Re: [PATCH][RT] netpoll: Always take poll_lock when doing polling

I asked on 2016-06-07 17:19:43 [-0700]: >>cpsw_rx_poll() is called even when there is essentially no network >>traffic, so I'm not sure how to tell if NAPI is working as intended. On Thu, Jun 9, 2016 at 5:37 AM, Sebastian Andrzej Siewior wrote: > You should see an

Re: [PATCH][RT] netpoll: Always take poll_lock when doing polling

On Fri, 10 Jun 2016 18:20:22 +0200 Sebastian Andrzej Siewior wrote: > > We actually triggered a starvation due to this. I was just seeing if > > Alison hit the same issue we did in our tests. > > Okay. Didn't get this information from him. But this is only because > the

Re: [PATCH][RT] netpoll: Always take poll_lock when doing polling

On Fri, 2016-06-10 at 17:30 +0200, Sebastian Andrzej Siewior wrote: > * Steven Rostedt | 2016-05-26 19:56:41 [-0400]: > > >For example: > > > > > > > > napi_schedule_prep() > >test_and_set_bit(NAPI_STATE_SCHED, >state) > > > > > > > > sk_busy_loop() > > > > do { > >

Re: [PATCH][RT] netpoll: Always take poll_lock when doing polling

On 06/10/2016 06:11 PM, Steven Rostedt wrote: >> It is true that in RT we don't have such a limit like in !RT. You would >> need to use __raise_softirq_irqoff_ksoft() instead the normal or + >> wakeup() since you may have timers pending and those need to go to the >> "other" ksoftirqd. >> But then

Re: [PATCH][RT] netpoll: Always take poll_lock when doing polling

On Fri, 10 Jun 2016 17:57:17 +0200 Sebastian Andrzej Siewior wrote: > * Steven Rostedt | 2016-06-04 07:11:31 [-0400]: > > >From: Steven Rostedt > >Date: Tue, 5 Jan 2016 14:53:09 -0500 > >Subject: [PATCH] softirq: Perform softirqs in local_bh_enable()

Re: [PATCH][RT] netpoll: Always take poll_lock when doing polling

* Steven Rostedt | 2016-06-04 07:11:31 [-0400]: >From: Steven Rostedt >Date: Tue, 5 Jan 2016 14:53:09 -0500 >Subject: [PATCH] softirq: Perform softirqs in local_bh_enable() for a limited > amount of time > >To prevent starvation of tasks like ksoftirqd, if the task that is

Re: [PATCH][RT] netpoll: Always take poll_lock when doing polling

* Steven Rostedt | 2016-05-26 19:56:41 [-0400]: >For example: > > > > napi_schedule_prep() >test_and_set_bit(NAPI_STATE_SCHED, >state) > > > > sk_busy_loop() > > do { > rc = busy_poll() > ret = napi_schedule_prep() >return

Re: [PATCH][RT] netpoll: Always take poll_lock when doing polling

* Alison Chaiken | 2016-06-07 17:19:43 [-0700]: >Sorry to be obscure; I had applied that patch to v4.1.6-rt5. Using the latest is often not a bad choice compared to the random tree you have here. >> What I remember from testing the two patches on am335x was that before a >> ping flood on gbit

Re: [PATCH][RT] netpoll: Always take poll_lock when doing polling

I wrote: >>We've applied Sebastian's commit "softirq: split timer softirqs out of >>ksoftirqd," which improved event loop stability substantially when we Sebastian Andrzej Siewior replied: >Why did you apply that one? You have 4.1.18-ti-rt so I don't know how >that works

Re: [PATCH][RT] netpoll: Always take poll_lock when doing polling

* Alison Chaiken | 2016-06-05 08:16:58 [-0700]: >I did try that patch, but it hasn't made much difference. Let me >back up and restate the problem I'm trying to solve, which is that a >DRA7X OMAP5 SOC system running a patched 4.1.18-ti-rt kernel has a >main event loop in user space that misses

Re: [PATCH][RT] netpoll: Always take poll_lock when doing polling

Steven Rostedt suggests in reference to "[PATCH][RT] netpoll: Always take poll_lock when doing polling" >> >> [ Alison, can you try this patch ] >> Sebastian follows up: >> >Alison, did you try it? I wrote: >> I did try that patch, but it hasn't made much difference. Let me >> back up and

Re: [PATCH][RT] netpoll: Always take poll_lock when doing polling

On Sun, 5 Jun 2016 08:16:58 -0700 Alison Chaiken wrote: > Steven Rostedt suggests in reference to "[PATCH][RT] netpoll: Always > take poll_lock when doing polling" > >> [ Alison, can you try this patch ] > > Sebastian follows up: > >Alison, did you try it? > >

Re: [PATCH][RT] netpoll: Always take poll_lock when doing polling

Steven Rostedt suggests in reference to "[PATCH][RT] netpoll: Always take poll_lock when doing polling" >> [ Alison, can you try this patch ] Sebastian follows up: >Alison, did you try it? Sorry for not responding sooner. I was hoping to come to a complete understanding of the system before

Re: [PATCH][RT] netpoll: Always take poll_lock when doing polling

On Thu, 2 Jun 2016 18:12:35 +0200 Sebastian Andrzej Siewior wrote: > * Steven Rostedt | 2016-05-26 19:56:41 [-0400]: > > >[ Alison, can you try this patch ] > > Alison, did you try it? > > Sebastian This patch may help too... -- Steve >From

Re: [PATCH][RT] netpoll: Always take poll_lock when doing polling

* Steven Rostedt | 2016-05-26 19:56:41 [-0400]: >[ Alison, can you try this patch ] Alison, did you try it? Sebastian