linux-kernel - Re: [PATCH] ARM: make memzero optimization smarter

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Message-ID: <nycvar.YSQ.7.76.1801171606170.13881@knanqh.ubzr>
Date:   Wed, 17 Jan 2018 16:14:17 -0500 (EST)
From:   Nicolas Pitre <nicolas.pitre@...aro.org>
To:     Russell King - ARM Linux <linux@...linux.org.uk>
cc:     Arnd Bergmann <arnd@...db.de>,
        Ard Biesheuvel <ard.biesheuvel@...aro.org>,
        Zhichang Yuan <yuanzhichang@...ilicon.com>,
        Linux ARM <linux-arm-kernel@...ts.infradead.org>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] ARM: make memzero optimization smarter

On Wed, 17 Jan 2018, Nicolas Pitre wrote:

> On Wed, 17 Jan 2018, Russell King - ARM Linux wrote:
> 
> > However, __memzero is not safe against being called with a zero length
> > so it's not something we can simply remove.
> 
> The idea is about the possibility of removing __memzero altogether.
> It is not clear that the tiny performance gain from a dedicated memzero 
> implementation is worth the current overhead around it.

This being said, I fail to see how __memzero is not safe against a zero 
length. Are you sure it isn't?


Nicolas