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From: Michal Sojka <sojkam1@fel.cvut.cz>
To: Christophe Leroy <christophe.leroy@c-s.fr>,
	Benjamin Herrenschmidt <benh@kernel.crashing.org>,
	Paul Mackerras <paulus@samba.org>,
	Michael Ellerman <mpe@ellerman.id.au>,
	scottwood@freescale.com
Cc: linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org
Subject: Re: [PATCH v3] powerpc32: memset: only use dcbz once cache is enabled
Date: Mon, 14 Sep 2015 09:15:00 +0200	[thread overview]
Message-ID: <87bnd5xyiz.fsf@steelpick.2x.cz> (raw)
In-Reply-To: <20150914062159.353701A2413@localhost.localdomain>

On Mon, Sep 14 2015, Christophe Leroy wrote:
> memset() uses instruction dcbz to speed up clearing by not wasting time
> loading cache line with data that will be overwritten.
> Some platform like mpc52xx do no have cache active at startup and
> can therefore not use memset(). Allthough no part of the code
> explicitly uses memset(), GCC may makes calls to it.
>
> This patch modifies memset() such that at startup, memset()
> unconditionally jumps to simple_memset() which doesn't use
> the dcbz instruction.

I tested both v3 patches (memcpy and memset) and they work for me.

Thanks
-Michal

  reply	other threads:[~2015-09-14  7:15 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-09-14  6:21 [PATCH v3] powerpc32: memset: only use dcbz once cache is enabled Christophe Leroy
2015-09-14  7:15 ` Michal Sojka [this message]
2015-09-14 15:20 ` Scott Wood
2015-09-14 15:44   ` Christophe LEROY
2015-09-14 16:13     ` Scott Wood
2015-09-14 23:52       ` Michael Ellerman

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