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From: Eric Dumazet <dada1@cosmosbay.com>
To: Vadim Lobanov <vlobanov@speakeasy.net>
Subject: Re: [PATCH] fdset's leakage
Date: Tue, 11 Jul 2006 19:26:36 +0200
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Cc: Kirill Korotaev <dev@openvz.org>, Andrew Morton <akpm@osdl.org>,
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On Tuesday 11 July 2006 18:13, Vadim Lobanov wrote:
> > unsinged long round_up_pow_of_two(unsigned long x)
> > {
> >   unsigned long res = 1 << BITS_PER_LONG;
>
> You'll get a zero here. Should be 1 << (BITS_PER_LONG - 1).
>

Nope. It wont work on 64 bits platform :)

You want  1UL << (BITS_PER_LONG - 1).

But the roundup_pow_of_two() function is already defined in 
include/linux/kernel.h and uses fls_long()

Eric