Re: -rt more realtime scheduling issues

2007-10-10 Thread Mike Kravetz
On Wed, Oct 10, 2007 at 07:50:52AM -0400, Steven Rostedt wrote: > On Tue, Oct 09, 2007 at 11:49:53AM -0700, Mike Kravetz wrote: > > The more I try understand the IPI handling the more confused I get. :( > > At fist I was concerned about an IPI happening in the middle of the > > __schedule routine.

Re: -rt more realtime scheduling issues

2007-10-10 Thread Steven Rostedt
On Tue, Oct 09, 2007 at 11:49:53AM -0700, Mike Kravetz wrote: > The more I try understand the IPI handling the more confused I get. :( > At fist I was concerned about an IPI happening in the middle of the > __schedule routine. But, then it occurred to me that interrupts are > disabled when in

Re: -rt more realtime scheduling issues

2007-10-10 Thread Steven Rostedt
On Tue, Oct 09, 2007 at 11:49:53AM -0700, Mike Kravetz wrote: The more I try understand the IPI handling the more confused I get. :( At fist I was concerned about an IPI happening in the middle of the __schedule routine. But, then it occurred to me that interrupts are disabled when in this

Re: -rt more realtime scheduling issues

2007-10-10 Thread Mike Kravetz
On Wed, Oct 10, 2007 at 07:50:52AM -0400, Steven Rostedt wrote: On Tue, Oct 09, 2007 at 11:49:53AM -0700, Mike Kravetz wrote: The more I try understand the IPI handling the more confused I get. :( At fist I was concerned about an IPI happening in the middle of the __schedule routine. But,

Re: -rt more realtime scheduling issues

2007-10-09 Thread Mike Kravetz
On Mon, Oct 08, 2007 at 11:04:12PM -0400, Steven Rostedt wrote: > On Mon, Oct 08, 2007 at 11:45:23AM -0700, Mike Kravetz wrote: > > Are these accurate statements? I'll start working on a reliable delivery > > mechanism for RealTime scheduling. But, I just want to make sure that > > is really

Re: -rt more realtime scheduling issues

2007-10-09 Thread Peter Zijlstra
On Mon, 2007-10-08 at 23:04 -0400, Steven Rostedt wrote: > On Mon, Oct 08, 2007 at 11:45:23AM -0700, Mike Kravetz wrote: > > On Fri, Oct 05, 2007 at 07:15:48PM -0700, Mike Kravetz wrote: > > > After applying the fix to try_to_wake_up() I was still seeing some large > > > latencies for realtime

Re: -rt more realtime scheduling issues

2007-10-09 Thread Peter Zijlstra
On Mon, 2007-10-08 at 23:04 -0400, Steven Rostedt wrote: On Mon, Oct 08, 2007 at 11:45:23AM -0700, Mike Kravetz wrote: On Fri, Oct 05, 2007 at 07:15:48PM -0700, Mike Kravetz wrote: After applying the fix to try_to_wake_up() I was still seeing some large latencies for realtime tasks.

Re: -rt more realtime scheduling issues

2007-10-09 Thread Mike Kravetz
On Mon, Oct 08, 2007 at 11:04:12PM -0400, Steven Rostedt wrote: On Mon, Oct 08, 2007 at 11:45:23AM -0700, Mike Kravetz wrote: Are these accurate statements? I'll start working on a reliable delivery mechanism for RealTime scheduling. But, I just want to make sure that is really necessary.

Re: -rt more realtime scheduling issues

2007-10-08 Thread Steven Rostedt
On Mon, Oct 08, 2007 at 11:45:23AM -0700, Mike Kravetz wrote: > On Fri, Oct 05, 2007 at 07:15:48PM -0700, Mike Kravetz wrote: > > After applying the fix to try_to_wake_up() I was still seeing some large > > latencies for realtime tasks. > > I've been looking for places in the code where

Re: -rt more realtime scheduling issues

2007-10-08 Thread Mike Kravetz
On Fri, Oct 05, 2007 at 07:15:48PM -0700, Mike Kravetz wrote: > After applying the fix to try_to_wake_up() I was still seeing some large > latencies for realtime tasks. I've been looking for places in the code where reschedule IPIs should be sent in the case of 'overload' to redistribute RealTime

Re: -rt more realtime scheduling issues

2007-10-08 Thread Mike Kravetz
On Fri, Oct 05, 2007 at 07:15:48PM -0700, Mike Kravetz wrote: After applying the fix to try_to_wake_up() I was still seeing some large latencies for realtime tasks. I've been looking for places in the code where reschedule IPIs should be sent in the case of 'overload' to redistribute RealTime

Re: -rt more realtime scheduling issues

2007-10-08 Thread Steven Rostedt
On Mon, Oct 08, 2007 at 11:45:23AM -0700, Mike Kravetz wrote: On Fri, Oct 05, 2007 at 07:15:48PM -0700, Mike Kravetz wrote: After applying the fix to try_to_wake_up() I was still seeing some large latencies for realtime tasks. I've been looking for places in the code where reschedule IPIs

-rt more realtime scheduling issues

2007-10-05 Thread Mike Kravetz
Hi Ingo, After applying the fix to try_to_wake_up() I was still seeing some large latencies for realtime tasks. Some debug code pointed out two additional causes of these latencies. I have put fixes into my 'old' kernel and the scheduler related latencies have gone away. I'm pretty confident

-rt more realtime scheduling issues

2007-10-05 Thread Mike Kravetz
Hi Ingo, After applying the fix to try_to_wake_up() I was still seeing some large latencies for realtime tasks. Some debug code pointed out two additional causes of these latencies. I have put fixes into my 'old' kernel and the scheduler related latencies have gone away. I'm pretty confident