On Sunday 25 March 2007 22:32, Gene Heskett wrote: > On Sunday 25 March 2007, Con Kolivas wrote: > >On Sunday 25 March 2007 21:46, Con Kolivas wrote: > >> On Sunday 25 March 2007 21:34, malc wrote: > >> > On Sun, 25 Mar 2007, Ingo Molnar wrote: > >> > > * Con Kolivas <[EMAIL PROTECTED]> wrote: > >> > >> For an rsdl 0.33 patched kernel. Comments? Overhead worth it? > >> > > > >> > > we want to do this - and we should do this to the vanilla > >> > > scheduler first and check the results. I've back-merged the patch > >> > > to before RSDL and have tested it - find the patch below. Vale, > >> > > could you try this patch against a 2.6.21-rc4-ish kernel and > >> > > re-test your testcase? > >> > > >> > [..snip..] > >> > > >> > Compilation failed with: > >> > kernel/built-in.o(.sched.text+0x564): more undefined references to > >> > `__udivdi3' follow > >> > > >> > $ gcc --version | head -1 > >> > gcc (GCC) 3.4.6 > >> > > >> > $ cat /proc/cpuinfo | grep cpu > >> > cpu : 7447A, altivec supported > >> > > >> > Can't say i really understand why 64bit arithmetics suddenly became > >> > an issue here. > >> > >> Probably due to use of: > >> > >> #define NS_TO_JIFFIES(TIME) ((TIME) / (1000000000 / HZ)) > >> #define JIFFIES_TO_NS(TIME) ((TIME) * (1000000000 / HZ)) > >> > >> Excuse our 64bit world while we strive to correct our 32bit blindness > >> and fix this bug. > > > >Please try this (akpm please don't include till we confirm it builds on > > ppc, sorry). For 2.6.21-rc4 > > > >--- > >Currently we only do cpu accounting to userspace based on what is > >actually happening precisely on each tick. The accuracy of that > >accounting gets progressively worse the lower HZ is. As we already keep > >accounting of nanosecond resolution we can accurately track user cpu, > >nice cpu and idle cpu if we move the accounting to update_cpu_clock with > >a nanosecond cpu_usage_stat entry. This increases overhead slightly but > >avoids the problem of tick aliasing errors making accounting unreliable.
> > I'm playing again because the final 2.6.20.4 does NOT break amanda, where > 2.6.20.4-rc1 did. Yes only the original version I posted on this email thread was for an RSDL 0.33 patched kernel. That original patch should build fine on i386 and x86_64 (where I tried it). This version I sent out following Ingo's lead has 2.6.21-rc4 in mind (without rsdl). -- -ck - 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/
