* [dpdk-dev] [PATCH v6] net/tap: fix missing _SC_IOV_MAX
@ 2019-03-18 16:55 olegpoly123
2019-03-18 16:55 ` olegpoly123
2019-03-18 17:56 ` Stephen Hemminger
0 siblings, 2 replies; 4+ messages in thread
From: olegpoly123 @ 2019-03-18 16:55 UTC (permalink / raw)
To: keith.wiles, thomas; +Cc: dev, olegpoly123, stable
If the value _SC_IOV_MAX is missing, sysconf returns -1.
In this case, iov_max is set to a default value of 1024.
Fixes: ec12df9504fe ("net/tap: fix support for large Rx queues")
Cc: stable@dpdk.org
Signed-off-by: Oleg Polyakov <olegp123@walla.co.il>
Acked-by: Keith Wiles <keith.wiles@intel.com>
---
drivers/net/tap/rte_eth_tap.c | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/drivers/net/tap/rte_eth_tap.c b/drivers/net/tap/rte_eth_tap.c
index 6f5109fca..8f7c552b3 100644
--- a/drivers/net/tap/rte_eth_tap.c
+++ b/drivers/net/tap/rte_eth_tap.c
@@ -68,6 +68,8 @@
/* IPC key for queue fds sync */
#define TAP_MP_KEY "tap_mp_sync_queues"
+#define TAP_IOV_DEFAULT_MAX 1024
+
static int tap_devices_count;
static struct rte_vdev_driver pmd_tap_drv;
static struct rte_vdev_driver pmd_tun_drv;
@@ -1326,6 +1328,13 @@ tap_rx_queue_setup(struct rte_eth_dev *dev,
struct rx_queue *rxq = &internals->rxq[rx_queue_id];
struct rte_mbuf **tmp = &rxq->pool;
long iov_max = sysconf(_SC_IOV_MAX);
+
+ if (iov_max <= 0) {
+ TAP_LOG(WARNING,
+ "_SC_IOV_MAX is not defined. Using %d as default\n",
+ TAP_IOV_DEFAULT_MAX);
+ iov_max = TAP_IOV_DEFAULT_MAX;
+ }
uint16_t nb_desc = RTE_MIN(nb_rx_desc, iov_max - 1);
struct iovec (*iovecs)[nb_desc + 1];
int data_off = RTE_PKTMBUF_HEADROOM;
--
2.14.1
^ permalink raw reply [flat|nested] 4+ messages in thread* [dpdk-dev] [PATCH v6] net/tap: fix missing _SC_IOV_MAX
2019-03-18 16:55 [dpdk-dev] [PATCH v6] net/tap: fix missing _SC_IOV_MAX olegpoly123
@ 2019-03-18 16:55 ` olegpoly123
2019-03-18 17:56 ` Stephen Hemminger
1 sibling, 0 replies; 4+ messages in thread
From: olegpoly123 @ 2019-03-18 16:55 UTC (permalink / raw)
To: keith.wiles, thomas; +Cc: dev, olegpoly123, stable
If the value _SC_IOV_MAX is missing, sysconf returns -1.
In this case, iov_max is set to a default value of 1024.
Fixes: ec12df9504fe ("net/tap: fix support for large Rx queues")
Cc: stable@dpdk.org
Signed-off-by: Oleg Polyakov <olegp123@walla.co.il>
Acked-by: Keith Wiles <keith.wiles@intel.com>
---
drivers/net/tap/rte_eth_tap.c | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/drivers/net/tap/rte_eth_tap.c b/drivers/net/tap/rte_eth_tap.c
index 6f5109fca..8f7c552b3 100644
--- a/drivers/net/tap/rte_eth_tap.c
+++ b/drivers/net/tap/rte_eth_tap.c
@@ -68,6 +68,8 @@
/* IPC key for queue fds sync */
#define TAP_MP_KEY "tap_mp_sync_queues"
+#define TAP_IOV_DEFAULT_MAX 1024
+
static int tap_devices_count;
static struct rte_vdev_driver pmd_tap_drv;
static struct rte_vdev_driver pmd_tun_drv;
@@ -1326,6 +1328,13 @@ tap_rx_queue_setup(struct rte_eth_dev *dev,
struct rx_queue *rxq = &internals->rxq[rx_queue_id];
struct rte_mbuf **tmp = &rxq->pool;
long iov_max = sysconf(_SC_IOV_MAX);
+
+ if (iov_max <= 0) {
+ TAP_LOG(WARNING,
+ "_SC_IOV_MAX is not defined. Using %d as default\n",
+ TAP_IOV_DEFAULT_MAX);
+ iov_max = TAP_IOV_DEFAULT_MAX;
+ }
uint16_t nb_desc = RTE_MIN(nb_rx_desc, iov_max - 1);
struct iovec (*iovecs)[nb_desc + 1];
int data_off = RTE_PKTMBUF_HEADROOM;
--
2.14.1
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [dpdk-dev] [PATCH v6] net/tap: fix missing _SC_IOV_MAX
2019-03-18 16:55 [dpdk-dev] [PATCH v6] net/tap: fix missing _SC_IOV_MAX olegpoly123
2019-03-18 16:55 ` olegpoly123
@ 2019-03-18 17:56 ` Stephen Hemminger
2019-03-18 17:56 ` Stephen Hemminger
1 sibling, 1 reply; 4+ messages in thread
From: Stephen Hemminger @ 2019-03-18 17:56 UTC (permalink / raw)
To: olegpoly123; +Cc: keith.wiles, thomas, dev, stable
On Mon, 18 Mar 2019 12:55:23 -0400
olegpoly123 <olegp123@walla.co.il> wrote:
> long iov_max = sysconf(_SC_IOV_MAX);
> +
> + if (iov_max <= 0) {
> + TAP_LOG(WARNING,
> + "_SC_IOV_MAX is not defined. Using %d as default\n",
> + TAP_IOV_DEFAULT_MAX);
> + iov_max = TAP_IOV_DEFAULT_MAX;
> + }
> uint16_t nb_desc = RTE_MIN(nb_rx_desc, iov_max - 1);
Looking at this a little more carefully.
1. Trivial: TAP_LOG() already adds a newline.
2. TAP device should not be silently reducing the number of receive descriptors.
3. TAP device be using IOV_MAX to set rx_descriptor limit. (in dev_info)
The ethdev would rx_queue_setup with any request for too large a value.
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [dpdk-dev] [PATCH v6] net/tap: fix missing _SC_IOV_MAX
2019-03-18 17:56 ` Stephen Hemminger
@ 2019-03-18 17:56 ` Stephen Hemminger
0 siblings, 0 replies; 4+ messages in thread
From: Stephen Hemminger @ 2019-03-18 17:56 UTC (permalink / raw)
To: olegpoly123; +Cc: keith.wiles, thomas, dev, stable
On Mon, 18 Mar 2019 12:55:23 -0400
olegpoly123 <olegp123@walla.co.il> wrote:
> long iov_max = sysconf(_SC_IOV_MAX);
> +
> + if (iov_max <= 0) {
> + TAP_LOG(WARNING,
> + "_SC_IOV_MAX is not defined. Using %d as default\n",
> + TAP_IOV_DEFAULT_MAX);
> + iov_max = TAP_IOV_DEFAULT_MAX;
> + }
> uint16_t nb_desc = RTE_MIN(nb_rx_desc, iov_max - 1);
Looking at this a little more carefully.
1. Trivial: TAP_LOG() already adds a newline.
2. TAP device should not be silently reducing the number of receive descriptors.
3. TAP device be using IOV_MAX to set rx_descriptor limit. (in dev_info)
The ethdev would rx_queue_setup with any request for too large a value.
^ permalink raw reply [flat|nested] 4+ messages in thread
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2019-03-18 16:55 [dpdk-dev] [PATCH v6] net/tap: fix missing _SC_IOV_MAX olegpoly123
2019-03-18 16:55 ` olegpoly123
2019-03-18 17:56 ` Stephen Hemminger
2019-03-18 17:56 ` Stephen Hemminger
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