search for: preempt_en

...weird, because xen_play_dead() is invoked in the cpu down path, whereas cpu_bringup() (as the name suggests) is useful in the cpu bringup path. Getting rid of xen_play_dead()'s dependency on cpu_bringup() helps in hooking on to the generic SMP booting framework. Also remove the extra call to preempt_enable() added by commit 41bd956 (xen/smp: Fix CPU online/offline bug triggering a BUG: scheduling while atomic) because it becomes unnecessary after this change. Cc: Konrad Rzeszutek Wilk <konrad.wilk at oracle.com> Cc: Jeremy Fitzhardinge <jeremy at goop.org> Cc: Thomas Gleixner <tgl...

...weird, because xen_play_dead() is invoked in the cpu down path, whereas cpu_bringup() (as the name suggests) is useful in the cpu bringup path. Getting rid of xen_play_dead()'s dependency on cpu_bringup() helps in hooking on to the generic SMP booting framework. Also remove the extra call to preempt_enable() added by commit 41bd956 (xen/smp: Fix CPU online/offline bug triggering a BUG: scheduling while atomic) because it becomes unnecessary after this change. Cc: Konrad Rzeszutek Wilk <konrad.wilk at oracle.com> Cc: Jeremy Fitzhardinge <jeremy at goop.org> Cc: Thomas Gleixner <tgl...

...et.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c index 06d0448..1b68253 100644 --- a/drivers/vhost/net.c +++ b/drivers/vhost/net.c @@ -634,7 +634,7 @@ static int vhost_net_rx_peek_head_len(struct vhost_net *net, struct sock *sk) preempt_enable(); - if (vhost_enable_notify(&net->dev, vq)) + if (!vhost_vq_avail_empty(&net->dev, vq)) vhost_poll_queue(&vq->poll); mutex_unlock(&vq->mutex); -- 2.7.4

...et.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c index 06d0448..1b68253 100644 --- a/drivers/vhost/net.c +++ b/drivers/vhost/net.c @@ -634,7 +634,7 @@ static int vhost_net_rx_peek_head_len(struct vhost_net *net, struct sock *sk) preempt_enable(); - if (vhost_enable_notify(&net->dev, vq)) + if (!vhost_vq_avail_empty(&net->dev, vq)) vhost_poll_queue(&vq->poll); mutex_unlock(&vq->mutex); -- 2.7.4

...+ > + preempt_disable(); > + endtime = busy_clock() + busyloop_timeout; > + while (vhost_can_busy_poll(tvq->dev, endtime) && > + !(sock && sk_has_rx_data(sock->sk)) && > + vhost_vq_avail_empty(tvq->dev, tvq)) > + cpu_relax(); > + preempt_enable(); > + > + if ((rx && !vhost_vq_avail_empty(&net->dev, vq)) || > + (!rx && (sock && sk_has_rx_data(sock->sk)))) { > + vhost_poll_queue(&vq->poll); > + } else if (unlikely(vhost_enable_notify(&net->dev, vq))) { One last questio...

...+ > + preempt_disable(); > + endtime = busy_clock() + busyloop_timeout; > + while (vhost_can_busy_poll(tvq->dev, endtime) && > + !(sock && sk_has_rx_data(sock->sk)) && > + vhost_vq_avail_empty(tvq->dev, tvq)) > + cpu_relax(); > + preempt_enable(); > + > + if ((rx && !vhost_vq_avail_empty(&net->dev, vq)) || > + (!rx && (sock && sk_has_rx_data(sock->sk)))) { > + vhost_poll_queue(&vq->poll); > + } else if (unlikely(vhost_enable_notify(&net->dev, vq))) { One last questio...

...mic(addr) \ -do { \ - BUILD_BUG_ON(__same_type((addr), struct page *)); \ - kunmap_atomic_high(addr); \ - pagefault_enable(); \ - preempt_enable(); \ +#define kunmap_atomic(__addr) \ +do { \ + BUILD_BUG_ON(__same_type((__addr), struct page *)); \ + __kunmap_atomic(__addr); \ + pagefault_enable(); \ + preempt_enable(); \ } while (0) - /* when CONFIG_HIGHMEM is not set these...

On 2018?08?01? 17:52, Tonghao Zhang wrote: >>> + >>> + cpu_relax(); >>> + } >>> + >>> + preempt_enable(); >>> + >>> + if (!rx) >>> + vhost_net_enable_vq(net, vq); >> No need to enable rx virtqueue, if we are sure handle_rx() will be >> called soon. > If we disable rx virtqueue in handle_tx and don't send packets from > guest anymor...

On 2018?08?01? 17:52, Tonghao Zhang wrote: >>> + >>> + cpu_relax(); >>> + } >>> + >>> + preempt_enable(); >>> + >>> + if (!rx) >>> + vhost_net_enable_vq(net, vq); >> No need to enable rx virtqueue, if we are sure handle_rx() will be >> called soon. > If we disable rx virtqueue in handle_tx and don't send packets from > guest anymor...

...k->sk) && > + !vhost_vq_avail_empty(&net->dev, rvq)) || > + !vhost_vq_avail_empty(&net->dev, tvq)) > + break; Some checks were duplicated in vhost_net_busy_poll_check(). Need consider to unify them. > + > + cpu_relax(); > + } > + > + preempt_enable(); > + > + if (!rx) > + vhost_net_enable_vq(net, vq); No need to enable rx virtqueue, if we are sure handle_rx() will be called soon. > + > + vhost_net_busy_poll_check(net, rvq, tvq, rx); It looks to me just open code all check here is better and easier to be reviewed. Tha...

...k->sk) && > + !vhost_vq_avail_empty(&net->dev, rvq)) || > + !vhost_vq_avail_empty(&net->dev, tvq)) > + break; Some checks were duplicated in vhost_net_busy_poll_check(). Need consider to unify them. > + > + cpu_relax(); > + } > + > + preempt_enable(); > + > + if (!rx) > + vhost_net_enable_vq(net, vq); No need to enable rx virtqueue, if we are sure handle_rx() will be called soon. > + > + vhost_net_busy_poll_check(net, rvq, tvq, rx); It looks to me just open code all check here is better and easier to be reviewed. Tha...

...+ > + preempt_disable(); > + endtime = busy_clock() + busyloop_timeout; > + while (vhost_can_busy_poll(tvq->dev, endtime) && > + !(sock && sk_has_rx_data(sock->sk)) && > + vhost_vq_avail_empty(tvq->dev, tvq)) > + cpu_relax(); > + preempt_enable(); > + > + if ((rx && !vhost_vq_avail_empty(&net->dev, vq)) || > + (!rx && (sock && sk_has_rx_data(sock->sk)))) { > + vhost_poll_queue(&vq->poll); > + } else if (vhost_enable_notify(&net->dev, vq) && rx) { Hmm... on tx...

...+ > + preempt_disable(); > + endtime = busy_clock() + busyloop_timeout; > + while (vhost_can_busy_poll(tvq->dev, endtime) && > + !(sock && sk_has_rx_data(sock->sk)) && > + vhost_vq_avail_empty(tvq->dev, tvq)) > + cpu_relax(); > + preempt_enable(); > + > + if ((rx && !vhost_vq_avail_empty(&net->dev, vq)) || > + (!rx && (sock && sk_has_rx_data(sock->sk)))) { > + vhost_poll_queue(&vq->poll); > + } else if (vhost_enable_notify(&net->dev, vq) && rx) { Hmm... on tx...

...+ > + preempt_disable(); > + endtime = busy_clock() + busyloop_timeout; > + while (vhost_can_busy_poll(tvq->dev, endtime) && > + !(sock && sk_has_rx_data(sock->sk)) && > + vhost_vq_avail_empty(tvq->dev, tvq)) > + cpu_relax(); > + preempt_enable(); > + > + if ((rx && !vhost_vq_avail_empty(&net->dev, vq)) || > + (!rx && (sock && sk_has_rx_data(sock->sk)))) { > + vhost_poll_queue(&vq->poll); > + } else if (unlikely(vhost_enable_notify(&net->dev, vq))) { > + vhost_dis...

Hi all: We do not support XDP batching for TUN since it can only receive one packet a time from vhost_net. This series tries to remove this limitation by: - introduce a TUN specific msg_control that can hold a pointer to an array of XDP buffs - try copy and build XDP buff in vhost_net - store XDP buffs in an array and submit them once for every N packets from vhost_net - since TUN can only

...op_timeout; >>> + while (vhost_can_busy_poll(tvq->dev, endtime) && >>> + !(sock && sk_has_rx_data(sock->sk)) && >>> + vhost_vq_avail_empty(tvq->dev, tvq)) >>> + cpu_relax(); >>> + preempt_enable(); >>> + >>> + if ((rx && !vhost_vq_avail_empty(&net->dev, vq)) || >>> + (!rx && (sock && sk_has_rx_data(sock->sk)))) { >>> + vhost_poll_queue(&vq->poll); >>> + } else if (unlikely(...

From: Tonghao Zhang <xiangxia.m.yue at gmail.com> This patches improve the guest receive and transmit performance. On the handle_tx side, we poll the sock receive queue at the same time. handle_rx do that in the same way. For more performance report, see patch 4. v3 -> v4: fix some issues v2 -> v3: This patches are splited from previous big patch:

...omap.h @@ -13,14 +13,7 @@ #include <asm/cacheflush.h> #include <asm/tlbflush.h> -void __iomem *iomap_atomic_pfn_prot(unsigned long pfn, pgprot_t prot); - -static inline void iounmap_atomic(void __iomem *vaddr) -{ - kunmap_local_indexed((void __force *)vaddr); - pagefault_enable(); - preempt_enable(); -} +void __iomem *__iomap_local_pfn_prot(unsigned long pfn, pgprot_t prot); int iomap_create_wc(resource_size_t base, unsigned long size, pgprot_t *prot); --- a/arch/x86/mm/iomap_32.c +++ b/arch/x86/mm/iomap_32.c @@ -44,7 +44,7 @@ void iomap_free(resource_size_t base, un } EXPORT_SYMB...

...644 > --- a/drivers/vhost/net.c > +++ b/drivers/vhost/net.c > @@ -634,7 +634,7 @@ static int vhost_net_rx_peek_head_len(struct vhost_net *net, struct sock *sk) In fact why does it poll the ring at all? I thought this function's job is to poll the socket, isn't it? > > preempt_enable(); > > - if (vhost_enable_notify(&net->dev, vq)) > + if (!vhost_vq_avail_empty(&net->dev, vq)) > vhost_poll_queue(&vq->poll); > mutex_unlock(&vq->mutex); Adding more contex: mutex_lock(&vq->mutex); v...

...ged, 2 insertions(+), 3 deletions(-) diff --git a/drivers/net/tun.c b/drivers/net/tun.c index 44d4f3d..24ecd82 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -1697,6 +1697,8 @@ static struct sk_buff *tun_build_skb(struct tun_struct *tun, goto err_xdp; } } + rcu_read_unlock(); + preempt_enable(); skb = build_skb(buf, buflen); if (!skb) { @@ -1710,9 +1712,6 @@ static struct sk_buff *tun_build_skb(struct tun_struct *tun, get_page(alloc_frag->page); alloc_frag->offset += buflen; - rcu_read_unlock(); - preempt_enable(); - return skb; err_redirect: -- 2.7.4