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From: Eric Dumazet <dada1@cosmosbay.com>
To: Rusty Russell <rusty@rustcorp.com.au>
Cc: Andrew Morton <akpm@linux-foundation.org>,
	linux kernel <linux-kernel@vger.kernel.org>
Subject: Re: [PACH] smp: uninline num_online_cpus() & num_possible_cpus()
Date: Tue, 09 Dec 2008 07:36:00 +0100	[thread overview]
Message-ID: <493E11D0.6020702@cosmosbay.com> (raw)
In-Reply-To: <200812091433.03670.rusty@rustcorp.com.au>

Rusty Russell a écrit :
> On Saturday 06 December 2008 04:03:44 Eric Dumazet wrote:
>> num_online_cpus() and num_possible_cpus() are not performance
>> critical and are quite large.
>>
>> Unlining them shrinks kernel text size by 7523 bytes on x86,
>> if NR_CPUS>32
> 
> Hi Eric!
> 
>   Slight misdiagnosis, I think.  One base problem is addressed in fixing
> the bitmap operators (see "[PATCH] bitmap: test for constant as well as
> small size for inline versions" on lkml Message-Id: <200811160907.07140.rusty@rustcorp.com.au>).  This is already in
> linux-next, and I've pasted it below.
> 
>   Worse, you used the obsolete cpumask operators :)
> 

I see ! Good work ;)

So the gain would be 11 bytes per call site, and about one hundred calls,
maybe not worth it :)

Thanks



      reply	other threads:[~2008-12-09  6:36 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-12-05 17:33 [PACH] smp: uninline num_online_cpus() & num_possible_cpus() Eric Dumazet
2008-12-08 22:43 ` Andrew Morton
2008-12-09  4:03 ` Rusty Russell
2008-12-09  6:36   ` Eric Dumazet [this message]

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