Re: [PATCH] jbd: Remove redundant NULL check upon kfree()

From: Jiri Kosina
Date: Wed Aug 11 2010 - 09:06:47 EST


On Wed, 11 Aug 2010, Davidlohr Bueso wrote:

> jbd: Remove redundant NULL check upon kfree().
>
> Signed-off-by: Davidlohr Bueso <dave@xxxxxxx>
> ---
> fs/jbd/transaction.c | 3 +--
> 1 files changed, 1 insertions(+), 2 deletions(-)
>
> diff --git a/fs/jbd/transaction.c b/fs/jbd/transaction.c
> index 5ae71e7..5e98130 100644
> --- a/fs/jbd/transaction.c
> +++ b/fs/jbd/transaction.c
> @@ -232,8 +232,7 @@ repeat_locked:
>
> lock_map_acquire(&handle->h_lockdep_map);
> out:
> - if (unlikely(new_transaction)) /* It's usually NULL */
> - kfree(new_transaction);
> + kfree(new_transaction);

This doesn't seem entirely redundant, as it is optimized (via the
unlikely() hint) for the opposite case than what kfree() is optimized for
(kfree() assumes that the pointer is likely non-NULL, while the code above
assumes that the pointer si likely NULL).

--
Jiri Kosina
SUSE Labs, Novell Inc.

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