search for: vhost_goodcopy_len

On Mon, Sep 02, 2013 at 04:40:59PM +0800, Jason Wang wrote: > Currently, even if the packet length is smaller than VHOST_GOODCOPY_LEN, if > upend_idx != done_idx we still set zcopy_used to true and rollback this choice > later. This could be avoided by determining zerocopy once by checking all > conditions at one time before. > > Signed-off-by: Jason Wang <jasowang at redhat.com> > --- > drivers/vhost...

On Mon, Sep 02, 2013 at 04:40:59PM +0800, Jason Wang wrote: > Currently, even if the packet length is smaller than VHOST_GOODCOPY_LEN, if > upend_idx != done_idx we still set zcopy_used to true and rollback this choice > later. This could be avoided by determining zerocopy once by checking all > conditions at one time before. > > Signed-off-by: Jason Wang <jasowang at redhat.com> > --- > drivers/vhost...

On Thu, Sep 05, 2013 at 10:54:44AM +0800, Jason Wang wrote: > On 09/04/2013 07:59 PM, Michael S. Tsirkin wrote: > > On Mon, Sep 02, 2013 at 04:40:59PM +0800, Jason Wang wrote: > >> Currently, even if the packet length is smaller than VHOST_GOODCOPY_LEN, if > >> upend_idx != done_idx we still set zcopy_used to true and rollback this choice > >> later. This could be avoided by determining zerocopy once by checking all > >> conditions at one time before. > >> > >> Signed-off-by: Jason Wang <jasowang at...

On Thu, Sep 05, 2013 at 10:54:44AM +0800, Jason Wang wrote: > On 09/04/2013 07:59 PM, Michael S. Tsirkin wrote: > > On Mon, Sep 02, 2013 at 04:40:59PM +0800, Jason Wang wrote: > >> Currently, even if the packet length is smaller than VHOST_GOODCOPY_LEN, if > >> upend_idx != done_idx we still set zcopy_used to true and rollback this choice > >> later. This could be avoided by determining zerocopy once by checking all > >> conditions at one time before. > >> > >> Signed-off-by: Jason Wang <jasowang at...

Hello. On 08/30/2013 08:29 AM, Jason Wang wrote: > Currently, even if the packet length is smaller than VHOST_GOODCOPY_LEN, if > upend_idx != done_idx we still set zcopy_used to true and rollback this choice > later. This could be avoided by determine zerocopy once by checking all > conditions at one time before. > Signed-off-by: Jason Wang <jasowang at redhat.com> > --- > drivers/vhost/net.c...

Hello. On 08/30/2013 08:29 AM, Jason Wang wrote: > Currently, even if the packet length is smaller than VHOST_GOODCOPY_LEN, if > upend_idx != done_idx we still set zcopy_used to true and rollback this choice > later. This could be avoided by determine zerocopy once by checking all > conditions at one time before. > Signed-off-by: Jason Wang <jasowang at redhat.com> > --- > drivers/vhost/net.c...

Currently, even if the packet length is smaller than VHOST_GOODCOPY_LEN, if upend_idx != done_idx we still set zcopy_used to true and rollback this choice later. This could be avoided by determine zerocopy once by checking all conditions at one time before. Signed-off-by: Jason Wang <jasowang at redhat.com> --- drivers/vhost/net.c | 46 +++++++++++++++++++----...

Currently, even if the packet length is smaller than VHOST_GOODCOPY_LEN, if upend_idx != done_idx we still set zcopy_used to true and rollback this choice later. This could be avoided by determining zerocopy once by checking all conditions at one time before. Signed-off-by: Jason Wang <jasowang at redhat.com> --- drivers/vhost/net.c | 47 ++++++++++++++++++++-...

On 09/04/2013 07:59 PM, Michael S. Tsirkin wrote: > On Mon, Sep 02, 2013 at 04:40:59PM +0800, Jason Wang wrote: >> Currently, even if the packet length is smaller than VHOST_GOODCOPY_LEN, if >> upend_idx != done_idx we still set zcopy_used to true and rollback this choice >> later. This could be avoided by determining zerocopy once by checking all >> conditions at one time before. >> >> Signed-off-by: Jason Wang <jasowang at redhat.com> >>...

This series tries to unify and simplify vhost codes especially for zerocopy. With this series, 5% - 10% improvement for per cpu throughput were seen during netperf guest sending test. Plase review. Changes from V2: - Typo fixes and code style fix - Add performance gain in the commit log of patch 2/6 - Retest the update the result in patch 6/6 Changes from V1: - Fix the zerocopy enabling check

This series tries to unify and simplify vhost codes especially for zerocopy. With this series, 5% - 10% improvement for per cpu throughput were seen during netperf guest sending test. Plase review. Changes from V2: - Typo fixes and code style fix - Add performance gain in the commit log of patch 2/6 - Retest the update the result in patch 6/6 Changes from V1: - Fix the zerocopy enabling check

...te: > On Thu, Sep 05, 2013 at 10:54:44AM +0800, Jason Wang wrote: >> > On 09/04/2013 07:59 PM, Michael S. Tsirkin wrote: >>> > > On Mon, Sep 02, 2013 at 04:40:59PM +0800, Jason Wang wrote: >>>> > >> Currently, even if the packet length is smaller than VHOST_GOODCOPY_LEN, if >>>> > >> upend_idx != done_idx we still set zcopy_used to true and rollback this choice >>>> > >> later. This could be avoided by determining zerocopy once by checking all >>>> > >> conditions at one time before. >>>> &...

...the number of zerocopy skbs in flight. When reached, transmission stalls. Stalls cause latency, as well as head-of-line blocking of other flows that do not use zerocopy. Instead of stalling, revert to copy-based transmission. Tested by sending two udp flows from guest to host, one with payload of VHOST_GOODCOPY_LEN, the other too small for zerocopy (1B). The large flow is redirected to a netem instance with 1MBps rate limit and deep 1000 entry queue. modprobe ifb ip link set dev ifb0 up tc qdisc add dev ifb0 root netem limit 1000 rate 1MBit tc qdisc add dev tap0 ingress tc filter add dev tap0 pare...

...the number of zerocopy skbs in flight. When reached, transmission stalls. Stalls cause latency, as well as head-of-line blocking of other flows that do not use zerocopy. Instead of stalling, revert to copy-based transmission. Tested by sending two udp flows from guest to host, one with payload of VHOST_GOODCOPY_LEN, the other too small for zerocopy (1B). The large flow is redirected to a netem instance with 1MBps rate limit and deep 1000 entry queue. modprobe ifb ip link set dev ifb0 up tc qdisc add dev ifb0 root netem limit 1000 rate 1MBit tc qdisc add dev tap0 ingress tc filter add dev tap0 pare...

Hi all: This series tries to unify and simplify vhost codes especially for zerocopy. With this series, 5% - 10% improvement for per cpu throughput were seen during netperf guest sending test. Plase review. Changes from V1: - Fix the zerocopy enabling check by changing the check of upend_idx != done_idx to (upend_idx + 1) % UIO_MAXIOV == done_idx. - Switch to use put_user() in

Hi all: This series tries to unify and simplify vhost codes especially for zerocopy. With this series, 5% - 10% improvement for per cpu throughput were seen during netperf guest sending test. Plase review. Changes from V1: - Fix the zerocopy enabling check by changing the check of upend_idx != done_idx to (upend_idx + 1) % UIO_MAXIOV == done_idx. - Switch to use put_user() in

Hi all: This series tries to unify and simplify vhost codes especially for zerocopy. Plase review. Thanks Jason Wang (6): vhost_net: make vhost_zerocopy_signal_used() returns void vhost_net: use vhost_add_used_and_signal_n() in vhost_zerocopy_signal_used() vhost: switch to use vhost_add_used_n() vhost_net: determine whether or not to use zerocopy at one time vhost_net: poll vhost

Hi all: This series tries to unify and simplify vhost codes especially for zerocopy. Plase review. Thanks Jason Wang (6): vhost_net: make vhost_zerocopy_signal_used() returns void vhost_net: use vhost_add_used_and_signal_n() in vhost_zerocopy_signal_used() vhost: switch to use vhost_add_used_n() vhost_net: determine whether or not to use zerocopy at one time vhost_net: poll vhost

...the number of zerocopy skbs in flight. When reached, transmission stalls. Stalls cause latency, as well as head-of-line blocking of other flows that do not use zerocopy. Instead of stalling, revert to copy-based transmission. Tested by sending two udp flows from guest to host, one with payload of VHOST_GOODCOPY_LEN, the other too small for zerocopy (1B). The large flow is redirected to a netem instance with 1MBps rate limit and deep 1000 entry queue. modprobe ifb ip link set dev ifb0 up tc qdisc add dev ifb0 root netem limit 1000 rate 1MBit tc qdisc add dev tap0 ingress tc filter add dev tap0 pare...

...the number of zerocopy skbs in flight. When reached, transmission stalls. Stalls cause latency, as well as head-of-line blocking of other flows that do not use zerocopy. Instead of stalling, revert to copy-based transmission. Tested by sending two udp flows from guest to host, one with payload of VHOST_GOODCOPY_LEN, the other too small for zerocopy (1B). The large flow is redirected to a netem instance with 1MBps rate limit and deep 1000 entry queue. modprobe ifb ip link set dev ifb0 up tc qdisc add dev ifb0 root netem limit 1000 rate 1MBit tc qdisc add dev tap0 ingress tc filter add dev tap0 pare...