From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from csamuel.org ([74.50.50.137]:39796 "EHLO csamuel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750756AbaCOGtE (ORCPT ); Sat, 15 Mar 2014 02:49:04 -0400 Received: from localhost (localhost [127.0.0.1]) by csamuel.org (Postfix) with ESMTP id E456ED47F1 for ; Sat, 15 Mar 2014 17:49:02 +1100 (EST) Received: from csamuel.org ([127.0.0.1]) by localhost (csamuel.org [127.0.0.1]) (amavisd-maia, port 10024) with LMTP id 23847-03 for ; Sat, 15 Mar 2014 17:49:02 +1100 (EST) Received: from quad.localnet (ppp59-167-127-196.static.internode.on.net [59.167.127.196]) by csamuel.org (Postfix) with ESMTPSA id 7CD80D47F0 for ; Sat, 15 Mar 2014 17:49:02 +1100 (EST) From: Chris Samuel To: linux-btrfs@vger.kernel.org Subject: Re: discard synchronous on most SSDs? Date: Sat, 15 Mar 2014 17:48:56 +1100 Message-ID: <1566234.HjNzCBAKa5@quad> In-Reply-To: <4448214.x9oPWjPhdL@quad> References: <1756989.4ep0Vdupld@tethys> <4448214.x9oPWjPhdL@quad> MIME-Version: 1.0 Content-Type: multipart/signed; boundary="nextPart30329158.UQJpz1ujyR"; micalg="pgp-sha1"; protocol="application/pgp-signature" Sender: linux-btrfs-owner@vger.kernel.org List-ID: --nextPart30329158.UQJpz1ujyR Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="us-ascii" On Sat, 15 Mar 2014 04:25:05 PM Chris Samuel wrote: > I wonder if it would be possible to use that knowledge to extend the=20= > smartctl's --identify functionality to report this? After reading the SATA 3.1 spec I believe that smartctl *can* indicate = if a=20 drive claims to support SATA 3.1 NCQ TRIM, thus: $ sudo smartctl --identify /dev/sdb | fgrep 'Trim bit in DATA SET MANAG= EMENT' 169 0 1 Trim bit in DATA SET MANAGEMENT command suppor= ted=20 $ If that command returns nothing then it's not reported as supported (an= d I've=20 tested that). You can get the same info with hdparm -I. Of course, as Martin said, that doesn't necessarily mean the kernel is = using=20 that reported ability. My puzzle now is that I have two SSD drives that report supporting NCQ = TRIM=20 (one confirmed via product info) but report only supporting SATA 3.0 no= t 3.1. cheers, Chris =2D-=20 Chris Samuel : http://www.csamuel.org/ : Melbourne, VIC --nextPart30329158.UQJpz1ujyR Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part. Content-Transfer-Encoding: 7Bit -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.14 (GNU/Linux) iQEVAwUAUyP32I1yjaOTJg85AQLWkAf/ZRinrYwI20UYClAyBskLLHDxZpibXwL8 BQuo1CHL9MUfHtrR0zUbQVm9UxKIgr3eEFuG6etixXsaIysiqdJgznyPipmiG/q1 gojoGQxr/FdPPYFWYpLmxbsQW9HTGbfFmwMuujTy87guuaANDVylDdoONDk8x9kd k99RJdqy+Hs0ob/Vqdcp8Lwln77ghBU1nvhFm9ow6YTb94FCkiZypMO3LaO7+DLO DPXej7wudN75j5ndT+mQglwi2BzG8x8lVBSgrvGVvDpV2jZXMEZXDJayzbrYb3bZ kx1AruMN9Cc25Bd735LtQNa3hFRBVH1ddoq/jHLLQpL9N8HjaHU8Eg== =Bg8Z -----END PGP SIGNATURE----- --nextPart30329158.UQJpz1ujyR--