[PATCH v3 5/5] eal/x86: defer power intrinsics variable allocation

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

The lcore variable in this code unit is only used through
rte_power_monitor*() public symbols.

Defer the unconditional lcore variable allocation in those symbols.

Fixes: 18b5049ab4fe ("eal/x86: keep power intrinsics state in lcore variable")
Cc: stable@dpdk.org

Signed-off-by: David Marchand <david.marchand@redhat.com>
Acked-by: Anatoly Burakov <anatoly.burakov@intel.com>
Acked-by: Frode Nordahl <frode.nordahl@canonical.com>
---
Changes since v1:
- added an initialiser helper,

---
 lib/eal/x86/rte_power_intrinsics.c | 15 +++++++++++++--
 1 file changed, 13 insertions(+), 2 deletions(-)

diff --git a/lib/eal/x86/rte_power_intrinsics.c b/lib/eal/x86/rte_power_intrinsics.c
index e4cb913590..f7d558153e 100644
--- a/lib/eal/x86/rte_power_intrinsics.c
+++ b/lib/eal/x86/rte_power_intrinsics.c
@@ -22,7 +22,13 @@ struct power_wait_status {
 
 RTE_LCORE_VAR_HANDLE(struct power_wait_status, wait_status);
 
-RTE_LCORE_VAR_INIT(wait_status);
+static void
+init_wait_status(void)
+{
+	if (wait_status != NULL)
+		return;
+	RTE_LCORE_VAR_ALLOC(wait_status);
+}
 
 /*
  * This function uses UMONITOR/UMWAIT instructions and will enter C0.2 state.
@@ -177,6 +183,7 @@ rte_power_monitor(const struct rte_power_monitor_cond *pmc,
 	if (pmc->fn == NULL)
 		return -EINVAL;
 
+	init_wait_status();
 	s = RTE_LCORE_VAR_LCORE(lcore_id, wait_status);
 
 	/* update sleep address */
@@ -269,6 +276,7 @@ rte_power_monitor_wakeup(const unsigned int lcore_id)
 	if (lcore_id >= RTE_MAX_LCORE)
 		return -EINVAL;
 
+	init_wait_status();
 	s = RTE_LCORE_VAR_LCORE(lcore_id, wait_status);
 
 	/*
@@ -308,7 +316,7 @@ int
 rte_power_monitor_multi(const struct rte_power_monitor_cond pmc[],
 		const uint32_t num, const uint64_t tsc_timestamp)
 {
-	struct power_wait_status *s = RTE_LCORE_VAR(wait_status);
+	struct power_wait_status *s;
 	uint32_t i, rc;
 
 	/* check if supported */
@@ -318,6 +326,9 @@ rte_power_monitor_multi(const struct rte_power_monitor_cond pmc[],
 	if (pmc == NULL || num == 0)
 		return -EINVAL;
 
+	init_wait_status();
+	s = RTE_LCORE_VAR(wait_status);
+
 	/* we are already inside transaction region, return */
 	if (rte_xtest() != 0)
 		return 0;
-- 
2.48.1