From: Marc MERLIN <marc@merlins.org>
To: "Holger Hoffstätte" <holger.hoffstaette@googlemail.com>
Cc: linux-btrfs@vger.kernel.org
Subject: Re: discard synchronous on most SSDs?
Date: Fri, 14 Mar 2014 21:21:16 -0700 [thread overview]
Message-ID: <20140315042116.GK6143@merlins.org> (raw)
In-Reply-To: <pan.2014.03.14.20.46.24@googlemail.com>
On Fri, Mar 14, 2014 at 08:46:09PM +0000, Holger Hoffstätte wrote:
> On Fri, 14 Mar 2014 15:57:41 -0400, Martin K. Petersen wrote:
>
> > So right now I'm afraid we don't have a good way for a user to determine
> > whether a device supports queued trims or not.
>
> Mount with discard, unpack kernel tree, sync, rm -rf tree.
> If it takes several seconds, you have sync discard, no?
Mmmh, interesting point.
legolas:/usr/src# time rm -rf linux-3.14-rc5
real 0m1.584s
user 0m0.008s
sys 0m1.524s
I remounted my FS with remount,nodiscard, and the time was the same.
> This changed somewhere around kernel 3.8.x; before that it used to be
> acceptably fast. Since then I only do batch trims, daily (server) or
> weekly (laptop).
I'm never really timed this before. Is it supposed to be faster than 1.5s on
a fast SSD?
Marc
--
"A mouse is a device used to point at the xterm you want to type in" - A.S.R.
Microsoft is to operating systems ....
.... what McDonalds is to gourmet cooking
Home page: http://marc.merlins.org/
next prev parent reply other threads:[~2014-03-15 4:21 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-03-09 7:48 Massive BTRFS performance degradation KC
2014-03-09 8:17 ` Swâmi Petaramesh
2014-03-09 10:01 ` Martin Steigerwald
2014-03-09 10:23 ` Swâmi Petaramesh
2014-03-09 11:33 ` Hugo Mills
2014-03-09 11:54 ` Martin Steigerwald
2014-03-09 12:10 ` Swâmi Petaramesh
2014-03-09 17:14 ` boris
2014-03-14 2:11 ` discard synchronous on most SSDs? Marc MERLIN
2014-03-14 3:39 ` Chris Murphy
2014-03-14 5:17 ` Marc MERLIN
2014-03-14 7:33 ` Chris Samuel
2014-03-14 19:26 ` Marc MERLIN
2014-03-14 19:57 ` Martin K. Petersen
2014-03-14 20:46 ` Holger Hoffstätte
2014-03-15 4:21 ` Marc MERLIN [this message]
2014-03-15 9:38 ` Holger Hoffstätte
2014-03-15 5:25 ` Chris Samuel
2014-03-15 6:48 ` Chris Samuel
2014-03-15 11:26 ` Duncan
2014-03-15 22:48 ` Chris Samuel
2014-03-16 6:06 ` Marc MERLIN
2014-03-16 17:09 ` Chris Murphy
2014-03-16 16:22 ` Martin K. Petersen
2014-03-16 17:50 ` Marc MERLIN
2014-03-15 4:06 ` Chris Samuel
2014-03-16 16:07 ` Martin K. Petersen
2014-03-14 12:07 ` Duncan
2014-03-14 21:44 ` Chris Murphy
2014-03-14 7:27 ` Chris Samuel
2014-03-09 17:36 ` Massive BTRFS performance degradation Austin S Hemmelgarn
2014-03-09 18:55 ` Tobias Holst
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