From: Sagi Grimberg <sagig@dev.mellanox.co.il>
To: Ming Lei <ming.lei@canonical.com>, Jens Axboe <axboe@kernel.dk>,
linux-kernel@vger.kernel.org
Cc: linux-block@vger.kernel.org,
Christoph Hellwig <hch@infradead.org>,
stable@vger.kernel.org
Subject: Re: [PATCH 1/4] block: bio: introduce helpers to get the 1st and last bvec
Date: Mon, 15 Feb 2016 10:19:49 +0200 [thread overview]
Message-ID: <56C18A25.50803@dev.mellanox.co.il> (raw)
In-Reply-To: <1455519687-23873-2-git-send-email-ming.lei@canonical.com>
> +/*
> + * bio_get_last_bvec() is introduced to get the last bvec of one
> + * bio for bio_will_gap().
> + *
> + * TODO: make it more efficient.
> + */
> +static inline void bio_get_last_bvec(struct bio *bio, struct bio_vec *bv)
> +{
> + struct bvec_iter iter;
> +
> + bio_for_each_segment(*bv, bio, iter)
> + if (bv->bv_len == iter.bi_size)
> + break;
> +}
This helper is used for each req/bio once or more. I'd say
it's critical to make it efficient and not settle for
a quick bail for drivers that don't have a virt_boundary
like you did in patch #2.
However, given that it's a regression bug fix I'm not sure it's the best
idea to add logic here.
next prev parent reply other threads:[~2016-02-15 8:19 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <1455519687-23873-1-git-send-email-ming.lei@canonical.com>
2016-02-15 7:01 ` [PATCH 1/4] block: bio: introduce helpers to get the 1st and last bvec Ming Lei
2016-02-15 8:19 ` Sagi Grimberg [this message]
2016-02-15 9:42 ` Ming Lei
2016-02-15 20:06 ` Sagi Grimberg
2016-02-16 13:03 ` Ming Lei
2016-02-17 3:08 ` Elliott, Robert (Persistent Memory)
2016-02-18 4:24 ` Kent Overstreet
2016-02-18 6:16 ` Ming Lei
2016-02-19 1:47 ` Ming Lei
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