HUGE_PAGE (64ULL * 1024ULL * 1024ULL)
@@ -215,6 +215,11 @@ __rte_trace_mem_per_thread_alloc(void)
 {
 }
 
+void
+trace_mem_per_thread_free(void)
+{
+}
+
 void
 __rte_trace_point_emit_field(size_t sz, const char *field,
 	const char *type)
-- 
2.23.0