From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Date: Tue, 24 Jun 2008 09:39:51 -0400 From: Alan Cox To: Laurent Pinchart Message-ID: <20080624133951.GA9910@devserv.devel.redhat.com> References: <485F7A42.8020605@vidsoft.de> <200806240033.41145.laurent.pinchart@skynet.be> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200806240033.41145.laurent.pinchart@skynet.be> Cc: video4linux-list@redhat.com, linux-uvc-devel@lists.berlios.de Subject: Re: [Linux-uvc-devel] Thread safety of ioctls List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: video4linux-list-bounces@redhat.com Errors-To: video4linux-list-bounces@redhat.com List-ID: On Tue, Jun 24, 2008 at 12:33:40AM +0200, Laurent Pinchart wrote: > Not really. The ioctl handler is protected by the big kernel lock, so ioctls > are currently not reentrant. Not so - the BKL drops on sleeping so any ioctl that sleeps is re-entrant. Any code using locks of its own should be dropping their lock before any long sleeps. > Most drivers are probably not designed with thread safety in mind, and I'm > pretty sure lots of race conditions still lie in the depth of V4L(2) drivers. >>From looking at the BKL dropping work that would unfortunately seem to be the case for some drivers -- video4linux-list mailing list Unsubscribe mailto:video4linux-list-request@redhat.com?subject=unsubscribe https://www.redhat.com/mailman/listinfo/video4linux-list