From: Alexey Dobriyan <adobriyan@gmail.com>
To: Brian Gerst <brgerst@gmail.com>
Cc: the arch/x86 maintainers <x86@kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] x86: branchless clear_page()
Date: Tue, 23 Aug 2016 19:15:03 +0300 [thread overview]
Message-ID: <20160823161502.GA1842@p183.telecom.by> (raw)
In-Reply-To: <CAMzpN2gsgEdk5SgsyzP8mwgtta4-nYjEui9Cw3CHkRXoxVVsZg@mail.gmail.com>
On Tue, Aug 23, 2016 at 09:43:25AM -0400, Brian Gerst wrote:
> > -ENTRY(clear_page_c_e)
> > +ENTRY(clear_page_rep_stosb)
> > movl $4096,%ecx
> > xorl %eax,%eax
> > rep stosb
> > ret
> > -ENDPROC(clear_page_c_e)
> > +ENDPROC(clear_page_rep_stosb)
>
> I like this idea, but does it make sense to take it a step further and
> inline the string instruction alternatives to avoid a call altogether?
It is easy but you can't do runtime patching then.
> Also, 32-bit should be converted to do the same thing as 64-bit.
I don't run 32-bit. :-)
next prev parent reply other threads:[~2016-08-23 16:14 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-08-22 20:52 [PATCH] x86: branchless clear_page() Alexey Dobriyan
2016-08-22 20:54 ` Alexey Dobriyan
2016-08-22 21:06 ` Borislav Petkov
2016-08-23 10:46 ` Alexey Dobriyan
2016-08-23 13:43 ` Brian Gerst
2016-08-23 16:15 ` Alexey Dobriyan [this message]
2016-08-23 16:19 ` [PATCH 1/3] " Alexey Dobriyan
2016-08-23 16:25 ` [PATCH 2/3] x86: support REP MOVSB copy_page() Alexey Dobriyan
2016-08-23 16:28 ` [PATCH 3/3] x86: branchless copy_page() Alexey Dobriyan
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