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From: Rusty Russell <rusty@rustcorp.com.au>
To: "Srivatsa S. Bhat" <srivatsa.bhat@linux.vnet.ibm.com>,
        Eric Dumazet <eric.dumazet@gmail.com>
Cc: akpm@linux-foundation.org, kosaki.motohiro@gmail.com,
        linux-kernel@vger.kernel.org, venki@google.com,
        Mike Travis <travis@sgi.com>
Subject: Re: [PATCH] lib/cpumask.c: Optimize __any_online_cpu() calculation
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References: <20120215123208.15623.73499.stgit@srivatsabhat.in.ibm.com> <1329310627.2437.18.camel@edumazet-HP-Compaq-6005-Pro-SFF-PC> <4F3BBED4.2090101@linux.vnet.ibm.com>
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Date: Thu, 16 Feb 2012 09:21:23 +1030
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On Wed, 15 Feb 2012 19:49:00 +0530, "Srivatsa S. Bhat" <srivatsa.bhat@linux.vnet.ibm.com> wrote:
> On 02/15/2012 06:27 PM, Eric Dumazet wrote:
> 
> > Le mercredi 15 février 2012 à 18:05 +0530, Srivatsa S. Bhat a écrit :
> >> __any_online_cpu() uses a for loop at the moment.
> >> Instead, use cpumask_* operations to speed it up.
> >>
> >> Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
> >> ---
> >> Actually, the patch posted at https://lkml.org/lkml/2012/2/15/101 removed
> >> the last user of any_online_cpu() (and hence __any_online_cpu()).
> >> However, since this is an exported symbol, I refrained from removing this
> >> function altogether.
> > 
> > Just remove the export/function and eventually leave the helper ?
> > 
> > #define any_online_cpu(mask) cpumask_any_and(mask, cpu_online_mask)
> > 
> 
> 
> That sounds good. Here is v2 of the patch.
> (Since this v2 touches include/linux/cpumask.h, I rebased it on top of the
> patch posted at: https://lkml.org/lkml/2012/2/15/2. Even without that
> patch it should apply with minor line number changes..)

No.  Just git rid of the only caller of any_online_cpu():

arch/ia64/kernel/smpboot.c:693:			new_cpei_cpu = any_online_cpu(cpu_online_map);

Thanks,
Rusty.