Message-ID: <4FBDF5E5.7010806@intel.com>
Date: Thu, 24 May 2012 16:48:37 +0800
From: Alex Shi <alex.shi@intel.com>
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To: Peter Zijlstra <a.p.zijlstra@chello.nl>
CC: Jan Beulich <JBeulich@suse.com>, borislav.petkov@amd.com, arnd@arndb.de,
        akinobu.mita@gmail.com, eric.dumazet@gmail.com, fweisbec@gmail.com,
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        cpw@sgi.com, steiner@sgi.com, linux-kernel@vger.kernel.org,
        viro@zeniv.linux.org.uk, hpa@zytor.com,
        Rusty Russell <rusty@rustcorp.com.au>
Subject: Re: [PATCH v7 8/8] x86/tlb: just do tlb flush on one of siblings
 of SMT
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On 05/24/2012 04:42 PM, Peter Zijlstra wrote:

> On Thu, 2012-05-24 at 16:32 +0800, Alex Shi wrote:
>> So, I use cpumask_t in stack.
> 
> cpumask_t is 512 bytes with NR_CPUS=4096, that's generally considered
> too big to be on stack.
> 
> A number of people spend a lot of time removing cpumask_t from stacks a
> while ago, I'm very sure they'll not be happy if you're going to add it
> back.


In my testing, allocate a cpumask_var_t is more worse than cpumask_t.
So, another choice is using percpu pre-allocatd cpumask for this, but I
am wondering if it is acceptable. What's suggestion for this point?

> 
> Rusty, what was the plan on removing cpumask_t altogether?
> 


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