From: Joe Thornber <thornber@redhat.com>
To: Dennis Yang <dennisyang@qnap.com>
Cc: device-mapper development <dm-devel@redhat.com>
Subject: Re: I/O block when removing thin device on the same pool
Date: Fri, 29 Jan 2016 16:05:16 +0000 [thread overview]
Message-ID: <20160129160515.GB23215@rh-vpn> (raw)
In-Reply-To: <CAAR726KUTU0Q-hYqXy7BZUke-qb7f_cbUJNrnrwdsiZLxXxLxA@mail.gmail.com>
On Fri, Jan 29, 2016 at 07:01:44PM +0800, Dennis Yang wrote:
> I had tried to define MAX_DECS as 1, 16, and 8192, and here is the
> throughput I got.
> When #define MAX_DECS 1, throughput drops from 3.2GB/s to around 800 ~ 950
> MB/s.
> When #define MAX_DECS 16, throughput drops from 3.2GB/s to around 150 ~ 400
> MB/s
> When #define MAX_DECS 8192, the I/O blocks until deletion is done.
>
> These throughput is gathered by writing to a newly created thin device
> which means lots of provisioning take place. So it seems that the more fine
> grained lock we use here results in the higher throughput. Is there any
> concern if I set MAX_DECS to 1 for production?
Does the time taken to remove the thin device change as you drop it to one?
- Joe
next prev parent reply other threads:[~2016-01-29 16:05 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-01-20 10:05 I/O block when removing thin device on the same pool Dennis Yang
2016-01-20 11:27 ` Zdenek Kabelac
2016-01-20 16:17 ` Dennis Yang
2016-01-21 17:33 ` Nikolay Borisov
2016-01-21 19:44 ` Mike Snitzer
2016-01-22 13:38 ` Lars Ellenberg
2016-01-22 13:58 ` Zdenek Kabelac
2016-01-22 16:07 ` Mike Snitzer
2016-01-22 16:43 ` Joe Thornber
2016-01-25 9:13 ` Dennis Yang
2016-01-26 16:19 ` Joe Thornber
2016-01-27 4:51 ` Dennis Yang
2016-01-28 10:44 ` Joe Thornber
2016-01-29 11:01 ` Dennis Yang
2016-01-29 16:05 ` Joe Thornber [this message]
2016-02-01 3:52 ` Dennis Yang
2016-01-29 14:50 ` Lars Ellenberg
2016-01-29 16:04 ` Joe Thornber
2016-02-01 17:40 ` Lars Ellenberg
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