Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756186AbXENOb7 (ORCPT ); Mon, 14 May 2007 10:31:59 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754611AbXENObu (ORCPT ); Mon, 14 May 2007 10:31:50 -0400 Received: from hancock.steeleye.com ([71.30.118.248]:38750 "EHLO hancock.sc.steeleye.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1754532AbXENObt (ORCPT ); Mon, 14 May 2007 10:31:49 -0400 Subject: Re: why does x86 "make defconfig" build a single, lonely module? From: James Bottomley To: Satyam Sharma Cc: Dave Jones , "Robert P. J. Day" , Linux Kernel Mailing List , linux-scsi@vger.kernel.org In-Reply-To: References: <20070513160608.GA29024@redhat.com> <1179072655.3723.42.camel@mulgrave.il.steeleye.com> <1179073116.3723.45.camel@mulgrave.il.steeleye.com> Content-Type: text/plain Date: Mon, 14 May 2007 09:31:36 -0500 Message-Id: <1179153096.3703.23.camel@mulgrave.il.steeleye.com> Mime-Version: 1.0 X-Mailer: Evolution 2.8.3 (2.8.3-2.fc6) Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3384 Lines: 91 On Mon, 2007-05-14 at 17:53 +0530, Satyam Sharma wrote: > > I guess this is probably the behaviour that James wanted originally? No ... you're still not reading the explanation in the thread: The wait scan module is designed to wait for scans of driver modules. Whether SCSI=y or m has no effect on this ... you can still have modular drivers with built in SCSI. > > Anyway, attached patch (subsumes previous one) cleans up all this. > > Now, scsi_wait_scan is the only guy who controls waiting upon async > > scans to complete: > > > > If SCSI=n, SCSI_WAIT_SCAN=n, obviously. > > > > If SCSI=y, SCSI_WAIT_SCAN=y, so it gets built-in and is run at > > late_initcall. > > > > If SCSI=m, SCSI_WAIT_SCAN=m too and would hopefully be run > > by the initrd/initramfs scripts to wait for async SCSI bus scans to > > finish before allowing the boot to proceed. > > > > [ Attached patch does _not_ expose SCSI_WAIT_SCAN to the > > user at kernel configuration time, so if somebody wants it to be > > built as a module even when SCSI=y (why would anybody > > want that, doesn't make much sense to me to modprobe > > scsi_wait_scan _after_ boot-up), it would not be possible to > > do so. But if someone really wants that, let me know, we can > > add a depends, tristate "..." and help in this Kconfig option to > > accomplish that too. ] > > This has sadly become a one-person thread, but Robert informs > me in private mail that we can further clean/simplify the patch: > > [subsumes both previous patches] > > Signed-off-by: Satyam Sharma > > --- > > drivers/scsi/Kconfig | 3 +-- > drivers/scsi/scsi_scan.c | 5 +---- > 2 files changed, 2 insertions(+), 6 deletions(-) > > --- > > diff -ruNp a/drivers/scsi/Kconfig b/drivers/scsi/Kconfig > --- a/drivers/scsi/Kconfig 2007-05-10 23:19:32.000000000 +0530 > +++ b/drivers/scsi/Kconfig 2007-05-14 17:59:51.000000000 +0530 > @@ -243,9 +243,8 @@ config SCSI_SCAN_ASYNC > > config SCSI_WAIT_SCAN > tristate > - default m > depends on SCSI > - depends on MODULES > + default SCSI > > menu "SCSI Transports" > depends on SCSI > diff -ruNp a/drivers/scsi/scsi_scan.c b/drivers/scsi/scsi_scan.c > --- a/drivers/scsi/scsi_scan.c 2007-05-14 16:06:43.000000000 +0530 > +++ b/drivers/scsi/scsi_scan.c 2007-05-14 16:10:34.000000000 +0530 > @@ -184,14 +184,11 @@ int scsi_complete_async_scans(void) > /* Only exported for the benefit of scsi_wait_scan */ > EXPORT_SYMBOL_GPL(scsi_complete_async_scans); > > -#ifndef MODULE > /* > * For async scanning we need to wait for all the scans to complete before > * trying to mount the root fs. Otherwise non-modular drivers may not be ready > - * yet. > + * yet. This is done by scsi_wait_scan. > */ > -late_initcall(scsi_complete_async_scans); > -#endif This is actually not in mainline. It's an incorrect patch in -mm. The problem with late_initcall is that they queue in link order ... so any SCSI module (and there a few) linked after this won't benefit from it. The obvious hack is to have a separate file with this in the final link. However, Matthew Wilcox thinks he can do better. James - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/