Re: [dpdk-dev] [PATCH 1/7] eal: use different constructor priorities for initcalls

[Shreyansh Jain]

On Wednesday 15 February 2017 03:32 PM, Jan Blunck wrote:

This introduces different initcall macros to allow for late registration of
the virtual device bus.

Signed-off-by: Jan Blunck <jblu...@infradead.org>
---
 lib/librte_eal/common/include/rte_bus.h   | 17 ++++++++++++++++-
 lib/librte_eal/common/include/rte_eal.h   | 12 ++++++++++--
 lib/librte_eal/common/include/rte_tailq.h |  2 +-
 3 files changed, 27 insertions(+), 4 deletions(-)

diff --git a/lib/librte_eal/common/include/rte_bus.h 
b/lib/librte_eal/common/include/rte_bus.h
index 7c36969..9f161f2 100644
--- a/lib/librte_eal/common/include/rte_bus.h
+++ b/lib/librte_eal/common/include/rte_bus.h
@@ -50,6 +50,7 @@ extern "C" {
 #include <stdio.h>
 #include <sys/queue.h>

+#include <rte_eal.h>
 #include <rte_log.h>
 #include <rte_dev.h>

@@ -145,7 +146,21 @@ void rte_bus_dump(FILE *f);
  * The constructor has higher priority than PMD constructors.
  */
 #define RTE_REGISTER_BUS(nm, bus) \
-static void __attribute__((constructor(101), used)) businitfn_ ##nm(void) \
+RTE_EAL_INIT(businitfn_ ##nm); \
+static void businitfn_ ##nm(void) \
+{\
+       (bus).name = RTE_STR(nm);\
+       rte_bus_register(&bus); \
+}
+
+/**
+ * Helper for late Bus registration.
+ * The constructor still has higher priority than PMD constructors but has
+ * lower priority than RTE_REGISTER_BUS.
+ */
+#define RTE_REGISTER_BUS_LATE(nm, bus) \
+RTE_POST_EAL_INIT(businitfn_ ##nm); \
+static void businitfn_ ##nm(void) \
 {\
        (bus).name = RTE_STR(nm);\
        rte_bus_register(&bus); \
diff --git a/lib/librte_eal/common/include/rte_eal.h 
b/lib/librte_eal/common/include/rte_eal.h
index 03fee50..3a6bd71 100644
--- a/lib/librte_eal/common/include/rte_eal.h
+++ b/lib/librte_eal/common/include/rte_eal.h
@@ -258,8 +258,16 @@ static inline int rte_gettid(void)
        return RTE_PER_LCORE(_thread_id);
 }

-#define RTE_INIT(func) \
-static void __attribute__((constructor, used)) func(void)
+#define RTE_EAL_INIT(func) \
+static void __attribute__((constructor(101), used)) func(void)
+
+#define RTE_POST_EAL_INIT(func) \
+static void __attribute__((constructor(102), used)) func(void)
+
+#define RTE_DEV_INIT(func) \
+static void __attribute__((constructor(103), used)) func(void)

Shouldn't we simply allow this priority to be default to allow for some
priority space between buses and default init?

+
+#define RTE_INIT(func) RTE_DEV_INIT(func)

 #ifdef __cplusplus
 }
diff --git a/lib/librte_eal/common/include/rte_tailq.h 
b/lib/librte_eal/common/include/rte_tailq.h
index 3aae098..07ceec1 100644
--- a/lib/librte_eal/common/include/rte_tailq.h
+++ b/lib/librte_eal/common/include/rte_tailq.h
@@ -148,7 +148,7 @@ struct rte_tailq_head *rte_eal_tailq_lookup(const char 
*name);
 int rte_eal_tailq_register(struct rte_tailq_elem *t);

 #define EAL_REGISTER_TAILQ(t) \
-RTE_INIT(tailqinitfn_ ##t); \
+RTE_EAL_INIT(tailqinitfn_ ##t); \
 static void tailqinitfn_ ##t(void) \
 { \
        if (rte_eal_tailq_register(&t) < 0) \