[Devel] Re: [PATCH] Compact sk_stream_mem_schedule() code

Arnaldo Carvalho de Melo acme at ghostprotocols.net
Mon Nov 19 11:30:59 PST 2007


Em Mon, Nov 19, 2007 at 03:13:44PM +0300, Pavel Emelyanov escreveu:
> This function references sk->sk_prot->xxx for many times.
> It turned out, that there's so many code in it, that gcc 
> cannot always optimize access to sk->sk_prot's fields.
> 
> After saving the sk->sk_prot on the stack and comparing
> disassembled code, it turned out that the function became
> ~10 bytes shorter and made less dereferences (on i386 and 
> x86_64). Stack consumption didn't grow.
> 
> Besides, this patch drives most of this function into the
> 80 columns limit.
> 
> Signed-off-by: Pavel Emelyanov <xemul at openvz.org>

I wonder if making it 'const struct proto *prot = sk->sk_prot;'

would make any difference.

Acked-by: Arnaldo Carvalho de Melo <acme at redhat.com>




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