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Date: Tue, 8 May 2007 10:13:52 -0700
From: "Satyam Sharma" <satyam.sharma@gmail.com>
To: "Pekka Enberg" <penberg@cs.helsinki.fi>
Subject: Re: [KJ PATCH] Replacing memset(<addr>,0,PAGE_SIZE) with clear_page() in kernel/kexec.c
Cc: "Michael Tokarev" <mjt@tls.msk.ru>,
       "Shani Moideen" <shani.moideen@wipro.com>, ebiederm@xmission.com,
       linux-kernel@vger.kernel.org, kernel-janitors@lists.osdl.org
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On 5/8/07, Pekka Enberg <penberg@cs.helsinki.fi> wrote:
> Shani Moideen wrote:
> > >                 ptr = kmap(page);
> > > -               memset(ptr, 0, PAGE_SIZE);
> > > +               clear_page(ptr);
>
> On 5/8/07, Michael Tokarev <mjt@tls.msk.ru> wrote:
> > I wonder if it's worth to invent kzmap() or something like that... ;)
>
> I am counting 59 kmap + memset pairs in the kernel, so perhaps it is
> worth it to reduce kernel text size.

Stuff of the sort already exists. Look for clear_highpage(),
clear_user_highpage() and memclear_highpage_flush (recently renamed to
zero_user_page, see -mm). But they all use kmap_atomic() -- kmap()
variants would have to be added. Also, they're all inlines, so I'm not
sure you'd be able to cut down text size, but still getting rid of
open-coding is always good.
-
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