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Subject: Re: [PATCH v2] srcu: Isolate srcu sections using CONFIG_SRCU
From: Michael Ellerman <mpe@ellerman.id.au>
To: Pranith Kumar <bobby.prani@gmail.com>
Date: Sun, 04 Jan 2015 20:35:52 +1100
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Cc: Peter Zijlstra <peterz@infradead.org>,
 Heiko Carstens <heiko.carstens@de.ibm.com>,
 Tiejun Chen <tiejun.chen@windriver.com>, Paul Mackerras <paulus@samba.org>,
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On Tue, 2014-12-30 at 13:54 -0500, Pranith Kumar wrote:
> On Tue, Dec 30, 2014 at 1:50 PM, Peter Zijlstra <peterz@infradead.org> wrote:
> > On Tue, Dec 30, 2014 at 12:46:22AM -0500, Pranith Kumar wrote:
> >> Isolate the SRCU functions and data structures within CONFIG_SRCU so that there
> >> is a compile time failure if srcu is used when not enabled. This was decided to
> >> be better than waiting until link time for a failure to occur.
> >
> > Why?
> 
> This is part of the kernel tinification efforts. The first patch was
> posted here: https://lkml.org/lkml/2014/12/4/848. This patch enables a
> compile time failure instead of a link time failure.

The punch line was:

  "so the savings are about ~2000 bytes."

Which is utterly not worth the effort IMO. There have got to be more attractive
targets for tinification than this.

cheers