Subject: Re: [PATCH] blk: improve order of bio handling in
 generic_make_request()
To: NeilBrown <neilb@suse.com>, Jack Wang <jinpu.wang@profitbricks.com>
References: <87h93blz6g.fsf@notabene.neil.brown.name>
 <71562c2c-97f4-9a0a-32ec-30e0702ca575@profitbricks.com>
 <87lgsjj9w8.fsf@notabene.neil.brown.name>
Cc: LKML <linux-kernel@vger.kernel.org>,
        Lars Ellenberg <lars.ellenberg@linbit.com>,
        Kent Overstreet <kent.overstreet@gmail.com>,
        Pavel Machek <pavel@ucw.cz>, Mike Snitzer <snitzer@redhat.com>,
        Mikulas Patocka <mpatocka@redhat.com>
From: Jens Axboe <axboe@kernel.dk>
Message-ID: <a674456d-fb93-437e-c50e-195e7a035ba4@kernel.dk>
Date: Mon, 6 Mar 2017 13:18:05 -0700
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On 03/05/2017 09:40 PM, NeilBrown wrote:
> On Fri, Mar 03 2017, Jack Wang wrote:
>>
>> Thanks Neil for pushing the fix.
>>
>> We can optimize generic_make_request a little bit:
>> - assign bio_list struct hold directly instead init and merge
>> - remove duplicate code
>>
>> I think better to squash into your fix.
> 
> Hi Jack,
>  I don't object to your changes, but I'd like to see a response from
>  Jens first.
>  My preference would be to get the original patch in, then other changes
>  that build on it, such as this one, can be added.  Until the core
>  changes lands, any other work is pointless.
> 
>  Of course if Jens wants a this merged before he'll apply it, I'll
>  happily do that.

I like the change, and thanks for tackling this. It's been a pending
issue for way too long. I do think we should squash Jack's patch
into the original, as it does clean up the code nicely.

Do we have a proper test case for this, so we can verify that it
does indeed also work in practice?

-- 
Jens Axboe