On Sun, 2007-07-08 at 15:36 -0700, Fernando Lopez-Lezcano wrote: > On Sat, 2007-07-07 at 11:24 +0200, Ingo Molnar wrote: > > * Fernando Lopez-Lezcano <[EMAIL PROTECTED]> wrote: > > > > > Changes since 2.6.21.5-rt18: > > > > > > > > > > - Fixed a nasty and hard to track down slowness / boot problem on SMP > > > > > machines with CONFIG_NOHZ enabled. The problem was caused by the timer > > > > > wheel base lock held during the get_next_timer_interrupt() call in the > > > > > idle path, which eventually led to a bogus PI boosting of the idle > > > > > task > > > > > and in consequence a stale wrong scheduler selection for the affected > > > > > idle > > > > > task. > > > > > > > > > > Kudos to Carsten Emde, who patiently and meticulously isolated the > > > > > problem and provided the traces, which allowed to identify the root > > > > > cause. > > > > > > > > > > Problem solution: Prevent idle task boosting > > > > > > Maybe someone remember me whining about troubles with 2.6.21-rt2..18 > > > > on my Core2 T7200 laptop (fujitsu-siemens amilo i1520). > > > > > > > > Althought I'm still with my fingers crossed, I can tell the good > > > > news are that 2.6.21.5-rt19 (and -rt20) does behave far better now > > > > on the very same box. > > > > > > Yes, it works much better indeed... > > > > > > Ingo: is there a place where I can read about the changes in different > > > rtxx releases? What is new/better/fixed in rt20? (I see scheduler > > > stuff in a diff from rt19 to rt20 but I don't really know what it > > > means). > > > > and rt18 was a -rt-only NOHZ fix, that bug got introduced in rt11 when > > CFS was merged. > > > > i _think_ Rui might have seen two separate problems. Perhaps by the time > > we fixed the first problem (which Rui saw since -rt2) we introduced the > > other one via -rt11 - which then got fixed in -rt19. > > Ahh, CFS is now part of rt, I was obviously not paying attention... I'm > really trying to provide a "stable" rt kernel for audio usage and > including another subsystem into rt is - IMHO - not going to help. > What's the chance of splitting things? > > > btw., we'd love to get more feedback regarding CFS. CFS is a completely > > new scheduler for Linux. > > Then I'd rather have it separate from rt.
Please? I would like to provide the least ammount of new functionality that is really necessary in my audio kernels. Audio related requirements include the rt patch but not a new scheduler. > > It has a design centered around keeping > > application latencies down, so it is ultimately real-time friendly, and > > it should also make things work better for desktop-ish and audio-ish > > stuff as well. (even under SCHED_OTHER) > > Maybe this is CFS related? (tail of a thread in the Planet CCRMA mailing > list): > > On Sun, 2007-07-08 at 15:26 -0400, Hector Centeno wrote: > > Ok, so just to confirm, that 2.6.21-0182.rt19.1.fc7.ccrmart works fine > > on my desktop but on my laptop it makes Firefox and Tomboy to crash. > > On the same laptop using 2.6.21-0182.rt17.1.fc7.ccrmart there is no > > problem. It looks to my untrained eye like it is CFS related, I'm attaching the last part of the strace of firefox while it tries to load a flash site. The firefox process is left in an unkillable (not even by -9) state. What else could I provide to debug the problem? (this is in a T61 laptop with the Intel 7700 processor). -- Fernando - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
