netdev
[Top] [All Lists]

Re: [timers] net/core/*

To: kuznet@xxxxxxxxxxxxx
Subject: Re: [timers] net/core/*
From: Andi Kleen <ak@xxxxxx>
Date: Wed, 31 May 2000 21:21:44 +0200
Cc: Andrew Morton <andrewm@xxxxxxxxxx>, netdev@xxxxxxxxxxx
In-reply-to: <200005311903.XAA23547@ms2.inr.ac.ru>; from kuznet@ms2.inr.ac.ru on Wed, May 31, 2000 at 09:05:06PM +0200
References: <39352AB3.7C609B8C@uow.edu.au> <200005311903.XAA23547@ms2.inr.ac.ru>
Sender: owner-netdev@xxxxxxxxxxx
On Wed, May 31, 2000 at 09:05:06PM +0200, kuznet@xxxxxxxxxxxxx wrote:
> 
> It is consequence of too careful reading intel and alpha programmer's
> guides. 8) All of them require to help static branch prediction
> and not to jump forward in the most frequent path. It looks silly, when done
> in C, but gcc has no means to do this in different way.

gcc 3.0 will fix this, with -freorder-blocks (which knows some common
heuristics like == NULL is usually not taken already) and __builtin_expect() 

it'll allow exorcise of about a zillion gotos from the kernel tree.

-Andi

<Prev in Thread] Current Thread [Next in Thread>