lkml.org 
[lkml]   [2007]   [Nov]   [19]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
SubjectRe: CONFIG_IRQBALANCE for 64-bit x86 ?
Date
Tuesday 20 November 2007 Tarihinde 06:12:21 yazmıştı:
> On 32-bit x86, we have CONFIG_IRQBALANCE available,
> but not on 64-bit x86. Why not?
>
> I ask, because this feature seems almost essential to obtaining
> reasonable latencies during heavy I/O with fast devices.
>
> My 32-bit Core2Duo MythTV box drops audio frames without it,
> but works perfectly *with* IRQBALANCE.
>
> My QuadCore box works very well in 32-bit mode with IRQBALANCE,
> but responsiveness sucks bigtime when run in 64-bit mode (no IRQBALANCE)
> during periods of multiple heavy I/O streams (USB flash drives).
>
> That's with both the 32 and 64 bit versions of Kubuntu Gutsy,
> so the software uses pretty much identical versions either way.
>
> As near as I can tell, when IRQBALANCE is not configured,
> all I/O device interrupts go to CPU#0.
>
> I don't think our CPU scheduler takes that into account when assigning
> tasks to CPUs, so anything sent to CPU0 runs with very high latencies.
>
> Or something like that.
>
> Why no IRQ_BALANCE in 64-bit mode ?

Have you tried running irqbalance on userspace? Checkout
http://irqbalance.org/ . AFAIK CONFIG_IRQBALANCE is deprecated and eats
battery power.

Regards,
ismail

--
Faith is believing what you know isn't so -- Mark Twain
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2007-11-20 05:19    [W:0.065 / U:0.240 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site