From mboxrd@z Thu Jan 1 00:00:00 1970 From: James Bottomley Subject: Re: [patch 1/1] Switch ioctl functions of drivers/scsi/sg.c to unlocked_ioctl Date: Thu, 10 Jan 2008 13:03:48 -0600 Message-ID: <1199991828.3141.82.camel@localhost.localdomain> References: <20080110180529.GA32640@skl-net.de> <1199991298.3141.75.camel@localhost.localdomain> <20080110185944.GA1690@one.firstfloor.org> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Return-path: Received: from accolon.hansenpartnership.com ([76.243.235.52]:36895 "EHLO accolon.hansenpartnership.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756253AbYAJTD4 (ORCPT ); Thu, 10 Jan 2008 14:03:56 -0500 In-Reply-To: <20080110185944.GA1690@one.firstfloor.org> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: Andi Kleen Cc: Andre Noll , linux-scsi , linux-kernel , kernel-janitors@vger.kernel.org, Richard Knutsson On Thu, 2008-01-10 at 19:59 +0100, Andi Kleen wrote: > > Really, all this is doing is open coding what the ioctl handler is doing > > anyway, isn't it? in which case, why bother to change it at all? > > Because once it's open coded it is visible and can then be eliminated. > Does SCSI need the BKL at all? No, of course not ... it hasn't for ages, otherwise linux performance would be in the tank. If we require the BKL at all in the ioctl path it will be to protect the non-SCSI structures we have to use. Is there any guide to which structures in the kernel still require the BKL? > But perhaps for such a long ioctl handler it would be better to move > the lock/unlock_kernel()s into the individual case ...: statements; > then it could be eliminated step by step. James