Re: [PATCH] split xfs_ioc_xattr

[Timothy Shimmin <tes@sgi.com>]

David Chinner wrote:
> On Wed, Apr 16, 2008 at 01:47:13PM +1000, Niv Sardi wrote:
>> Christoph Hellwig <hch@lst.de> writes:
>>
>>> On Mon, Apr 14, 2008 at 01:14:47PM +1000, Niv Sardi wrote:
>>>>
>>>> Christoph Hellwig <hch@lst.de> writes:
>>>>> The three subcases of xfs_ioc_xattr don't share any semantics and almost
>>>>> no code, so split it into three separate helpers.
>>>>>
>>>>> Signed-off-by: Christoph Hellwig <hch@lst.de>
>>>> Looks good to me, aren't the likely() unlinkely() deprecated ? shouldn't
>>>> they be killed ?
>>> Why would they be deprecated?
>> just an impression I had from on of Dave's comment to one of my patches:
>> « Can we kill all the likely() crap out of here? Modern hardware
>>   branch predictors are far better than static prediction hints. »
> 
> And the context which you haven't quoted? A repugnant hunk of code
> with one broken use of likely() in two unnecessary 'if
> (likely(!error) ...' branches, and 20 lines of my comment after the
> above quote demonstrating of how to restructure it so it was neater,
> faster and didn't need the prediction hints at all.
> 

I'm still wondering if likely() and unlikely() should ever be used or not?

--Tim