search for: synchonrize

Hi all: This series introduces the support for rx busy polling support. This was useful for reduing the latency for a kvm guest. Instead of introducing new states and spinlocks, this series re-uses NAPI state to synchonrize between NAPI and busy polling. This grealy simplified the codes and reduce the overheads of spinlocks for normal NAPI fast path. Test was done between a kvm guest and an external host. Two hosts were connected through 40gb mlx4 cards. With both busy_poll and busy_read are set to 50 in guest, 1 by...

Hi all: This series introduces the support for rx busy polling support. This was useful for reduing the latency for a kvm guest. Instead of introducing new states and spinlocks, this series re-uses NAPI state to synchonrize between NAPI and busy polling. This grealy simplified the codes and reduce the overheads of spinlocks for normal NAPI fast path. Test was done between a kvm guest and an external host. Two hosts were connected through 40gb mlx4 cards. With both busy_poll and busy_read are set to 50 in guest, 1 by...

.../vhost/vhost.h index a9a2a93857d2..12399e7c7a61 100644 --- a/drivers/vhost/vhost.h +++ b/drivers/vhost/vhost.h @@ -115,16 +115,17 @@ struct vhost_virtqueue { #if VHOST_ARCH_CAN_ACCEL_UACCESS /* Read by memory accessors, modified by meta data * prefetching, MMU notifier and vring ioctl(). - * Synchonrized through mmu_lock (writers) and RCU (writers - * and readers). + * Synchonrized through mmu_lock (writers) and seqlock + * counters, see vhost_vq_access_map_{begin|end}(). */ - struct vhost_map __rcu *maps[VHOST_NUM_ADDRS]; + struct vhost_map *maps[VHOST_NUM_ADDRS]; /* Read by MMU n...

.../vhost/vhost.h index a9a2a93857d2..f9e9558a529d 100644 --- a/drivers/vhost/vhost.h +++ b/drivers/vhost/vhost.h @@ -115,16 +115,17 @@ struct vhost_virtqueue { #if VHOST_ARCH_CAN_ACCEL_UACCESS /* Read by memory accessors, modified by meta data * prefetching, MMU notifier and vring ioctl(). - * Synchonrized through mmu_lock (writers) and RCU (writers - * and readers). + * Synchonrized through mmu_lock (writers) and ref counters, + * see vhost_vq_access_map_begin()/vhost_vq_access_map_end(). */ - struct vhost_map __rcu *maps[VHOST_NUM_ADDRS]; + struct vhost_map *maps[VHOST_NUM_ADDRS]; /* Read...

...f9e9558a529d 100644 > --- a/drivers/vhost/vhost.h > +++ b/drivers/vhost/vhost.h > @@ -115,16 +115,17 @@ struct vhost_virtqueue { > #if VHOST_ARCH_CAN_ACCEL_UACCESS > /* Read by memory accessors, modified by meta data > * prefetching, MMU notifier and vring ioctl(). > - * Synchonrized through mmu_lock (writers) and RCU (writers > - * and readers). > + * Synchonrized through mmu_lock (writers) and ref counters, > + * see vhost_vq_access_map_begin()/vhost_vq_access_map_end(). > */ > - struct vhost_map __rcu *maps[VHOST_NUM_ADDRS]; > + struct vhost_map *map...

...f9e9558a529d 100644 > --- a/drivers/vhost/vhost.h > +++ b/drivers/vhost/vhost.h > @@ -115,16 +115,17 @@ struct vhost_virtqueue { > #if VHOST_ARCH_CAN_ACCEL_UACCESS > /* Read by memory accessors, modified by meta data > * prefetching, MMU notifier and vring ioctl(). > - * Synchonrized through mmu_lock (writers) and RCU (writers > - * and readers). > + * Synchonrized through mmu_lock (writers) and ref counters, > + * see vhost_vq_access_map_begin()/vhost_vq_access_map_end(). > */ > - struct vhost_map __rcu *maps[VHOST_NUM_ADDRS]; > + struct vhost_map *map...

Hi all: This series try to fix several issues introduced by meta data accelreation series. Please review. Changes from V1: - Try not use RCU to syncrhonize MMU notifier with vhost worker - set dirty pages after no readers - return -EAGAIN only when we find the range is overlapped with metadata Jason Wang (9): vhost: don't set uaddr for invalid address vhost: validate MMU notifier

...e { @@ -109,7 +110,7 @@ struct vhost_virtqueue { struct vring_avail __user *avail; struct vring_used __user *used; -#if VHOST_ARCH_CAN_ACCEL_UACCESS +#ifdef VHOST_ARCH_CAN_ACCEL_UACCESS /* Read by memory accessors, modified by meta data * prefetching, MMU notifier and vring ioctl(). * Synchonrized through mmu_lock (writers) and RCU (writers -- 2.22.0.rc3

...e { @@ -109,7 +110,7 @@ struct vhost_virtqueue { struct vring_avail __user *avail; struct vring_used __user *used; -#if VHOST_ARCH_CAN_ACCEL_UACCESS +#ifdef VHOST_ARCH_CAN_ACCEL_UACCESS /* Read by memory accessors, modified by meta data * prefetching, MMU notifier and vring ioctl(). * Synchonrized through mmu_lock (writers) and RCU (writers -- 2.22.0.rc3

...gt; >> +++ b/drivers/vhost/vhost.h > >> @@ -115,16 +115,17 @@ struct vhost_virtqueue { > >> #if VHOST_ARCH_CAN_ACCEL_UACCESS > >> /* Read by memory accessors, modified by meta data > >> * prefetching, MMU notifier and vring ioctl(). > >> - * Synchonrized through mmu_lock (writers) and RCU (writers > >> - * and readers). > >> + * Synchonrized through mmu_lock (writers) and ref counters, > >> + * see vhost_vq_access_map_begin()/vhost_vq_access_map_end(). > >> */ > >> - struct vhost_map __rcu *maps[V...

...--- a/drivers/vhost/vhost.h >> +++ b/drivers/vhost/vhost.h >> @@ -115,16 +115,17 @@ struct vhost_virtqueue { >> #if VHOST_ARCH_CAN_ACCEL_UACCESS >> /* Read by memory accessors, modified by meta data >> * prefetching, MMU notifier and vring ioctl(). >> - * Synchonrized through mmu_lock (writers) and RCU (writers >> - * and readers). >> + * Synchonrized through mmu_lock (writers) and ref counters, >> + * see vhost_vq_access_map_begin()/vhost_vq_access_map_end(). >> */ >> - struct vhost_map __rcu *maps[VHOST_NUM_ADDRS]; >>...

...tqueue { > struct vring_avail __user *avail; > struct vring_used __user *used; > > -#if VHOST_ARCH_CAN_ACCEL_UACCESS > +#ifdef VHOST_ARCH_CAN_ACCEL_UACCESS > /* Read by memory accessors, modified by meta data > * prefetching, MMU notifier and vring ioctl(). > * Synchonrized through mmu_lock (writers) and RCU (writers > -- > 2.22.0.rc3 I'd prefer just changing the definition. ifdefs have a disadvantage that it's easy to get wrong code if you forget to include a header. I queued the below - pls confirm it works for you. diff --git a/drivers/vhost/v...

Hi all: This series try to fix several issues introduced by meta data accelreation series. Please review. Changes from V2: - use seqlck helper to synchronize MMU notifier with vhost worker Changes from V1: - try not use RCU to syncrhonize MMU notifier with vhost worker - set dirty pages after no readers - return -EAGAIN only when we find the range is overlapped with metadata Jason Wang (9):

Hi all: This series try to fix several issues introduced by meta data accelreation series. Please review. Changes from V4: - switch to use spinlock synchronize MMU notifier with accessors Changes from V3: - remove the unnecessary patch Changes from V2: - use seqlck helper to synchronize MMU notifier with vhost worker Changes from V1: - try not use RCU to syncrhonize MMU notifier with vhost

Hi all: This series try to fix several issues introduced by meta data accelreation series. Please review. Changes from V4: - switch to use spinlock synchronize MMU notifier with accessors Changes from V3: - remove the unnecessary patch Changes from V2: - use seqlck helper to synchronize MMU notifier with vhost worker Changes from V1: - try not use RCU to syncrhonize MMU notifier with vhost

Hi all: This series try to fix several issues introduced by meta data accelreation series. Please review. Changes from V3: - remove the unnecessary patch Changes from V2: - use seqlck helper to synchronize MMU notifier with vhost worker Changes from V1: - try not use RCU to syncrhonize MMU notifier with vhost worker - set dirty pages after no readers - return -EAGAIN only when we find the

Hi all: This series try to fix several issues introduced by meta data accelreation series. Please review. Changes from V3: - remove the unnecessary patch Changes from V2: - use seqlck helper to synchronize MMU notifier with vhost worker Changes from V1: - try not use RCU to syncrhonize MMU notifier with vhost worker - set dirty pages after no readers - return -EAGAIN only when we find the

...virtqueue { > struct vring_desc __user *desc; > struct vring_avail __user *avail; > struct vring_used __user *used; > - > -#if VHOST_ARCH_CAN_ACCEL_UACCESS > - /* Read by memory accessors, modified by meta data > - * prefetching, MMU notifier and vring ioctl(). > - * Synchonrized through mmu_lock (writers) and RCU (writers > - * and readers). > - */ > - struct vhost_map __rcu *maps[VHOST_NUM_ADDRS]; > - /* Read by MMU notifier, modified by vring ioctl(), > - * synchronized through MMU notifier > - * registering/unregistering. > - */ > - struct...

...*dev; @@ -111,22 +90,7 @@ struct vhost_virtqueue { struct vring_desc __user *desc; struct vring_avail __user *avail; struct vring_used __user *used; - -#if VHOST_ARCH_CAN_ACCEL_UACCESS - /* Read by memory accessors, modified by meta data - * prefetching, MMU notifier and vring ioctl(). - * Synchonrized through mmu_lock (writers) and RCU (writers - * and readers). - */ - struct vhost_map __rcu *maps[VHOST_NUM_ADDRS]; - /* Read by MMU notifier, modified by vring ioctl(), - * synchronized through MMU notifier - * registering/unregistering. - */ - struct vhost_uaddr uaddrs[VHOST_NUM_ADDRS]; -#e...

...*dev; @@ -90,7 +111,21 @@ struct vhost_virtqueue { struct vring_desc __user *desc; struct vring_avail __user *avail; struct vring_used __user *used; + +#if VHOST_ARCH_CAN_ACCEL_UACCESS + /* Read by memory accessors, modified by meta data + * prefetching, MMU notifier and vring ioctl(). + * Synchonrized through mmu_lock. + */ + struct vhost_map *maps[VHOST_NUM_ADDRS]; + /* Read by MMU notifier, modified by vring ioctl(), + * synchronized through MMU notifier + * registering/unregistering. + */ + struct vhost_uaddr uaddrs[VHOST_NUM_ADDRS]; +#endif const struct vhost_umem_node *meta_iotlb[VHO...