From: Jens Axboe <axboe@kernel.dk>
To: Ming Lei <ming.lei@canonical.com>, linux-kernel@vger.kernel.org
Cc: Christoph Hellwig <hch@infradead.org>,
Kent Overstreet <kent.overstreet@gmail.com>,
Ming Lin <ming.l@ssi.samsung.com>, Dongsu Park <dpark@posteo.net>
Subject: Re: [PATCH] block: blk-merge: fast-clone bio when splitting rw bios
Date: Thu, 17 Sep 2015 09:19:11 -0600 [thread overview]
Message-ID: <55FAD9EF.5040100@kernel.dk> (raw)
In-Reply-To: <1442502807-24377-1-git-send-email-ming.lei@canonical.com>
On 09/17/2015 09:13 AM, Ming Lei wrote:
> biovecs has become immutable since v3.13, so it isn't necessary
> to allocate biovecs for the new cloned bios, then we can save
> one extra biovecs allocation/copy, and the allocation is often
> not fixed-length and a bit more expensive.
>
> For example, if the 'max_sectors_kb' of null blk's queue is set
> as 16(32 sectors) via sysfs just for making more splits, this patch
> can increase throught about ~70% in the sequential read test over
> null_blk(direct io, bs: 1M).
I'd be curious how this compares to before we did the splitting, not
exceeding the limits through bio_add_page() instead?
--
Jens Axboe
next prev parent reply other threads:[~2015-09-17 15:19 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-09-17 15:13 Ming Lei
2015-09-17 15:19 ` Jens Axboe [this message]
2015-09-17 15:50 ` Ming Lei
2015-09-17 15:55 ` Jens Axboe
2015-09-17 16:01 ` Jens Axboe
2015-09-17 16:08 ` Ming Lei
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