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Date: Sat, 21 Jan 2017 20:13:06 +0200
From: Konstantin Belousov <kostikbel@gmail.com>
To: Ian Lepore <ian@freebsd.org>
Cc: Brooks Davis <brooks@FreeBSD.org>, src-committers@freebsd.org,
 svn-src-all@freebsd.org, svn-src-head@freebsd.org
Subject: Re: svn commit: r312588 - head/sys/mips/conf
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On Sat, Jan 21, 2017 at 10:50:54AM -0700, Ian Lepore wrote:
> On Sat, 2017-01-21 at 13:41 +0200, Konstantin Belousov wrote:
> > On Sat, Jan 21, 2017 at 09:08:28AM +0000, Brooks Davis wrote:
> > > 
> > > +optionsš	TMPFS			#Efficient memory
> > > filesystem
> > Is the word 'efficient' copied from somewhere ? Yes, I see it in
> > sys/conf/NOTES. I do not see what useful meaning the word has there,
> > applied to the tmpfs. In my opinion, it should be removed from
> > comments.
> > 
> 
> Is it not more efficient than the alternatives based on md(4)?

If UFS on a swap-backed md(4) is configured without SU and with trim
enabled, then it should be very similar to tmpfs.  Even more similar
if the UFS mount is sync.

Except in the case when the files from such mount are mmaped, in which
case UFS inherently performs double-copy.