From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 975BAC4363D for ; Wed, 23 Sep 2020 07:07:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4A1A9235FC for ; Wed, 23 Sep 2020 07:07:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726615AbgIWHHC (ORCPT ); Wed, 23 Sep 2020 03:07:02 -0400 Received: from muru.com ([72.249.23.125]:45172 "EHLO muru.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726550AbgIWHHC (ORCPT ); Wed, 23 Sep 2020 03:07:02 -0400 Received: from atomide.com (localhost [127.0.0.1]) by muru.com (Postfix) with ESMTPS id A797A80A0; Wed, 23 Sep 2020 07:07:04 +0000 (UTC) Date: Wed, 23 Sep 2020 10:07:58 +0300 From: Tony Lindgren To: Laurent Pinchart Cc: Tomi Valkeinen , Linux-OMAP Subject: Re: Slow booting on x15 Message-ID: <20200923070758.GT7101@atomide.com> References: <20200918155844.GH28436@pendragon.ideasonboard.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200918155844.GH28436@pendragon.ideasonboard.com> Precedence: bulk List-ID: X-Mailing-List: linux-omap@vger.kernel.org * Laurent Pinchart [200918 15:59]: > On Fri, Sep 18, 2020 at 06:25:02PM +0300, Tomi Valkeinen wrote: > > Hi, > > > > Has anyone noticed that booting would have slowed down in 5.8 and in 5.9-rcs? I'm booting x15 with > > my custom config builder, which uses omap2plus_defconfig as a base. I see: > > > > v5.7 > > [ 0.597765] cpuidle: using governor menu > > [ 0.793198] No ATAGs? > > > > [ 9.654611] Run /sbin/init as init process > > > > 5.8 > > [ 0.616660] cpuidle: using governor menu > > [ 4.439856] No ATAGs? > > > > [ 15.484710] Run /sbin/init as init process > > > > v5.9-rc5 > > [ 0.706165] cpuidle: using governor menu > > [ 6.761812] No ATAGs? > > > > [ 19.522536] Run /sbin/init as init process > > > > > > So v5.7 boots quickly, and init starts around 9.6 secs. 5.8 is much slower, and 5.9-rc5 even slower. > > I've tracked this down to device_link_add_missing_supplier_links() > taking about 40+ms to run, for every device added to the system. Given > the large number of devices, this adds up to 10s on v5.9-rc5, when > called during the initial of_platform_populate(). > > It doesn't seem there's a single culprit here (although I may have > missed it), "just" lots of walks through the whole device tree that end > up taking way too much time. I'm not planning to investigate this > further at this point. Hmm so do you have some commit that causes this slowness? In general, we should now be looking each device at module_init time only when configured in the dts. I guess it's possible we still have some extra walking of the whole device tree left but this sounds like a more generic issue though and not related to the omap dts conversion. Regards, Tony