lkml.org 
[lkml]   [2001]   [Sep]   [28]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [patch] softirq performance fixes, cleanups, 2.4.10.
On Fri, Sep 28, 2001 at 06:46:16PM +0200, Ingo Molnar wrote:
>
> On Fri, 28 Sep 2001, Andrea Arcangeli wrote:
>
> > he's allowing to repeat the loop more than once to hide it, [...]
>
> it's not done to 'hide' it in any way. I removed the mask method because
> it's redundant under the new scheme.

What you are missing is a property provided by the old method.

We have the NET_RX_SOFTIRQ that floods very heavily, so far so good.

Then we have HI_SOFTIRQ, incidentally HI_SOFTIRQ from irq wants to be
executed with very low latency, with your patch it _can_ be postpone to
ksoftirqd processing just because there's the NET_RX_SOFTIRQ cpu hog in
background. With the old method it was guaranteed that the HI_SOFTIRQ
was executed with very low latency within the irq, no matter of the
NET_RX_SOFTIRQ flood.

So there _is_ a difference, and the multiple-loop will tend to "hide"
the difference.

Andrea
-
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: 2005-03-22 13:03    [W:0.054 / U:1.272 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site