From: Johannes Thumshirn <jthumshirn@suse.de>
To: Ming Lei <ming.lei@redhat.com>
Cc: Jens Axboe <axboe@fb.com>,
Linux Block Layer Mailinglist <linux-block@vger.kernel.org>,
Hannes Reinecke <hare@suse.de>,
Linux Kernel Mailinglist <linux-kernel@vger.kernel.org>,
Jan Kara <jack@suse.cz>, Sagi Grimberg <sagi@grimberg.me>
Subject: Re: [PATCH] block: respect virtual boundary mask in bvecs
Date: Tue, 6 Nov 2018 13:34:03 +0100 [thread overview]
Message-ID: <3c3dd9c2-4240-7bb5-c0ff-af6f2e479c31@suse.de> (raw)
In-Reply-To: <20181105120153.GD12367@ming.t460p>
On 05/11/2018 13:01, Ming Lei wrote:
> If you mean the real huge page, this patch shouldn't have made a difference
> because bio_vec->bv_offset is in [0, PAGE_SIZE), and iSer sets virt
> boundary as 4K - 1.
>
> However, things will change after multipage bvec is introduced.
Hi Ming,
I've received a blktrace from our customer showing the issue [1].
In this example trace they've submitted (contiguous) 64K I/Os and
without this patch, they're seeing a lot of splits as indicated by the
trace.
With the patch applied the I/O is directly issued to the LLDD without
the splits.
[1] http://beta.suse.com/private/jthumshirn/blktrace.txt
Byte,
Johannes
--
Johannes Thumshirn SUSE Labs
jthumshirn@suse.de +49 911 74053 689
SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg
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next prev parent reply other threads:[~2018-11-06 12:34 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-05 10:23 Johannes Thumshirn
2018-11-05 10:55 ` Ming Lei
2018-11-05 11:50 ` Johannes Thumshirn
2018-11-05 12:01 ` Ming Lei
2018-11-06 12:34 ` Johannes Thumshirn [this message]
2018-11-06 14:56 ` Ming Lei
2018-11-06 15:14 ` Keith Busch
2018-11-07 3:14 ` Sagi Grimberg
2018-11-07 3:11 ` Sagi Grimberg
2018-11-06 14:31 ` Keith Busch
2018-11-06 14:53 ` Bart Van Assche
2018-11-06 14:56 ` Johannes Thumshirn
2018-11-07 3:30 ` Sagi Grimberg
2018-11-07 16:10 ` Bart Van Assche
2018-11-08 15:04 ` Christoph Hellwig
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