search for: busyloops

On 2018?06?30? 00:38, Michael S. Tsirkin wrote: > On Fri, Jun 29, 2018 at 05:09:50PM +0900, Toshiaki Makita wrote: >> Under heavy load vhost busypoll may run without suppressing >> notification. For example tx zerocopy callback can push tx work while >> handle_tx() is running, then busyloop exits due to vhost_has_work() >> condition and enables notification but

On 2018?06?30? 00:38, Michael S. Tsirkin wrote: > On Fri, Jun 29, 2018 at 05:09:50PM +0900, Toshiaki Makita wrote: >> Under heavy load vhost busypoll may run without suppressing >> notification. For example tx zerocopy callback can push tx work while >> handle_tx() is running, then busyloop exits due to vhost_has_work() >> condition and enables notification but

Under heavy load vhost busypoll may run without suppressing notification. For example tx zerocopy callback can push tx work while handle_tx() is running, then busyloop exits due to vhost_has_work() condition and enables notification but immediately reenters handle_tx() because the pushed work was tx. In this case handle_tx() tries to disable notification again, but when using event_idx it by

Under heavy load vhost busypoll may run without suppressing notification. For example tx zerocopy callback can push tx work while handle_tx() is running, then busyloop exits due to vhost_has_work() condition and enables notification but immediately reenters handle_tx() because the pushed work was tx. In this case handle_tx() tries to disable notification again, but when using event_idx it by

Under heavy load vhost busypoll may run without suppressing notification. For example tx zerocopy callback can push tx work while handle_tx() is running, then busyloop exits due to vhost_has_work() condition and enables notification but immediately reenters handle_tx() because the pushed work was tx. In this case handle_tx() tries to disable notification again, but when using event_idx it by

Under heavy load vhost tx busypoll tend not to suppress vq kicks, which causes poor guest tx performance. The detailed scenario is described in commitlog of patch 2. Rx seems not to have that serious problem, but for consistency I made a similar change on rx to avoid rx wakeups (patch 3). Additionary patch 4 is to avoid rx kicks under heavy load during busypoll. Tx performance is greatly improved

On 2018?06?26? 13:17, xiangxia.m.yue at gmail.com wrote: > From: Tonghao Zhang <xiangxia.m.yue at gmail.com> > > This patch improves the guest receive performance from > host. On the handle_tx side, we poll the sock receive > queue at the same time. handle_rx do that in the same way. > > For avoiding deadlock, change the code to lock the vq one > by one and use the

On 2018/07/02 11:41, Jason Wang wrote: > On 2018?06?30? 00:38, Michael S. Tsirkin wrote: >> On Fri, Jun 29, 2018 at 05:09:50PM +0900, Toshiaki Makita wrote: >>> Under heavy load vhost busypoll may run without suppressing >>> notification. For example tx zerocopy callback can push tx work while >>> handle_tx() is running, then busyloop exits due to

We may run out of avail rx ring descriptor under heavy load but busypoll did not detect it so busypoll may have exited prematurely. Avoid this by checking rx ring full during busypoll. Signed-off-by: Toshiaki Makita <makita.toshiaki at lab.ntt.co.jp> --- drivers/vhost/net.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/drivers/vhost/net.c

On 2018?07?04? 12:31, xiangxia.m.yue at gmail.com wrote: > 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. > > v4 -> v5: > fix some

On 2018?07?11? 11:49, Tonghao Zhang wrote: > On Wed, Jul 11, 2018 at 10:56 AM Jason Wang <jasowang at redhat.com> wrote: >> >> >> On 2018?07?04? 12:31, xiangxia.m.yue at gmail.com wrote: >>> From: Tonghao Zhang <xiangxia.m.yue at gmail.com> >>> >>> This patches improve the guest receive and transmit performance. >>> On the

On 2018?07?11? 19:59, Michael S. Tsirkin wrote: > On Wed, Jul 11, 2018 at 01:12:59PM +0800, Jason Wang wrote: >> >> On 2018?07?11? 11:49, Tonghao Zhang wrote: >>> On Wed, Jul 11, 2018 at 10:56 AM Jason Wang <jasowang at redhat.com> wrote: >>>> >>>> On 2018?07?04? 12:31, xiangxia.m.yue at gmail.com wrote: >>>>> From: Tonghao Zhang

On Sun, Sep 9, 2018 at 7:52 PM <xiangxia.m.yue at gmail.com> wrote: > > From: Tonghao Zhang <xiangxia.m.yue at gmail.com> > > This patches improve the guest receive 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, 5, 6 > > Tonghao Zhang

On 2018?09?23? 21:48, Tonghao Zhang wrote: > On Sun, Sep 9, 2018 at 7:52 PM <xiangxia.m.yue at gmail.com> wrote: >> From: Tonghao Zhang <xiangxia.m.yue at gmail.com> >> >> This patches improve the guest receive performance. >> On the handle_tx side, we poll the sock receive queue >> at the same time. handle_rx do that in the same way. >> >>

SunOS pop01.unix 5.10 Generic_118844-26 i86pc i386 i86pc dovecot-1.0.beta3 Dovecot itself runs well, and was easy to confirgure with LDAP. However, I am seeing a cpu busy-loop in dovecot-auth. Is this a known issue, or do you know why it happens? If needed I can go deeper if so required. PID USERNAME LWP PRI NICE SIZE RES STATE TIME CPU COMMAND 26440 root 1 10 0 4232K

On 2018/07/03 18:05, Jason Wang wrote: > On 2018?07?03? 15:31, Toshiaki Makita wrote: >> We may run out of avail rx ring descriptor under heavy load but busypoll >> did not detect it so busypoll may have exited prematurely. Avoid this by >> checking rx ring full during busypoll. > > Actually, we're checking whether it was empty in fact? My understanding is that on

On 2018?07?12? 11:34, Michael S. Tsirkin wrote: > On Thu, Jul 12, 2018 at 11:26:12AM +0800, Jason Wang wrote: >> >> On 2018?07?11? 19:59, Michael S. Tsirkin wrote: >>> On Wed, Jul 11, 2018 at 01:12:59PM +0800, Jason Wang wrote: >>>> On 2018?07?11? 11:49, Tonghao Zhang wrote: >>>>> On Wed, Jul 11, 2018 at 10:56 AM Jason Wang <jasowang at

On 2018?06?29? 16:09, Toshiaki Makita wrote: > Under heavy load vhost busypoll may run without suppressing > notification. For example tx zerocopy callback can push tx work while > handle_tx() is running, then busyloop exits due to vhost_has_work() > condition and enables notification but immediately reenters handle_tx() > because the pushed work was tx. In this case handle_tx()

On Fri, Jun 29, 2018 at 05:09:50PM +0900, Toshiaki Makita wrote: > Under heavy load vhost busypoll may run without suppressing > notification. For example tx zerocopy callback can push tx work while > handle_tx() is running, then busyloop exits due to vhost_has_work() > condition and enables notification but immediately reenters handle_tx() > because the pushed work was tx. In this

http://bugs.freedesktop.org/show_bug.cgi?id=15845 Summary: X busyloops when huge image in firefox Product: xorg Version: git Platform: x86-64 (AMD64) OS/Version: Linux (All) Status: NEW Severity: normal Priority: medium Component: Driver/nouveau AssignedTo: nouveau at lists.freede...