From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jintack Lim Subject: Re: [Xen-users] Changing netback tx interrupts affinity on Dom0 Date: Thu, 3 Sep 2015 12:06:39 -0400 Message-ID: References: <1441294496.26292.372.camel@citrix.com> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============7807817701501625273==" Return-path: In-Reply-To: <1441294496.26292.372.camel@citrix.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: xen-devel Cc: Ian Campbell List-Id: xen-devel@lists.xenproject.org --===============7807817701501625273== Content-Type: multipart/alternative; boundary=001a1130c356e971c4051ed9f745 --001a1130c356e971c4051ed9f745 Content-Type: text/plain; charset=UTF-8 Hi, I was trying to set irq affinity by writing a value to /proc/irq//smp_affinity, but smp_affinity value was not changed at all. Ian suggested to take this to the devel list. I'm working on Xen4.5, ARMv8. Thanks, Jintack On Thu, Sep 3, 2015 at 11:34 AM, Ian Campbell wrote: > On Thu, 2015-09-03 at 10:59 -0400, Jintack Lim wrote: > > Hi, > > > > While I was running Apache server, > > I found that one of Dom0 vcpu is running 100% to handle irqs, > > and those irqs are set to be processed only on that specific vcpu. > > > > Referring to this document, > > http://wiki.xen.org/wiki/Network_Throughput_and_Performance_Guide > > I tried to change smp_affinity by writing a value to /proc/irq/ > -no>/smp_affinity, > > however the smp_affinity value was not changed. > > > > I'm working on Xen 4.5 on ARMv8, > > and the irq is netback tx interrupt. > > > > # cat /proc/irq/106/smp_affinity > > 1 > > > > # cat /proc/interrupts > > ... > > 106: 53849 0 0 0 xen-dyn-event > > vif1.1-q0-tx > > 107: 1 0 0 0 xen-dyn-event > > vif1.1-q0-rx > > 108: 61460 0 0 0 xen-dyn-event > > vif1.1-q1-tx > > 109: 1 0 0 0 xen-dyn-event > > vif1.1-q1-rx > > 110: 67118 0 0 0 xen-dyn-event > > vif1.1-q2-tx > > 111: 1 0 0 0 xen-dyn-event > > vif1.1-q2-rx > > 112: 58273 0 0 0 xen-dyn-event > > vif1.1-q3-tx > > 113: 1 0 0 0 xen-dyn-event > > vif1.1-q3-rx > > ... > > > > What would be the way to change smp_affinity? > > It should be via /proc/irq//smp_affinity as you've tried, I asked > Stefano and he things this was already implemented in 4.5 even. That it is > not happening would be a bug, I think. > > I'd suggest you take this to the devel list as a bug. > > > and where is the affinity set initially for netback tx interrupts? > > Not, sure, I think it might just be generic IRQ code. > > Ian. > > --001a1130c356e971c4051ed9f745 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable
Hi,

I was trying to set irq affinity by= writing a value to=C2=A0/proc/irq/<irq>/smp_affinity,
but = smp_affinity value was not changed at all.
Ian suggested to take = this to the devel list.
I'm working on Xen4.5, ARMv8.

Thanks,
Jintack

On Thu, Sep 3, 2015 at 11:34 AM, Ian Campbe= ll <ian.campbell@citrix= .com> wrote:
On Thu, 2015-09-03 at 10:59 -0400, Jintack Lim wrote:
> Hi,
>
> While I was running Apache server,
> I found that one of Dom0 vcpu is running 100% to handle irqs,
> and those irqs are set to be processed only on that specific vcpu.
>
> Referring to this document,
> http://wiki.xen.org/wiki/Netwo= rk_Throughput_and_Performance_Guide
> I tried to change smp_affinity by writing a value to /proc/irq/<irq=
> -no>/smp_affinity,
> however the smp_affinity value was not changed.
>
> I'm working on Xen 4.5 on ARMv8,
> and the irq is netback tx interrupt.
>
> # cat /proc/irq/106/smp_affinity
> 1
>
> # cat /proc/interrupts
> ...
> 106:=C2=A0 =C2=A0 =C2=A0 53849=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 0=C2= =A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 0=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 0=C2=A0= =C2=A0xen-dyn-event
> vif1.1-q0-tx
> 107:=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 1=C2=A0 =C2=A0 =C2=A0 =C2=A0 = =C2=A0 0=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 0=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2= =A0 0=C2=A0 =C2=A0xen-dyn-event
> vif1.1-q0-rx
> 108:=C2=A0 =C2=A0 =C2=A0 61460=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 0=C2= =A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 0=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 0=C2=A0= =C2=A0xen-dyn-event
> vif1.1-q1-tx
> 109:=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 1=C2=A0 =C2=A0 =C2=A0 =C2=A0 = =C2=A0 0=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 0=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2= =A0 0=C2=A0 =C2=A0xen-dyn-event
> vif1.1-q1-rx
> 110:=C2=A0 =C2=A0 =C2=A0 67118=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 0=C2= =A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 0=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 0=C2=A0= =C2=A0xen-dyn-event
> vif1.1-q2-tx
> 111:=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 1=C2=A0 =C2=A0 =C2=A0 =C2=A0 = =C2=A0 0=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 0=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2= =A0 0=C2=A0 =C2=A0xen-dyn-event
> vif1.1-q2-rx
> 112:=C2=A0 =C2=A0 =C2=A0 58273=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 0=C2= =A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 0=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 0=C2=A0= =C2=A0xen-dyn-event
> vif1.1-q3-tx
> 113:=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 1=C2=A0 =C2=A0 =C2=A0 =C2=A0 = =C2=A0 0=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 0=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2= =A0 0=C2=A0 =C2=A0xen-dyn-event
> vif1.1-q3-rx
> ...
>
> What would be the way to change smp_affinity?

It should be via /proc/irq/<irq>/smp_affinity as you'= ve tried, I asked
Stefano and he things this was already implemented in 4.5 even. That it is<= br> not happening would be a bug, I think.

I'd suggest you take this to the devel list as a bug.

> and where is the affinity set initially for netback tx interrupts?

Not, sure, I think it might just be generic IRQ code.

Ian.


--001a1130c356e971c4051ed9f745-- --===============7807817701501625273== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel --===============7807817701501625273==--