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From: Waiman Long <waiman.long@hp.com>
To: Dave Chinner <david@fromorbit.com>
Cc: Jason Low <jason.low2@hp.com>, Ingo Molnar <mingo@kernel.org>,
	Peter Zijlstra <peterz@infradead.org>,
	linux-kernel@vger.kernel.org, Davidlohr Bueso <davidlohr@hp.com>,
	Scott J Norton <scott.norton@hp.com>
Subject: Re: [PATCH 2/7] locking/rwsem: more aggressive use of optimistic spinning
Date: Mon, 18 Aug 2014 18:48:46 -0400	[thread overview]
Message-ID: <53F282CE.5030205@hp.com> (raw)
In-Reply-To: <20140817234152.GC26465@dastard>

On 08/17/2014 07:41 PM, Dave Chinner wrote:
> On Fri, Aug 15, 2014 at 01:58:09PM -0400, Waiman Long wrote:
>> On 08/14/2014 11:34 PM, Dave Chinner wrote:
>>> <create sparse vm image file of 500TB on ssd with XFS on it>
>>> xfs_io -f -c "truncate 500t" -c "extsize 1m" /path/to/vm/image/file
> ....
>> Thank for the testing recipe. I am afraid that I can't find a 500TB
>> SSD for testing purpose.
> Which bit of "sparse vm image file" didn't you understand?  I'm
> using a 400GB of SSD for this testing....
>
> $ df -h /mnt/fast-ssd
> Filesystem      Size  Used Avail Use% Mounted on
> /dev/sdf        400G  275G  125G  69% /mnt/fast-ssd
> $ ls -lh /mnt/fast-ssd/vm-500t.img
> -rw------- 1 root root 500T Aug 15 13:21 /mnt/fast-ssd/vm-500t.img
> $ du -sh /mnt/fast-ssd/vm-500t.img
> 275G    /mnt/fast-ssd/vm-500t.img
>
> That is on a Samsung 840 EVO SSD, which just about everyone should
> be able to obtain. Do you *really* think I have 500TB of SSDs lying
> around?
>
> Cheers,
>
> Dave.

I am sorry that I misunderstood your instruction. I am not a filesystem 
guy and haven't run this kind of test before.

Thank for the clarification.

-Longman

  reply	other threads:[~2014-08-18 22:48 UTC|newest]

Thread overview: 31+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-08-04  2:36 [PATCH 0/7] locking/rwsem: enable reader opt-spinning & writer respin Waiman Long
2014-08-04  2:36 ` [PATCH 1/7] locking/rwsem: don't resched at the end of optimistic spinning Waiman Long
2014-08-04  7:55   ` Peter Zijlstra
2014-08-04 18:36     ` Waiman Long
2014-08-04 20:48       ` Peter Zijlstra
2014-08-04 21:12         ` Jason Low
2014-08-05 17:54         ` Waiman Long
2014-08-04  2:36 ` [PATCH 2/7] locking/rwsem: more aggressive use " Waiman Long
2014-08-04  4:09   ` Davidlohr Bueso
2014-08-04  4:10   ` Jason Low
2014-08-04 15:44     ` Waiman Long
2014-08-13  5:51       ` Dave Chinner
2014-08-13 16:41         ` Waiman Long
2014-08-15  3:34           ` Dave Chinner
2014-08-15 17:58             ` Waiman Long
2014-08-16  7:40               ` Mike Galbraith
2014-08-17 23:41               ` Dave Chinner
2014-08-18 22:48                 ` Waiman Long [this message]
2014-08-04  2:36 ` [PATCH 3/7] locking/rwsem: check for active writer/spinner before wakeup Waiman Long
2014-08-04 21:20   ` Jason Low
2014-08-05 17:56     ` Waiman Long
2014-08-04  2:36 ` [PATCH 4/7] locking/rwsem: threshold limited spinning for active readers Waiman Long
2014-08-05  4:54   ` Davidlohr Bueso
2014-08-05  5:30     ` Davidlohr Bueso
2014-08-05  5:41       ` Davidlohr Bueso
2014-08-05 18:14     ` Waiman Long
2014-08-04  2:36 ` [PATCH 5/7] locking/rwsem: move down rwsem_down_read_failed function Waiman Long
2014-08-04  2:36 ` [PATCH 6/7] locking/rwsem: enables optimistic spinning for readers Waiman Long
2014-08-04  2:36 ` [PATCH 7/7] locking/rwsem: allow waiting writers to go back to optimistic spinning Waiman Long
2014-08-04  4:25 ` [PATCH 0/7] locking/rwsem: enable reader opt-spinning & writer respin Davidlohr Bueso
2014-08-04 18:07   ` Waiman Long

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