From mboxrd@z Thu Jan  1 00:00:00 1970
From: "H. Peter Anvin" <hpa@zytor.com>
Subject: Re: devpts mounts too slowly
Date: Wed, 10 Jun 2009 13:51:25 -0700
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Cc: Ray Lee <ray-lk@madrabbit.org>, renton@renton.name,
	linux-kernel@vger.kernel.org,
	linux-fsdevel <linux-fsdevel@vger.kernel.org>
To: Andrew Morton <akpm@linux-foundation.org>
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Andrew Morton wrote:
> 
> hm, OK.
> 
> I've now mounted 15000 devpts's and still no slowdown is evident.

I ran my test script, mounting ramfs, with n=100000, and well, gave up
since it hadn't gotten any further than 57000 or so overnight.  At that
time each individual mount was taking several seconds.

Graphing the delays seem to indicate O(n^2) behavior.

umounts do not appear affected; each umount still take negible time.

	-hpa