similar to: [PATCH] virtio/ringtest: virtio_ring: fix up need_event math

last kicked event index must be updated unconditionally: even if we don't need to kick, we do not want to re-check the same entry for events. Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- tools/virtio/ringtest/ring.c | 24 +++++++++++++++--------- 1 file changed, 15 insertions(+), 9 deletions(-) diff --git a/tools/virtio/ringtest/ring.c b/tools/virtio/ringtest/ring.c index

last kicked event index must be updated unconditionally: even if we don't need to kick, we do not want to re-check the same entry for events. Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- tools/virtio/ringtest/ring.c | 24 +++++++++++++++--------- 1 file changed, 15 insertions(+), 9 deletions(-) diff --git a/tools/virtio/ringtest/ring.c b/tools/virtio/ringtest/ring.c index

last kicked event index must be updated unconditionally: even if we don't need to kick, we do not want to re-check the same entry for events. Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- Changes from v1: fix inverted logic in call_used tools/virtio/ringtest/ring.c | 24 +++++++++++++++--------- 1 file changed, 15 insertions(+), 9 deletions(-) diff --git

last kicked event index must be updated unconditionally: even if we don't need to kick, we do not want to re-check the same entry for events. Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- Changes from v1: fix inverted logic in call_used tools/virtio/ringtest/ring.c | 24 +++++++++++++++--------- 1 file changed, 15 insertions(+), 9 deletions(-) diff --git

This adds micro-benchmarks useful for tuning virtio ring layouts. Three layouts are currently implemented: - virtio 0.9 compatible one - an experimental extension bypassing the ring index, polling ring itself instead - an experimental extension bypassing avail and used ring completely Typical use: sh run-on-all.sh perf stat -r 10 --log-fd 1 -- ./ring It doesn't depend on the kernel

This adds micro-benchmarks useful for tuning virtio ring layouts. Three layouts are currently implemented: - virtio 0.9 compatible one - an experimental extension bypassing the ring index, polling ring itself instead - an experimental extension bypassing avail and used ring completely Typical use: sh run-on-all.sh perf stat -r 10 --log-fd 1 -- ./ring It doesn't depend on the kernel

On Thu, 26 Oct 2017 04:48:01 +0300 "Michael S. Tsirkin" <mst at redhat.com> wrote: > last kicked event index must be updated unconditionally: > even if we don't need to kick, we do not want to re-check > the same entry for events. > > Signed-off-by: Michael S. Tsirkin <mst at redhat.com> > --- > tools/virtio/ringtest/ring.c | 24

skips ring accesses but drops out of order support At high level this follows alf design https://github.com/netoptimizer/prototype-kernel/blob/master/kernel/lib/alf_queue.c but on most (single-threaded) benchmarks this seems to be slower than the layout without index use. Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- tools/virtio/ringtest/virtio_ring_0_9.c | 49

skips ring accesses but drops out of order support At high level this follows alf design https://github.com/netoptimizer/prototype-kernel/blob/master/kernel/lib/alf_queue.c but on most (single-threaded) benchmarks this seems to be slower than the layout without index use. Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- tools/virtio/ringtest/virtio_ring_0_9.c | 49

These are used for legacy ring format, switch to APIs that make this explicit. Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- tools/virtio/ringtest/virtio_ring_0_9.c | 6 +++--- tools/virtio/virtio_test.c | 6 +++--- tools/virtio/vringh_test.c | 18 +++++++++--------- 3 files changed, 15 insertions(+), 15 deletions(-) diff --git

These are used for legacy ring format, switch to APIs that make this explicit. Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- tools/virtio/ringtest/virtio_ring_0_9.c | 6 +++--- tools/virtio/virtio_test.c | 6 +++--- tools/virtio/vringh_test.c | 18 +++++++++--------- 3 files changed, 15 insertions(+), 15 deletions(-) diff --git

These are used for legacy ring format, switch to APIs that make this explicit. Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- tools/virtio/ringtest/virtio_ring_0_9.c | 6 +++--- tools/virtio/virtio_test.c | 6 +++--- tools/virtio/vringh_test.c | 18 +++++++++--------- 3 files changed, 15 insertions(+), 15 deletions(-) diff --git

These are used for legacy ring format, switch to APIs that make this explicit. Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- tools/virtio/ringtest/virtio_ring_0_9.c | 6 +++--- tools/virtio/virtio_test.c | 6 +++--- tools/virtio/vringh_test.c | 18 +++++++++--------- 3 files changed, 15 insertions(+), 15 deletions(-) diff --git

These are used for legacy ring format, switch to APIs that make this explicit. Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- tools/virtio/ringtest/virtio_ring_0_9.c | 6 +++--- tools/virtio/virtio_test.c | 6 +++--- tools/virtio/vringh_test.c | 18 +++++++++--------- 3 files changed, 15 insertions(+), 15 deletions(-) diff --git

These are used for legacy ring format, switch to APIs that make this explicit. Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- tools/virtio/ringtest/virtio_ring_0_9.c | 6 +++--- tools/virtio/virtio_test.c | 6 +++--- tools/virtio/vringh_test.c | 18 +++++++++--------- 3 files changed, 15 insertions(+), 15 deletions(-) diff --git

struct vring (in the uapi directory) and supporting APIs are kept around to solely avoid breaking old userspace builds. It's not actually part of the UAPI - it was kept in the UAPI header by mistake, and using it in kernel isn't necessary and prevents us from making changes safely. In particular, the APIs actually assume the legacy layout. Add an internal kernel-only struct vring, add

struct vring (in the uapi directory) and supporting APIs are kept around to avoid breaking old userspace builds. It's not actually part of the UAPI - it was kept in the UAPI header by mistake, and using it in kernel isn't necessary and prevents us from making changes safely. In particular, the APIs actually assume the legacy layout. Add struct vring_s (identical ATM) and supporting legacy

struct vring (in the uapi directory) and supporting APIs are kept around to avoid breaking old userspace builds. It's not actually part of the UAPI - it was kept in the UAPI header by mistake, and using it in kernel isn't necessary and prevents us from making changes safely. In particular, the APIs actually assume the legacy layout. Add struct vring_s (identical ATM) and supporting legacy

The following changes since commit d8a5b80568a9cb66810e75b182018e9edb68e8ff: Linux 4.15 (2018-01-28 13:20:33 -0800) are available in the Git repository at: git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost.git tags/for_linus for you to fetch changes up to d25cc43c6775bff6b8e3dad97c747954b805e421: vhost: don't hold onto file pointer for VHOST_SET_LOG_FD (2018-02-01 16:26:47

Add ringtest based unit test for ptr ring. Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- tools/virtio/ringtest/ptr_ring.c | 192 +++++++++++++++++++++++++++++++++++++++ tools/virtio/ringtest/Makefile | 5 +- 2 files changed, 196 insertions(+), 1 deletion(-) create mode 100644 tools/virtio/ringtest/ptr_ring.c diff --git a/tools/virtio/ringtest/ptr_ring.c