linux-kernel - Re: [PATCH v3 6/7] erofs: remove all likely/unlikely annotations

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Message-ID: <20190830115509.GN23584@kadam>
Date:   Fri, 30 Aug 2019 14:55:09 +0300
From:   Dan Carpenter <dan.carpenter@...cle.com>
To:     Chao Yu <yuchao0@...wei.com>
Cc:     Gao Xiang <gaoxiang25@...wei.com>,
        Christoph Hellwig <hch@...radead.org>,
        Joe Perches <joe@...ches.com>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        devel@...verdev.osuosl.org, linux-erofs@...ts.ozlabs.org,
        Chao Yu <chao@...nel.org>, LKML <linux-kernel@...r.kernel.org>,
        weidu.du@...wei.com, Fang Wei <fangwei1@...wei.com>,
        Miao Xie <miaoxie@...wei.com>
Subject: Re: [PATCH v3 6/7] erofs: remove all likely/unlikely annotations

On Fri, Aug 30, 2019 at 02:25:13PM +0800, Chao Yu wrote:
> On 2019/8/30 11:36, Gao Xiang wrote:
> > As Dan Carpenter suggested [1], I have to remove
> > all erofs likely/unlikely annotations.
> > 
> > [1] https://lore.kernel.org/linux-fsdevel/20190829154346.GK23584@kadam/
> > Reported-by: Dan Carpenter <dan.carpenter@...cle.com>
> > Signed-off-by: Gao Xiang <gaoxiang25@...wei.com>
> 
> I suggest we can modify this by following good example rather than removing them
> all, at least, the fuzzed random fields of disk layout handling should be very
> rare case, I guess it's fine to use unlikely.

No, no...  It's the opposite.  Only use those annotations on fast paths
where it's going to show up in benchmarks.  On fast paths then remove
all the debug code and really optimize the heck out of the code.  We
sacrifice readability for speed in places where it matters.

regards,
dan carpenter