Date: Tue, 5 Apr 2016 18:34:11 -0800
From: Kent Overstreet <kent.overstreet@gmail.com>
To: Ming Lei <ming.lei@canonical.com>
Cc: Jens Axboe <axboe@fb.com>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        linux-block@vger.kernel.org, Christoph Hellwig <hch@infradead.org>,
        Eric Wheeler <bcache@lists.ewheeler.net>,
        Sebastian Roesner <sroesner-kernelorg@roesner-online.de>,
        "4.2+" <stable@vger.kernel.org>, Shaohua Li <shli@fb.com>
Subject: Re: [PATCH] block: make sure big bio is splitted into at most 256
 bvecs
Message-ID: <20160406023411.GA7793@kmo-pixel>
References: <1459878246-9249-1-git-send-email-ming.lei@canonical.com>
 <20160406003025.GC31161@kmo-pixel>
 <CACVXFVOP62+2ahfiVa9hZX5fX4C2owQDS1xSbsRdMQ3Jr-hNJg@mail.gmail.com>
 <20160406011028.GA32334@kmo-pixel>
 <CACVXFVN0MVVefbSc_5iGeQigEYxdn5pFc+aidW1mhgdv9ryF5A@mail.gmail.com>
 <20160406012839.GA32713@kmo-pixel>
 <CACVXFVO5oW_u0chDki4eRBDcA+-WAi=8kJLtEkE0cQNunk=4qg@mail.gmail.com>
 <20160406022249.GB7452@kmo-pixel>
 <CACVXFVP2i+0Pw=JwP4m-q7d8n-PAsceFpUkAntVbEeJQBS=UCQ@mail.gmail.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <CACVXFVP2i+0Pw=JwP4m-q7d8n-PAsceFpUkAntVbEeJQBS=UCQ@mail.gmail.com>
User-Agent: Mutt/1.5.24 (2015-08-30)
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 401
Lines: 9

On Wed, Apr 06, 2016 at 10:30:22AM +0800, Ming Lei wrote:
> Now limit.max_segments is for limiting segments from hw view, one this
> segment may include lots of pages/bvecs.
> 
> The current bio_clone() issue is that we can't clone from one bio which
> includes more than 256 bvecs, maybe all these 256 bvecs belong to
> one same hw segment.

So the distinction is purely a post multipage bvec thing?