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Date:   Thu, 12 Dec 2019 04:52:22 -0800
From:   Christoph Hellwig <hch@infradead.org>
To:     Christophe Leroy <christophe.leroy@c-s.fr>
Cc:     Benjamin Herrenschmidt <benh@kernel.crashing.org>,
        Paul Mackerras <paulus@samba.org>,
        Michael Ellerman <mpe@ellerman.id.au>,
        linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v5] powerpc/irq: inline call_do_irq() and
 call_do_softirq() on PPC32
Message-ID: <20191212125222.GB3381@infradead.org>
References: <72a6cd86137b2a7ab835213cf5c74df6ed2f6ea7.1575739197.git.christophe.leroy@c-s.fr>
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On Sat, Dec 07, 2019 at 05:20:04PM +0000, Christophe Leroy wrote:
> call_do_irq() and call_do_softirq() are simple enough to be
> worth inlining.
> 
> Inlining them avoids an mflr/mtlr pair plus a save/reload on stack.
> It also allows GCC to keep the saved ksp_limit in an nonvolatile reg.
> 
> This is inspired from S390 arch. Several other arches do more or
> less the same. The way sparc arch does seems odd thought.

Any reason you only do this for 32-bit and not 64-bit as well?