From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752270Ab0IKUIq (ORCPT ); Sat, 11 Sep 2010 16:08:46 -0400 Received: from moutng.kundenserver.de ([212.227.126.171]:56170 "EHLO moutng.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751923Ab0IKUIp (ORCPT ); Sat, 11 Sep 2010 16:08:45 -0400 From: Arnd Bergmann To: Frederic Weisbecker Subject: Re: BKL status? Date: Sat, 11 Sep 2010 22:08:05 +0200 User-Agent: KMail/1.13.5 (Linux/2.6.36-rc3+; KDE/4.5.1; x86_64; ; ) Cc: Thomas Gleixner , John Kacur , Sam Ravnborg , Trond Myklebust , "J. Bruce Fields" , Mauro Carvalho Chehab , Jan Blunck , Hans Verkuil , linux-kernel@vger.kernel.org, David Miller References: <20100824134931.GA30883@merkur.ravnborg.org> <20100907132725.GB5375@nowhere> <201009071710.40669.arnd@arndb.de> In-Reply-To: <201009071710.40669.arnd@arndb.de> MIME-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Message-Id: <201009112208.06233.arnd@arndb.de> X-Provags-ID: V02:K0:jtJoUEIxVsCyoGRhP9lqfMIoyasmsSAnb2Xzukn+YB8 J5abuQIbUdIz9yg8/kWYkQCzb4XdPb6g8Rprlu2rcJBOkGwtri qWw5YP8AfzGRFArN33IaFPPMTaramifWx9cT9qPPiedkNHlEo3 79NzD1VECIPNDMEojWL6DvN8eDdifML6dlcZiWE4OJm7L1a5ZE QrVOky4X7iqNRM2gZR+BQ== Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tuesday 07 September 2010 17:10:40 Arnd Bergmann wrote: > > > - individual drivers > > We have two categories here. There are a large number of trivial > drivers where we can prove that the BKL can get replaced with a > private mutex, as my 'trivial' branch in g.k.o:bkl.git does. > > Then there are some modules that are actually hard to do, most > of them obsolete. Judging purely by the number of number of > lock_kernel() calls, which is somewhat misleading, the main > offenders are: > > drivers/{media,staging,usb/gadget,char/raw} > fs/{autofs,coda,hpfs,isofs,ncpfs,nfs,smbfs,udf,ufs} > net/{appletalk,ipx,irda,ax25} > > Out of these, we definitely need to fix v4l, isofs and nfs > to have a chance of disabling the BKL in a distro kernel. > But first things first, once fs/lockd is done, we are > at the point where all remaining BKL users are in modules. I have now taken care of most of the trivial ones in my git tree and rebased the series. The only bits that are left are those I didn't want to touch for some reason: arch/sparc: DaveM to look into it drivers/media/video: Frederic has a series drivers/gpu/drm/{i810,i830}: actually hard, can become BROKEN_ON_SMP fs/lockd: Trond and Bruce will take care, disabled for now fs/*/: interdependencies with the vfs series, can wait for one more release net/{appletalk,ipx,irda,ax25}: no idea how to do it, need someone to actually care. Many of the file systems should be fairly easy to do for someone who knows more about VFS than me. However: autofs, coda, hpfs, ncpfs, smbfs and ufs may end up not surviving the BKL removal unharmed and likely get removed or marked BROKEN_ON_SMP unless someone puts some serious work into them. isofs and udf look similar, but I suppose someone will do it after all. Frederic has managed to do it for Reiserfs, so I'm sure we will find a way to fix these. Arnd