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SubjectRe: [PATCH] remove redundant NULL checks before kfree() in drivers/video/
On Mon, 21 Mar 2005, Antonino A. Daplas wrote:
> On Sunday 20 March 2005 06:59, Jesper Juhl wrote:
> > Checking a pointer for NULL before calling kfree() on it is redundant,
> > kfree() deals with NULL pointers just fine.
> > This patch removes such checks from files in drivers/video/
> >
> > Since this is a fairly trivial change (and the same change made
> > everywhere) I've just made a single patch for all the files and CC all
> > authors/maintainers of those files I could find for comments. If spliting
> > this into one patch pr file is prefered, then I can easily do that as
> > well.
> >
>
> [snip]
>
> > --- linux-2.6.11-mm4-orig/drivers/video/console/bitblit.c 2005-03-16
> > 15:45:26.000000000 +0100 +++
> > linux-2.6.11-mm4/drivers/video/console/bitblit.c 2005-03-19
> > 22:27:39.000000000 +0100 @@ -199,8 +199,7 @@ static void bit_putcs(struct
> > vc_data *vc
> > count -= cnt;
> > }
> >
> > - if (buf)
> > - kfree(buf);
> > + kfree(buf);
> > }
> >
>
> This is performance critical, so I would like the check to remain. A comment
> may be added in this section.

The first thing kfree() does is check for the NULL pointer. And since kfree()
is used a lot, it's probably already in the cache.

Gr{oetje,eeting}s,
Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
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