Message-ID: <4DBC6654.5030003@redhat.com>
Date: Sat, 30 Apr 2011 22:43:16 +0300
From: Avi Kivity <avi@redhat.com>
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To: paulmck@linux.vnet.ibm.com
CC: Gleb Natapov <gleb@redhat.com>, linux-kernel@vger.kernel.org,
        mtosatti@redhat.com, kvm@vger.kernel.org
Subject: Re: [PATCH 1/2] rcu: export rcu_note_context_switch() function
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On 04/30/2011 03:59 PM, Paul E. McKenney wrote:
> >  That will work, but does making rcu_note_context_switch() out of line
> >  actually increase kernel size? The function is called in two places
> >  currently, so by making it out of line we make two calling site smaller.
> >  Will measure it next week.
>
> One thing to keep in mind...  Calling an out-of-line function from
> KVM requires an export, each of which significantly increases TINY_RCU's
> memory footprint.

I would expect that most kvm configs will actually be smp (perhaps with 
an exception for embedded ppc).

A completely random idea - how about trimming exports that aren't 
actually used?  so if you have a minimal setup you only get the hit if 
you actually use kvm.

(The trimming would need to be optional so external modules can continue 
to work for those who want them)


-- 
I have a truly marvellous patch that fixes the bug which this
signature is too narrow to contain.

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