[dpdk-dev] [PATCH] eal: move interrupt init after device init

[David Marchand <david.marchand@6wind.com>]

For virtio-net pmd, the interrupt management thread must be created after
this driver has initialised so that iopl() has been properly called and
its effects are inherited by all eal children threads.

Before this change, changing link status on a virtio-net device would
trigger a segfault in the interrupt thread :

$ mkdir -p /mnt/huge
$ echo 256 > /proc/sys/vm/nr_hugepages
$ mount -t hugetlbfs none /mnt/huge
$ lspci |grep Ethernet
00:03.0 Ethernet controller: Red Hat, Inc Virtio network device
$ modprobe uio
$ insmod ./x86_64-native-linuxapp-gcc/kmod/igb_uio.ko
$ echo 0000:00:03.0 > /sys/bus/pci/devices/0000\:00\:03.0/driver/unbind
$ echo 1af4 1000 > /sys/bus/pci/drivers/igb_uio/new_id
$ ./x86_64-native-linuxapp-gcc/app/testpmd -c 0x6 -n 3 -w 0000:00:03.0 -- -i --txqflags=0xf01 --total-num-mbufs 2048
[snip]
EAL: PCI device 0000:00:03.0 on NUMA socket -1
EAL:   probe driver: 1af4:1000 rte_virtio_pmd
Interactive-mode selected
Configuring Port 0 (socket 0)
Port 0: DE:AD:DE:01:02:03
Checking link statuses...
Port 0 Link Up - speed 10000 Mbps - full-duplex
Done
testpmd>

Then, from qemu monitor:
(qemu) set_link virtio-net-pci.0 off

testpmd> Segmentation fault

Fixes: "eal: set iopl only when needed" (565b85d)
Reported-by: Stephen Hemminger <shemming@brocade.com>
Suggested-by: Thomas Monjalon <thomas.monjalon@6wind.com>
Signed-off-by: David Marchand <david.marchand@6wind.com>
---
 lib/librte_eal/linuxapp/eal/eal.c |    6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/lib/librte_eal/linuxapp/eal/eal.c b/lib/librte_eal/linuxapp/eal/eal.c
index 33e1067..e0ad1d7 100644
--- a/lib/librte_eal/linuxapp/eal/eal.c
+++ b/lib/librte_eal/linuxapp/eal/eal.c
@@ -817,9 +817,6 @@ rte_eal_init(int argc, char **argv)
 	if (rte_eal_alarm_init() < 0)
 		rte_panic("Cannot init interrupt-handling thread\n");
 
-	if (rte_eal_intr_init() < 0)
-		rte_panic("Cannot init interrupt-handling thread\n");
-
 	if (rte_eal_timer_init() < 0)
 		rte_panic("Cannot init HPET or TSC timers\n");
 
@@ -845,6 +842,9 @@ rte_eal_init(int argc, char **argv)
 	if (rte_eal_dev_init() < 0)
 		rte_panic("Cannot init pmd devices\n");
 
+	if (rte_eal_intr_init() < 0)
+		rte_panic("Cannot init interrupt-handling thread\n");
+
 	RTE_LCORE_FOREACH_SLAVE(i) {
 
 		/*
-- 
1.7.10.4