>>> On Mon, Jun 30, 2008 at 9:15 AM, in message <20080630131511.GA7506@xxxxxxx>, Ingo Molnar <mingo@xxxxxxx> wrote: > * Gregory Haskins <ghaskins@xxxxxxxxxx> wrote: > >> Hi Ingo, >> The following patches apply to linux-tip/sched/devel and enhance the >> performance of the kernel (specifically in PREEMPT_RT, though they do >> not regress mainline performance as far as I can tell). They offer >> somewhere between 50-100% speedups in netperf performance, depending >> on the test. > > -tip testing found this boot hang: Ok, I dug in a little bit here. I haven't verified this out yet, but I think the problem is that your config is PREEMPT_VOLUNTARY which NOPs the preempt_disable() in schedule() that I rely on to allow the lock to be dropped. (Doh!) One way I can fix this is to fixup the newidle() code to only play the irq dropping tricks ifdef CONFIG_PREEMPT == TRUE. Does this sound reasonable, or is there a better way to address this? -Greg > > Linux version 2.6.26-rc8-tip (mingo@dione) (gcc version 4.2.3) #12917 > SMP Mon Jun 30 15:06:32 CEST 2008 > [...] > CPU 1/1 -> Node 0 > CPU: Physical Processor ID: 0 > CPU: Processor Core ID: 1 > CPU1: AMD Athlon(tm) 64 X2 Dual Core Processor 3800+ stepping 02 > Brought up 2 CPUs > Total of 2 processors activated (8041.15 BogoMIPS). > [ hard hang ] > > with this config: > > http://redhat.com/~mingo/misc/config-Mon_Jun_30_14_54_19_CEST_2008.bad > > full bootlog: > > http://redhat.com/~mingo/misc/hang-Mon_Jun_30_14_54_19_CEST_2008.bad > > it should continue with this bootup sequence: > > calling net_ns_init+0x0/0x1a0 > net_namespace: 376 bytes > initcall net_ns_init+0x0/0x1a0 returned 0 after 0 msecs > calling init_smp_flush+0x0/0x60 > > i've bisected it down to: > > -------------- > | commit cc8160c56843201891766660e3816d2e546c1b17 > | Author: Gregory Haskins <ghaskins@xxxxxxxxxx> > | Date: Fri Jun 27 14:29:50 2008 -0600 > | > | sched: enable interrupts and drop rq-lock during newidle balancing > -------------- > > so i've reverted that change for now. > > Ingo -- To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
