Date: Mon, 29 Sep 2003 09:29:06 +0930 From: Greg 'groggy' Lehey <grog@FreeBSD.org> To: Robert Watson <rwatson@FreeBSD.org> Cc: current@FreeBSD.org Subject: Re: HEADSUP: Change of makedev() semantics. Message-ID: <20030928235906.GG11520@wantadilla.lemis.com> In-Reply-To: <Pine.NEB.3.96L.1030928193949.20493L-100000@fledge.watson.org> References: <20030928230008.GF11520@wantadilla.lemis.com> <Pine.NEB.3.96L.1030928193949.20493L-100000@fledge.watson.org>
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--S5HS5MvDw4DmbRmb Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Sunday, 28 September 2003 at 19:46:20 -0400, Robert Watson wrote: > > On Mon, 29 Sep 2003, Greg 'groggy' Lehey wrote: > >> On Sunday, 28 September 2003 at 23:22:07 +0200, Poul-Henning Kamp wrote: >>> Basically: >>> >>> 3. If you do a "normal" device driver, cache the result >>> from when you call make_dev(). >>> ... >>> >>> ./dev/vinum >>> Failure to cache result of make_dev() ? >> >> Where should this be cached? Can you point to example code? > > Actually, it looks like Vinum is caching the dev_t's, Ah, you mean saving the results rather than calling make_dev() every time? Yes, it only calls make_dev() once for any device. > but it's not always using them to get back to the dev_t--sometimes > it's invoking makedev() instead. However, this appears to happen > only in the vinumrevive.c code, so I'm not sure if that's a property > of the cached reference being unavailable it looks like it should be > available in that context though. No, it should always be available. I was going to say "I don't see any references to make_dev() in vinumrevive.c, nor any references to makedev() at all", but I see that VINUM_SD includes both. > I.e., using sd->dev instead of VINUM_SD() -- it looks like there is > a valid (struct sd *) reference there to follow, so you can get to > the dev_t without doing a makedev(). Yes, this is a bug (and an indication of the dangers of using macros :-) I'll fix it. Greg -- See complete headers for address and phone numbers. NOTE: Due to the currently active Microsoft-based worms, I am limiting all incoming mail to 131,072 bytes. This is enough for normal mail, but not for large attachments. Please send these as URLs. --S5HS5MvDw4DmbRmb Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.0 (FreeBSD) iD8DBQE/d3XKIubykFB6QiMRAm5CAKCPLcOmXQlsNb4IVNsJz2Wx1ip2SQCfTBtE E5DAbhM6C3Lms7NO/7/bJn0= =SbzM -----END PGP SIGNATURE----- --S5HS5MvDw4DmbRmb--
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