From: Rahul Gupta <rahulg...@microsoft.com>
Initialization often requires rte_eal_init + rte_pktmbuf_pool_create
which can consume a total time of 500-600 ms:
a) For many devices FLR may take a significant chunk of time
(200-250 ms in our use-case), this FLR is triggered during device
probe in rte_eal_init().
b) rte_pktmbuf_pool_create() can consume upto 300-350 ms for
applications that require huge memory.
This cost is incurred on each restart (which happens in our use-case
during binary updates for servicing).
This patch provides an optimization using pthreads that appplications
can use and which can save 200-230ms.
In this patch, rte_eal_init() is refactored into two parts-
a) 1st part is dependent code ie- it’s a perquisite of the FLR and
mempool creation. So this code needs to be executed before any
pthreads. Its named as rte_eal_init_setup()
b) 2nd part of code is independent code ie- it can execute in parallel
to mempool creation in a pthread. Its named as rte_probe_and_ioctl().
Existing applications require no changes unless they wish to leverage
the optimization.
If the application wants to use pthread functionality, it should call-
a) rte_eal_init_setup() then create two or more pthreads-
b) in one pthread call- rte_probe_and_ioctl(),
c) second pthread call- rte_pktmbuf_pool_create()
d) (optional) Other pthreads for any other independent function.
Signed-off-by: Rahul Gupta <rahulg...@linux.microsoft.com>
---
lib/librte_eal/common/include/rte_eal.h | 2 ++
lib/librte_eal/linux/eal/eal.c | 18 ++++++++++++++++--
lib/librte_eal/rte_eal_version.map | 2 ++
3 files changed, 20 insertions(+), 2 deletions(-)
diff --git a/lib/librte_eal/common/include/rte_eal.h
b/lib/librte_eal/common/include/rte_eal.h
index 2f9ed29..90db16b 100644
--- a/lib/librte_eal/common/include/rte_eal.h
+++ b/lib/librte_eal/common/include/rte_eal.h
@@ -129,6 +129,8 @@ enum rte_proc_type_t {
* ENOEXEC indicates that a service core failed to launch successfully.
*/
int rte_eal_init(int argc, char **argv);
+int rte_eal_init_setup(int argc, char **argv);
+int rte_probe_and_ioctl(void);
/**
* Clean up the Environment Abstraction Layer (EAL)
diff --git a/lib/librte_eal/linux/eal/eal.c b/lib/librte_eal/linux/eal/eal.c
index 5cabba8..6f2a4d0 100644
--- a/lib/librte_eal/linux/eal/eal.c
+++ b/lib/librte_eal/linux/eal/eal.c
@@ -956,9 +956,8 @@ static void rte_eal_init_alert(const char *msg)
return n > 2;
}
-/* Launch threads, called at application init(). */
int
-rte_eal_init(int argc, char **argv)
+rte_eal_init_setup(int argc, char **argv)
{
int i, fctret, ret;
pthread_t thread_id;
@@ -1246,7 +1245,13 @@ static void rte_eal_init_alert(const char *msg)
*/
rte_eal_mp_remote_launch(sync_func, NULL, SKIP_MASTER);
rte_eal_mp_wait_lcore();
+ return fctret;
+}
+int
+rte_probe_and_ioctl(void)
+{
+ int ret = 0;
/* initialize services so vdevs register service during bus_probe. */
ret = rte_service_init();
if (ret) {
@@ -1296,7 +1301,16 @@ static void rte_eal_init_alert(const char *msg)
/* Call each registered callback, if enabled */
rte_option_init();
+ return 0; //return Success if control reaches here
+}
+/* Launch threads, called at application init(). */
+int
+rte_eal_init(int argc, char **argv)
+{
+ int fctret = rte_eal_init_setup(argc, argv);
+ if (fctret>=0)
+ fctret = rte_probe_and_ioctl();
return fctret;
}
diff --git a/lib/librte_eal/rte_eal_version.map
b/lib/librte_eal/rte_eal_version.map
index 6482539..9e6054f 100644
--- a/lib/librte_eal/rte_eal_version.map
+++ b/lib/librte_eal/rte_eal_version.map
@@ -53,6 +53,8 @@ DPDK_20.0 {
rte_eal_hotplug_remove;
rte_eal_hpet_init;
rte_eal_init;
+ rte_eal_init_setup;
+ rte_probe_and_ioctl;
rte_eal_iopl_init;
rte_eal_iova_mode;
rte_eal_lcore_role;
--
1.8.3.1
