netdev
[Top] [All Lists]

Re: [PATCH/RFC] Reduce call chain length in netfilter

To: "David S. Miller" <davem@xxxxxxxxxxxxx>
Subject: Re: [PATCH/RFC] Reduce call chain length in netfilter
From: Bart De Schuymer <bdschuym@xxxxxxxxxx>
Date: Thu, 27 Jan 2005 22:16:04 +0100
Cc: Patrick McHardy <kaber@xxxxxxxxx>, netdev@xxxxxxxxxxx, netfilter-devel@xxxxxxxxxxxxxxxxxxx, snort2004@xxxxxxx, rusty@xxxxxxxxxxxxxxx, ak@xxxxxxx, bridge@xxxxxxxx, gandalf@xxxxxxxxxxxxxx, dwmw2@xxxxxxxxxxxxx, shemminger@xxxxxxxx
In-reply-to: <20050127114726.2205b4ed.davem@xxxxxxxxxxxxx>
References: <1131604877.20041218092730@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx> <p73zn0ccaee.fsf@xxxxxxxxxxxxx> <1105117559.11753.34.camel@xxxxxxxxxxxxxxxxxxxxxxx> <20050107100017.454ddadc@xxxxxxxxxxxxxxxxx> <1105133241.3375.16.camel@xxxxxxxxxxxxxxxxxxxxx> <20050118135735.4b77d38d.davem@xxxxxxxxxxxxx> <1106433059.4486.11.camel@xxxxxxxxxxxxxxxxxxxxx> <1106436153.20995.42.camel@xxxxxxxxxxxxxx> <1106484019.3376.5.camel@xxxxxxxxxxxxxxxxxxxxx> <1106496509.1085.1.camel@xxxxxxxxxxxxxx> <20050125220558.6e824f8a.davem@xxxxxxxxxxxxx> <1106730510.4041.4.camel@xxxxxxxxxxxxxxxxxxxxx> <41F82C6D.7020006@xxxxxxxxx> <20050126231801.7bf90338.davem@xxxxxxxxxxxxx> <41F929FA.3050800@xxxxxxxxx> <20050127114726.2205b4ed.davem@xxxxxxxxxxxxx>
Sender: netdev-bounce@xxxxxxxxxxx
Op do, 27-01-2005 te 11:47 -0800, schreef David S. Miller:
> On Thu, 27 Jan 2005 18:50:50 +0100
> Patrick McHardy <kaber@xxxxxxxxx> wrote:
> 
> >  From what I can see it doesn't generate tail-calls currently:
> 
> Indeed... It even doesn't do this on Sparc64 either, even for
> the okfn(skb) call which I was sure it would.
> 
> It won't tail-call for function pointers for some strance reason
> as exhibited by this simple test:
> 
> struct sk_buff {
>       int foo;
> };
> 
> int invoke(struct sk_buff *skb, int (*okfn)(struct sk_buff *))
> {
>       return okfn(skb);
> }
> 
> extern int test_func(struct sk_buff *);
> 
> int invoke2(struct sk_buff *skb)
> {
>       return test_func(skb);
> }
> 
> In the generated asm on sparc64, invoke2() gets a tail-call
> whereas invoke() does not.  Hmmm...

Pasha (<snort2004@xxxxxxx>) is currently using a bridge-nf patch vs
2.4.29 with the changes I sent to you. After two days he sent me
(yesterday) a message that all is well. Without the patch he was getting
the stack overflow oopses.

cheers,
Bart



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