Date: Wed, 30 Nov 2011 16:45:58 +0100 From: Baptiste Daroussin <bapt@freebsd.org> To: John Baldwin <jhb@freebsd.org> Cc: freebsd-current@freebsd.org, imp@freebsd.org Subject: Re: [patch] turning devctl into a "multiple openable" device Message-ID: <20111130154558.GA1621@azathoth.lan> In-Reply-To: <201111301005.11938.jhb@freebsd.org> References: <20111130124320.GA1449@azathoth.lan> <201111301005.11938.jhb@freebsd.org>
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--UlVJffcvxoiEqYs2 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed, Nov 30, 2011 at 10:05:11AM -0500, John Baldwin wrote: > On Wednesday, November 30, 2011 7:43:20 am Baptiste Daroussin wrote: > > Hi all, > >=20 > > With the help of cognet, I wrote a patch to turn devctl into a multiple= openable > > device, that mean that it will allow to open /dev/devctl in multiple pr= ograms, > > for example hald and everythings that want to receive notification from= the > > device won't need to depend on haveing devd running. > >=20 > > here is the patch:=20 > > http://people.freebsd.org/~bapt/devctl_multi_open.diff >=20 > Shouldn't devctl_queue_data_f() use the requested malloc() flags instead = of > hardcoding M_NOWAIT? you are right, I'll fix that. >=20 > Also, I know that it was an intentional design decisison by Warner to have > the multiplexing of devctl data done in userland via devd rather than in = the > kernel. (I think he envisioned devd providing a UNIX domain socket or so= me > such for other daemons to use to listen to events.) Have you asked him a= bout > this change? I haven't discussed this with him, I just CC him now to have his opinion. In fact for somecase I find useful to have useland application able to get notification from device without having devd running at all plus the devctl= (4) manpage says:=20 " This design allows only one reader for /dev/devctl. This is not desirabl= e in the long run, but will get a lot of hair out of this implementation. Maybe= we should make this device a clonable device." that's why I didn't first spoke to Warner about this, which has been a mist= ake sorry about that. regards, Bapt --UlVJffcvxoiEqYs2 Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.18 (FreeBSD) iEYEARECAAYFAk7WT7YACgkQ8kTtMUmk6EyHnwCfW2HegLplMqZg+jXgCd8BzEIl azMAnj1f6SZEzzZCONTDQy6KwggUPOSF =1sck -----END PGP SIGNATURE----- --UlVJffcvxoiEqYs2--
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