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Message-ID: <15450f6ba169de8862e11bc2d20b3645958f4efd.camel@perches.com>
Subject: Re: [PATCH 1/1] block: Use bits.h macros to improve readability
From:   Joe Perches <joe@perches.com>
To:     Jens Axboe <axboe@kernel.dk>,
        Leonardo Bras <leonardo@linux.ibm.com>,
        linux-kernel@vger.kernel.org
Cc:     Dennis Zhou <dennis@kernel.org>, Hannes Reinecke <hare@suse.com>,
        Damien Le Moal <damien.lemoal@wdc.com>,
        Tejun Heo <tj@kernel.org>,
        "Dennis Zhou (Facebook)" <dennisszhou@gmail.com>,
        Johannes Thumshirn <jthumshirn@suse.de>,
        Sagi Grimberg <sagi@grimberg.me>
Date:   Sun, 04 Aug 2019 13:17:17 -0700
In-Reply-To: <a41b5530-f2e1-0932-1f39-0ce66ce902ae@kernel.dk>
References: <20190802000041.24513-1-leonardo@linux.ibm.com>
         <a41b5530-f2e1-0932-1f39-0ce66ce902ae@kernel.dk>
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On Fri, 2019-08-02 at 21:18 -0700, Jens Axboe wrote:
> On 8/1/19 6:00 PM, Leonardo Bras wrote:
> > Applies some bits.h macros in order to improve readability of
> > linux/blk_types.h.
[]
> I know precisely what that does, whereas I have to think about the other
> one, maybe even look it up to be sure. For instance, without looking
> now, I have no idea what the second argument is. Looking at the git log,
> I see numerous instances of:

While I'm not at all a proponent of GENMASK/GENMASK_ULL,
and so not a proponent of this patch, latent defects are
possible in both cases.

You'd likely have to look at SOME_SHIFT to see if it's 0
to verify the actual mask is what's really desired.

$ git grep -P '_SHIFT\s+\(?\s*0\s*\)?\b' | wc -l
11907