search for: tun_do_read

...rivers/net/tun.c | 24 ++++++++++++++++++------ > 1 file changed, 18 insertions(+), 6 deletions(-) > > diff --git a/drivers/net/tun.c b/drivers/net/tun.c > index 9574900..4f4a842 100644 > --- a/drivers/net/tun.c > +++ b/drivers/net/tun.c > @@ -1952,8 +1952,11 @@ static ssize_t tun_do_read(struct tun_struct *tun, struct tun_file *tfile, > > tun_debug(KERN_INFO, tun, "tun_do_read\n"); > > - if (!iov_iter_count(to)) > + if (!iov_iter_count(to)) { > + if (skb) > + kfree_skb(skb); > return 0; > + } > > if (!skb) { > /* Read...

...o at linux.vnet.ibm.com> --- drivers/net/tun.c | 24 ++++++++++++++++++------ 1 file changed, 18 insertions(+), 6 deletions(-) diff --git a/drivers/net/tun.c b/drivers/net/tun.c index 9574900..4f4a842 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -1952,8 +1952,11 @@ static ssize_t tun_do_read(struct tun_struct *tun, struct tun_file *tfile, tun_debug(KERN_INFO, tun, "tun_do_read\n"); - if (!iov_iter_count(to)) + if (!iov_iter_count(to)) { + if (skb) + kfree_skb(skb); return 0; + } if (!skb) { /* Read frames from ring */ @@ -2069,22 +2072,24 @@ static int tun_...

From: Wei Xu <wexu at redhat.com> Matthew found a roughly 40% tcp throughput regression with commit c67df11f(vhost_net: try batch dequing from skb array) as discussed in the following thread: https://www.mail-archive.com/netdev at vger.kernel.org/msg187936.html v4: - fix zero iov iterator count in tap/tap_do_read()(Jason) - don't put tun in case of EBADFD(Jason) - Replace

From: Wei Xu <wexu at redhat.com> Matthew found a roughly 40% tcp throughput regression with commit c67df11f(vhost_net: try batch dequing from skb array) as discussed in the following thread: https://www.mail-archive.com/netdev at vger.kernel.org/msg187936.html v4: - fix zero iov iterator count in tap/tap_do_read()(Jason) - don't put tun in case of EBADFD(Jason) - Replace

We always poll tx for socket, this is sub optimal since: - we only want to be notified when sndbuf is available - this will slightly increase the waitqueue traversing time and more important, vhost could not benefit from commit commit 9e641bdcfa4e ("net-tun: restructure tun_do_read for better sleep/wakeup efficiency") even if we've stopped rx polling during handle_rx() since tx poll were still left in the waitqueue. Pktgen from a remote host to VM over mlx4 shows 5.5% improvements on rx PPS. (from 1.27Mpps to 1.34Mpps) Cc: Wei Xu <wexu at redhat.com> Cc:...

We always poll tx for socket, this is sub optimal since: - we only want to be notified when sndbuf is available - this will slightly increase the waitqueue traversing time and more important, vhost could not benefit from commit commit 9e641bdcfa4e ("net-tun: restructure tun_do_read for better sleep/wakeup efficiency") even if we've stopped rx polling during handle_rx() since tx poll were still left in the waitqueue. Pktgen from a remote host to VM over mlx4 shows 5.5% improvements on rx PPS. (from 1.27Mpps to 1.34Mpps) Cc: Wei Xu <wexu at redhat.com> Cc:...

...tats.tx_packets++; tun->dev->stats.tx_bytes += len; @@ -751,34 +754,23 @@ static __inline__ ssize_t tun_put_user(struct tun_struct *tun, return total; } -static ssize_t tun_chr_aio_read(struct kiocb *iocb, const struct iovec *iv, - unsigned long count, loff_t pos) +static ssize_t tun_do_read(struct tun_struct *tun, + struct kiocb *iocb, const struct iovec *iv, + ssize_t len, int noblock) { - struct file *file = iocb->ki_filp; - struct tun_file *tfile = file->private_data; - struct tun_struct *tun = __tun_get(tfile); DECLARE_WAITQUEUE(wait, current); struct sk_buff...

...tats.tx_packets++; tun->dev->stats.tx_bytes += len; @@ -751,34 +754,23 @@ static __inline__ ssize_t tun_put_user(struct tun_struct *tun, return total; } -static ssize_t tun_chr_aio_read(struct kiocb *iocb, const struct iovec *iv, - unsigned long count, loff_t pos) +static ssize_t tun_do_read(struct tun_struct *tun, + struct kiocb *iocb, const struct iovec *iv, + ssize_t len, int noblock) { - struct file *file = iocb->ki_filp; - struct tun_file *tfile = file->private_data; - struct tun_struct *tun = __tun_get(tfile); DECLARE_WAITQUEUE(wait, current); struct sk_buff...

...tats.tx_packets++; tun->dev->stats.tx_bytes += len; @@ -751,34 +754,23 @@ static __inline__ ssize_t tun_put_user(struct tun_struct *tun, return total; } -static ssize_t tun_chr_aio_read(struct kiocb *iocb, const struct iovec *iv, - unsigned long count, loff_t pos) +static ssize_t tun_do_read(struct tun_struct *tun, + struct kiocb *iocb, const struct iovec *iv, + ssize_t len, int noblock) { - struct file *file = iocb->ki_filp; - struct tun_file *tfile = file->private_data; - struct tun_struct *tun = __tun_get(tfile); DECLARE_WAITQUEUE(wait, current); struct sk_buff...

...tats.tx_packets++; tun->dev->stats.tx_bytes += len; @@ -751,34 +754,23 @@ static __inline__ ssize_t tun_put_user(struct tun_struct *tun, return total; } -static ssize_t tun_chr_aio_read(struct kiocb *iocb, const struct iovec *iv, - unsigned long count, loff_t pos) +static ssize_t tun_do_read(struct tun_struct *tun, + struct kiocb *iocb, const struct iovec *iv, + ssize_t len, int noblock) { - struct file *file = iocb->ki_filp; - struct tun_file *tfile = file->private_data; - struct tun_struct *tun = __tun_get(tfile); DECLARE_WAITQUEUE(wait, current); struct sk_buff...

...xceed the sndbuf of the socket. > - since we use two independent polls for tx and vq, this will slightly > increase the waitqueue traversing time and more important, vhost > could not benefit from commit > 9e641bdcfa4ef4d6e2fbaa59c1be0ad5d1551fd5 ("net-tun: restructure > tun_do_read for better sleep/wakeup efficiency") even if we've > stopped rx polling during handle_rx since tx poll were still left in > the waitqueue. > > Fix this by conditionally enable tx polling only when -EAGAIN were > met. > > Test shows about 8% improvement on guest r...

...xceed the sndbuf of the socket. > - since we use two independent polls for tx and vq, this will slightly > increase the waitqueue traversing time and more important, vhost > could not benefit from commit > 9e641bdcfa4ef4d6e2fbaa59c1be0ad5d1551fd5 ("net-tun: restructure > tun_do_read for better sleep/wakeup efficiency") even if we've > stopped rx polling during handle_rx since tx poll were still left in > the waitqueue. > > Fix this by conditionally enable tx polling only when -EAGAIN were > met. > > Test shows about 8% improvement on guest r...

...tats.tx_packets++; tun->dev->stats.tx_bytes += len; @@ -751,34 +754,23 @@ static __inline__ ssize_t tun_put_user(struct tun_struct *tun, return total; } -static ssize_t tun_chr_aio_read(struct kiocb *iocb, const struct iovec *iv, - unsigned long count, loff_t pos) +static ssize_t tun_do_read(struct tun_struct *tun, + struct kiocb *iocb, const struct iovec *iv, + ssize_t len, int noblock) { - struct file *file = iocb->ki_filp; - struct tun_file *tfile = file->private_data; - struct tun_struct *tun = __tun_get(tfile); DECLARE_WAITQUEUE(wait, current); struct sk_buff...

...tats.tx_packets++; tun->dev->stats.tx_bytes += len; @@ -751,34 +754,23 @@ static __inline__ ssize_t tun_put_user(struct tun_struct *tun, return total; } -static ssize_t tun_chr_aio_read(struct kiocb *iocb, const struct iovec *iv, - unsigned long count, loff_t pos) +static ssize_t tun_do_read(struct tun_struct *tun, + struct kiocb *iocb, const struct iovec *iv, + ssize_t len, int noblock) { - struct file *file = iocb->ki_filp; - struct tun_file *tfile = file->private_data; - struct tun_struct *tun = __tun_get(tfile); DECLARE_WAITQUEUE(wait, current); struct sk_buff...

...xceed the sndbuf of the socket. > - since we use two independent polls for tx and vq, this will slightly > increase the waitqueue traversing time and more important, vhost > could not benefit from commit > 9e641bdcfa4ef4d6e2fbaa59c1be0ad5d1551fd5 ("net-tun: restructure > tun_do_read for better sleep/wakeup efficiency") even if we've > stopped rx polling during handle_rx since tx poll were still left in > the waitqueue. Why is this an issue? sock_def_write_space only wakes up when queue is half empty, not on each packet. if ((atomic_read(&sk->...

...xceed the sndbuf of the socket. > - since we use two independent polls for tx and vq, this will slightly > increase the waitqueue traversing time and more important, vhost > could not benefit from commit > 9e641bdcfa4ef4d6e2fbaa59c1be0ad5d1551fd5 ("net-tun: restructure > tun_do_read for better sleep/wakeup efficiency") even if we've > stopped rx polling during handle_rx since tx poll were still left in > the waitqueue. Why is this an issue? sock_def_write_space only wakes up when queue is half empty, not on each packet. if ((atomic_read(&sk->...

...ub optimal since: >> >> - we only want to be notified when sndbuf is available >> - this will slightly increase the waitqueue traversing time and more >> important, vhost could not benefit from commit >> commit 9e641bdcfa4e >> ("net-tun: restructure tun_do_read for better sleep/wakeup efficiency") >> even if we've stopped rx polling during handle_rx() since tx poll >> were still left in the waitqueue. >> >> Pktgen from a remote host to VM over mlx4 shows 5.5% improvements on >> rx PPS. (from 1.27Mpps to 1.34Mpp...

...ub optimal since: >> >> - we only want to be notified when sndbuf is available >> - this will slightly increase the waitqueue traversing time and more >> important, vhost could not benefit from commit >> commit 9e641bdcfa4e >> ("net-tun: restructure tun_do_read for better sleep/wakeup efficiency") >> even if we've stopped rx polling during handle_rx() since tx poll >> were still left in the waitqueue. >> >> Pktgen from a remote host to VM over mlx4 shows 5.5% improvements on >> rx PPS. (from 1.27Mpps to 1.34Mpp...

Hi all: This series tries to implement rx batching for vhost-net. This is done by batching the dequeuing from skb_array which was exported by underlayer socket and pass the sbk back through msg_control to finish userspace copying. Tests shows at most 19% improvment on rx pps. Please review. Thanks Jason Wang (8): ptr_ring: introduce batch dequeuing skb_array: introduce batch dequeuing

Hi all: This series tries to implement rx batching for vhost-net. This is done by batching the dequeuing from skb_array which was exported by underlayer socket and pass the sbk back through msg_control to finish userspace copying. Tests shows at most 19% improvment on rx pps. Please review. Thanks Jason Wang (8): ptr_ring: introduce batch dequeuing skb_array: introduce batch dequeuing