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Date: Fri, 20 Jul 2007 18:12:53 +0800
From: "rae l" <crquan@gmail.com>
To: "Dave Young" <hidave.darkstar@gmail.com>
Subject: Re: [PATCH] fs/fuse/dev.c: use zero_user_page instead
Cc: "Miklos Szeredi" <miklos@szeredi.hu>, fuse-devel@lists.sourceforge.net,
       viro@zeniv.linux.org.uk, linux-kernel@vger.kernel.org
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On 7/20/07, Dave Young <hidave.darkstar@gmail.com> wrote:
> > -       if (page && zeroing && count < PAGE_SIZE) {
> > -               void *mapaddr = kmap_atomic(page, KM_USER1);
> > -               memset(mapaddr, 0, PAGE_SIZE);
> > -               kunmap_atomic(mapaddr, KM_USER1);
> > -       }
> > +       if (page && zeroing && count < PAGE_SIZE)
> > +               zero_user_page(page, 0, PAGE_SIZE, KM_USER1);
> Why clear all page? IMHO,only count bytes need to be cleared.
The original one is memset(mapaddr, 0, PAGE_SIZE), namely clear the whole page.

-- 
Denis Cheng
Linux Application Developer

"One of my most productive days was throwing away 1000 lines of code."
 - Ken Thompson.