search for: napi_en

...<brogers at novell.com> Under harsh testing conditions, including low memory, the guest would stop receiving packets. With this patch applied we no longer see any problems in the driver while performing these tests for extended periods of time. Make sure napi is scheduled subsequent to each napi_enable. Signed-off-by: Bruce Rogers <brogers at novell.com> Signed-off-by: Olaf Kirch <okir at suse.de> Cc: stable at kernel.org Signed-off-by: Rusty Russell <rusty at rustcorp.com.au> --- drivers/net/virtio_net.c | 27 ++++++++++++++++----------- 1 file changed, 16 insertions(+)...

...<brogers at novell.com> Under harsh testing conditions, including low memory, the guest would stop receiving packets. With this patch applied we no longer see any problems in the driver while performing these tests for extended periods of time. Make sure napi is scheduled subsequent to each napi_enable. Signed-off-by: Bruce Rogers <brogers at novell.com> Signed-off-by: Olaf Kirch <okir at suse.de> Cc: stable at kernel.org Signed-off-by: Rusty Russell <rusty at rustcorp.com.au> --- drivers/net/virtio_net.c | 27 ++++++++++++++++----------- 1 file changed, 16 insertions(+)...

Please consider this patch for the 2.6.32, 2.6.33, and 2.6.34 stable trees as well as current development trees. (I've only tested on 2.6.32 however) virtio_net: Add schedule check to napi_enable call Under harsh testing conditions, including low memory, the guest would stop receiving packets. With this patch applied we no longer see any problems in the driver while performing these tests for extended periods of time. Make sure napi is scheduled subsequent to each n...

Please consider this patch for the 2.6.32, 2.6.33, and 2.6.34 stable trees as well as current development trees. (I've only tested on 2.6.32 however) virtio_net: Add schedule check to napi_enable call Under harsh testing conditions, including low memory, the guest would stop receiving packets. With this patch applied we no longer see any problems in the driver while performing these tests for extended periods of time. Make sure napi is scheduled subsequent to each n...

...will copy more than 200GB unfailingly this way. See https://bugs.launchpad.net/bugs/579276 for more details. --- drivers/net/virtio_net.c.orig 2011-02-08 14:34:51.444099190 -0500 +++ drivers/net/virtio_net.c 2011-02-08 14:18:00.484400134 -0500 @@ -446,6 +446,20 @@ } } +static void virtnet_napi_enable(struct virtnet_info *vi) +{ + napi_enable(&vi->napi); + + /* If all buffers were filled by other side before we napi_enabled, we + * won't get another interrupt, so process any outstanding packets + * now. virtnet_poll wants re-enable the queue, so we disable here. + * We synchro...

...will copy more than 200GB unfailingly this way. See https://bugs.launchpad.net/bugs/579276 for more details. --- drivers/net/virtio_net.c.orig 2011-02-08 14:34:51.444099190 -0500 +++ drivers/net/virtio_net.c 2011-02-08 14:18:00.484400134 -0500 @@ -446,6 +446,20 @@ } } +static void virtnet_napi_enable(struct virtnet_info *vi) +{ + napi_enable(&vi->napi); + + /* If all buffers were filled by other side before we napi_enabled, we + * won't get another interrupt, so process any outstanding packets + * now. virtnet_poll wants re-enable the queue, so we disable here. + * We synchro...

Hello Rusty, while implementing and testing virtio on s390 I found a problem in virtio_net: The current virtio_net driver has a startup race, which prevents any incoming traffic: If try_fill_recv submits buffers to the host system data might be filled in and an interrupt is sent, before napi_enable finishes. In that case the interrupt will kick skb_recv_done which will then call netif_rx_schedule. netif_rx_schedule checks, if NAPI_STATE_SCHED is set - which is not as we did not run napi_enable. No poll routine is scheduled. Furthermore, skb_recv_done returns false, we disables interrupts...

Hello Rusty, while implementing and testing virtio on s390 I found a problem in virtio_net: The current virtio_net driver has a startup race, which prevents any incoming traffic: If try_fill_recv submits buffers to the host system data might be filled in and an interrupt is sent, before napi_enable finishes. In that case the interrupt will kick skb_recv_done which will then call netif_rx_schedule. netif_rx_schedule checks, if NAPI_STATE_SCHED is set - which is not as we did not run napi_enable. No poll routine is scheduled. Furthermore, skb_recv_done returns false, we disables interrupts...

...* fragments + linear part + virtio header */ struct scatterlist rx_sg[MAX_SKB_FRAGS + 2]; struct scatterlist tx_sg[MAX_SKB_FRAGS + 2]; + + /* Work struct for refilling if we run low on memory. */ + struct delayed_work refill; + + /* Whether napi is enabled, protected by a refill_lock. */ + bool napi_enable; + + /* Lock to protect refill and napi enable/disable operations. */ + struct mutex refill_lock; }; struct skb_vnet_hdr { @@ -494,14 +501,20 @@ static void refill_work(struct work_struct *work) bool still_empty; vi = container_of(work, struct virtnet_info, refill.work); - napi_disabl...

...* fragments + linear part + virtio header */ struct scatterlist rx_sg[MAX_SKB_FRAGS + 2]; struct scatterlist tx_sg[MAX_SKB_FRAGS + 2]; + + /* Work struct for refilling if we run low on memory. */ + struct delayed_work refill; + + /* Whether napi is enabled, protected by a refill_lock. */ + bool napi_enable; + + /* Lock to protect refill and napi enable/disable operations. */ + struct mutex refill_lock; }; struct skb_vnet_hdr { @@ -494,14 +501,20 @@ static void refill_work(struct work_struct *work) bool still_empty; vi = container_of(work, struct virtnet_info, refill.work); - napi_disabl...

...t scatterlist tx_sg[MAX_SKB_FRAGS + 2]; + + /* Work struct for refilling if we run low on memory. */ + struct delayed_work refill; + + /* Set flag to allow delayed refill work, protected by a refill_lock. */ + bool refill_enable; + + /* Whether napi is enabled, protected by a refill_lock. */ + bool napi_enable; + + /* Lock to protect refill and napi enable/disable operations. */ + struct mutex refill_lock; }; struct skb_vnet_hdr { @@ -477,20 +487,35 @@ static void virtnet_napi_enable(struct virtnet_info *vi) } } +static void virtnet_refill_enable(struct virtnet_info *vi, bool enable) +{ + mu...

...t scatterlist tx_sg[MAX_SKB_FRAGS + 2]; + + /* Work struct for refilling if we run low on memory. */ + struct delayed_work refill; + + /* Set flag to allow delayed refill work, protected by a refill_lock. */ + bool refill_enable; + + /* Whether napi is enabled, protected by a refill_lock. */ + bool napi_enable; + + /* Lock to protect refill and napi enable/disable operations. */ + struct mutex refill_lock; }; struct skb_vnet_hdr { @@ -477,20 +487,35 @@ static void virtnet_napi_enable(struct virtnet_info *vi) } } +static void virtnet_refill_enable(struct virtnet_info *vi, bool enable) +{ + mu...

The current virtio_net driver has a startup race, which prevents any incoming traffic: If try_fill_recv submits buffers to the host system data might be filled in and an interrupt is sent, before napi_enable finishes. In that case the interrupt will kick skb_recv_done which will then call netif_rx_schedule. netif_rx_schedule checks, if NAPI_STATE_SCHED is set - which is not as we did not run napi_enable. No poll routine is scheduled. Furthermore, skb_recv_done returns false, we disables interrupts...

The current virtio_net driver has a startup race, which prevents any incoming traffic: If try_fill_recv submits buffers to the host system data might be filled in and an interrupt is sent, before napi_enable finishes. In that case the interrupt will kick skb_recv_done which will then call netif_rx_schedule. netif_rx_schedule checks, if NAPI_STATE_SCHED is set - which is not as we did not run napi_enable. No poll routine is scheduled. Furthermore, skb_recv_done returns false, we disables interrupts...

From: Willem de Bruijn <willemb at google.com> As of tx napi, device down (`ip link set dev $dev down`) hangs unless tx napi is enabled. Else napi_enable is not called, so napi_disable will spin on test_and_set_bit NAPI_STATE_SCHED. Only call napi_disable if tx napi is enabled. Fixes: 5a719c2552ca ("virtio-net: transmit napi") Reported-by: Jason Wang <jasowang at redhat.com> Signed-off-by: Willem de Bruijn <willemb at google...

From: Willem de Bruijn <willemb at google.com> As of tx napi, device down (`ip link set dev $dev down`) hangs unless tx napi is enabled. Else napi_enable is not called, so napi_disable will spin on test_and_set_bit NAPI_STATE_SCHED. Only call napi_disable if tx napi is enabled. Fixes: 5a719c2552ca ("virtio-net: transmit napi") Reported-by: Jason Wang <jasowang at redhat.com> Signed-off-by: Willem de Bruijn <willemb at google...

From: Willem de Bruijn <willemb at google.com> Add napi for virtio-net transmit completion processing. Based on previous patchsets by Jason Wang: [RFC V7 PATCH 0/7] enable tx interrupts for virtio-net http://lkml.iu.edu/hypermail/linux/kernel/1505.3/00245.html Changes: RFC -> v1: - dropped vhost interrupt moderation patch: not needed and likely expensive at light

From: Willem de Bruijn <willemb at google.com> Add napi for virtio-net transmit completion processing. Based on previous patchsets by Jason Wang: [RFC V7 PATCH 0/7] enable tx interrupts for virtio-net http://lkml.iu.edu/hypermail/linux/kernel/1505.3/00245.html Changes: RFC -> v1: - dropped vhost interrupt moderation patch: not needed and likely expensive at light

...if (i < vi->curr_queue_pairs) /* Make sure we have some buffers: if oom use wq. */ if (!try_fill_recv(&vi->rq[i], GFP_KERNEL)) schedule_delayed_work(&vi->refill, 0); virtnet_napi_enable(&vi->rq[i]); What if the workqueue is scheduled _before_ the call to virtnet_napi_enable(&vi->rq[i]) ? refill_work() will happily conflict with another cpu, two cpus could call try_fill_recv() at the same time, or worse napi_enable() would crash. I do not have time to make a...

...if (i < vi->curr_queue_pairs) /* Make sure we have some buffers: if oom use wq. */ if (!try_fill_recv(&vi->rq[i], GFP_KERNEL)) schedule_delayed_work(&vi->refill, 0); virtnet_napi_enable(&vi->rq[i]); What if the workqueue is scheduled _before_ the call to virtnet_napi_enable(&vi->rq[i]) ? refill_work() will happily conflict with another cpu, two cpus could call try_fill_recv() at the same time, or worse napi_enable() would crash. I do not have time to make a...