similar to: [PATCH V2 0/3] basic busy polling support for vhost_net

On 01/25/2016 03:58 PM, Michael Rapoport wrote: > (restored 'CC, sorry for dropping it originally, Notes is still hard > for me) > > > Jason Wang <jasowang at redhat.com> wrote on 01/25/2016 05:00:05 AM: > > On 01/24/2016 05:00 PM, Mike Rapoport wrote: > > > Hi Jason, > > > > > >> Jason Wang <jasowang <at> redhat.com> writes:

"Michael S. Tsirkin" <mst at redhat.com> wrote on 20/08/2014 01:57:10 PM: > > Results: > > > > Netperf, 1 vm: > > The polling patch improved throughput by ~33% (1516 MB/sec -> 2046 MB/sec). > > Number of exits/sec decreased 6x. > > The same improvement was shown when I tested with 3 vms running netperf > > (4086 MB/sec -> 5545

"Michael S. Tsirkin" <mst at redhat.com> wrote on 20/08/2014 01:57:10 PM: > > Results: > > > > Netperf, 1 vm: > > The polling patch improved throughput by ~33% (1516 MB/sec -> 2046 MB/sec). > > Number of exits/sec decreased 6x. > > The same improvement was shown when I tested with 3 vms running netperf > > (4086 MB/sec -> 5545

"Michael S. Tsirkin" <mst at redhat.com> wrote on 12/08/2014 12:18:50 PM: > From: "Michael S. Tsirkin" <mst at redhat.com> > To: David Miller <davem at davemloft.net> > Cc: Razya Ladelsky/Haifa/IBM at IBMIL, kvm at vger.kernel.org, Alex > Glikson/Haifa/IBM at IBMIL, Eran Raichstein/Haifa/IBM at IBMIL, Yossi > Kuperman1/Haifa/IBM at IBMIL,

"Michael S. Tsirkin" <mst at redhat.com> wrote on 12/08/2014 12:18:50 PM: > From: "Michael S. Tsirkin" <mst at redhat.com> > To: David Miller <davem at davemloft.net> > Cc: Razya Ladelsky/Haifa/IBM at IBMIL, kvm at vger.kernel.org, Alex > Glikson/Haifa/IBM at IBMIL, Eran Raichstein/Haifa/IBM at IBMIL, Yossi > Kuperman1/Haifa/IBM at IBMIL,

This series tries to add basic busy polling for vhost net. The idea is simple: at the end of tx/rx processing, busy polling for new tx added descriptor and rx receive socket for a while. The maximum number of time (in us) could be spent on busy polling was specified ioctl. Test A were done through: - 50 us as busy loop timeout - Netperf 2.6 - Two machines with back to back connected mlx4 - Guest

This series tries to add basic busy polling for vhost net. The idea is simple: at the end of tx/rx processing, busy polling for new tx added descriptor and rx receive socket for a while. The maximum number of time (in us) could be spent on busy polling was specified ioctl. Test A were done through: - 50 us as busy loop timeout - Netperf 2.6 - Two machines with back to back connected mlx4 - Guest

> > > > Hi Michael, > > > > Sorry for the delay, had some problems with my mailbox, and I realized > > just now that > > my reply wasn't sent. > > The vm indeed ALWAYS utilized 100% cpu, whether polling was enabled or > > not. > > The vhost thread utilized less than 100% (of the other cpu) when polling > > was disabled. >

> > > > Hi Michael, > > > > Sorry for the delay, had some problems with my mailbox, and I realized > > just now that > > my reply wasn't sent. > > The vm indeed ALWAYS utilized 100% cpu, whether polling was enabled or > > not. > > The vhost thread utilized less than 100% (of the other cpu) when polling > > was disabled. >

From: "Michael S. Tsirkin" <mst at redhat.com> Date: Sun, 10 Aug 2014 21:45:59 +0200 > On Sun, Aug 10, 2014 at 11:30:35AM +0300, Razya Ladelsky wrote: ... > And, did your tests actually produce 100% load on both host CPUs? ... Michael, please do not quote an entire patch just to ask a one line question. I truly, truly, wish it was simpler in modern email clients to

From: "Michael S. Tsirkin" <mst at redhat.com> Date: Sun, 10 Aug 2014 21:45:59 +0200 > On Sun, Aug 10, 2014 at 11:30:35AM +0300, Razya Ladelsky wrote: ... > And, did your tests actually produce 100% load on both host CPUs? ... Michael, please do not quote an entire patch just to ask a one line question. I truly, truly, wish it was simpler in modern email clients to

> That was just one example. There many other possibilities. Either > actually make the systems load all host CPUs equally, or divide > throughput by host CPU. > The polling patch adds this capability to vhost, reducing costly exit overhead when the vm is loaded. In order to load the vm I ran netperf with msg size of 256: Without polling: 2480 Mbits/sec, utilization: vm - 100%

> That was just one example. There many other possibilities. Either > actually make the systems load all host CPUs equally, or divide > throughput by host CPU. > The polling patch adds this capability to vhost, reducing costly exit overhead when the vm is loaded. In order to load the vm I ran netperf with msg size of 256: Without polling: 2480 Mbits/sec, utilization: vm - 100%

On Fri, Feb 26, 2016 at 04:42:44PM +0800, Jason Wang wrote: > This patch tries to poll for new added tx buffer or socket receive > queue for a while at the end of tx/rx processing. The maximum time > spent on polling were specified through a new kind of vring ioctl. > > Signed-off-by: Jason Wang <jasowang at redhat.com> Looks good overall, but I still see one problem. >

On Fri, Feb 26, 2016 at 04:42:44PM +0800, Jason Wang wrote: > This patch tries to poll for new added tx buffer or socket receive > queue for a while at the end of tx/rx processing. The maximum time > spent on polling were specified through a new kind of vring ioctl. > > Signed-off-by: Jason Wang <jasowang at redhat.com> Looks good overall, but I still see one problem. >

From: Razya Ladelsky <razya at il.ibm.com> Date: Thu, 31 Jul 2014 09:47:20 +0300 Subject: [PATCH] vhost: Add polling mode When vhost is waiting for buffers from the guest driver (e.g., more packets to send in vhost-net's transmit queue), it normally goes to sleep and waits for the guest to "kick" it. This kick involves a PIO in the guest, and therefore an exit (and possibly

From: Razya Ladelsky <razya at il.ibm.com> Date: Thu, 31 Jul 2014 09:47:20 +0300 Subject: [PATCH] vhost: Add polling mode When vhost is waiting for buffers from the guest driver (e.g., more packets to send in vhost-net's transmit queue), it normally goes to sleep and waits for the guest to "kick" it. This kick involves a PIO in the guest, and therefore an exit (and possibly

On 02/26/2016 09:42 AM, Jason Wang wrote: > This patch tries to poll for new added tx buffer or socket receive > queue for a while at the end of tx/rx processing. The maximum time > spent on polling were specified through a new kind of vring ioctl. > > Signed-off-by: Jason Wang <jasowang at redhat.com> > --- > drivers/vhost/net.c | 79

On 02/26/2016 09:42 AM, Jason Wang wrote: > This patch tries to poll for new added tx buffer or socket receive > queue for a while at the end of tx/rx processing. The maximum time > spent on polling were specified through a new kind of vring ioctl. > > Signed-off-by: Jason Wang <jasowang at redhat.com> > --- > drivers/vhost/net.c | 79

On 02/28/2016 10:09 PM, Michael S. Tsirkin wrote: > On Fri, Feb 26, 2016 at 04:42:44PM +0800, Jason Wang wrote: >> > This patch tries to poll for new added tx buffer or socket receive >> > queue for a while at the end of tx/rx processing. The maximum time >> > spent on polling were specified through a new kind of vring ioctl. >> > >> >