Re: [RFC][PATCH 0/5] Signal scalability series

From: Matt Fleming
Date: Mon Oct 03 2011 - 11:44:00 EST


On Mon, 2011-10-03 at 08:28 -0700, Linus Torvalds wrote:
> On Sat, Oct 1, 2011 at 2:35 AM, Matt Fleming <matt@xxxxxxxxxxxxxxxxx> wrote:
> >
> > You and me both. Unfortunately, the ia64 guys had a different opinion,
> > http://www.spinics.net/lists/linux-ia64/msg08363.html
>
> Well, considering that it apparently slows down the single-threaded
> case by 50% on an architecture that actually *matters*, I think the
> whole discussion is somewhat academic, don't you?
>
> "Scalability" is pretty much never a valid excuse for "slows down the
> common case".

Where did you get the 50% slow down figure from?

Oh, are you referring to Oleg's email about the slow down under kvm?
Yeah, admittedly that's a pretty clear indicator that something is wrong
with the approach in this patch series.

I thought I'd replied to that email but I guess not.

--
Matt Fleming, Intel Open Source Technology Center

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