Date: Wed, 8 Dec 2010 23:33:27 +0100 From: Pawel Jakub Dawidek <pjd@FreeBSD.org> To: Kirk McKusick <mckusick@mckusick.com> Cc: freebsd-fs@freebsd.org, Oliver Fromme <olli@lurza.secnetix.de> Subject: Re: TRIM support for UFS? Message-ID: <20101208223327.GD1884@garage.freebsd.pl> In-Reply-To: <201012082223.oB8MNqGV020879@chez.mckusick.com> References: <20101208214909.GH33073@deviant.kiev.zoral.com.ua> <201012082223.oB8MNqGV020879@chez.mckusick.com>
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--JwB53PgKC5A7+0Ej Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed, Dec 08, 2010 at 02:23:52PM -0800, Kirk McKusick wrote: > The above patch looks good though I would do it unconditionally > (e.g., also for snapshots). It seems sensible to make it conditional > on a sysctl variable so that folks could experiment with it more > easily. And I would leave it off by default as non-SSD disks are > unlikely to benefit from it. If it does prove useful for SSD disks > then I would make it conditional on a filesystem flag so that it > is possible to enable it on a filesystem-by-filesystem basis (e.g., > on for filesystems on the SSD and off for the rest). We already have a flag for disks: DISKFLAG_CANDELETE, which tells if the disk support TRIM or not. Next we should add BIO_GETATTR attribute for DISK class to return true if TRIM is supported. This way UFS can ask if TRIM is supported on mount and don't bother sending BIO_DELETE if it is not supported. --=20 Pawel Jakub Dawidek http://www.wheelsystems.com pjd@FreeBSD.org http://www.FreeBSD.org FreeBSD committer Am I Evil? Yes, I Am! --JwB53PgKC5A7+0Ej Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.14 (FreeBSD) iEYEARECAAYFAk0AB7YACgkQForvXbEpPzShTQCdEkP+WCZcl+x7DX2SP/RsxdRH WboAoOAHVCwYe1VMjxRZQcY8ZKrw8vkI =TvTM -----END PGP SIGNATURE----- --JwB53PgKC5A7+0Ej--
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