From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755166AbaJGSzl (ORCPT ); Tue, 7 Oct 2014 14:55:41 -0400 Received: from mail-la0-f47.google.com ([209.85.215.47]:40896 "EHLO mail-la0-f47.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754939AbaJGSzj (ORCPT ); Tue, 7 Oct 2014 14:55:39 -0400 MIME-Version: 1.0 In-Reply-To: <20141007175503.GE31328@mtj.dyndns.org> References: <1412372683-2003-1-git-send-email-mcgrof@do-not-panic.com> <1412372683-2003-8-git-send-email-mcgrof@do-not-panic.com> <20141006201926.GF18303@htj.dyndns.org> <20141006203627.GZ14081@wotan.suse.de> <20141006210118.GG18303@htj.dyndns.org> <20141006231046.GD14081@wotan.suse.de> <20141007173404.GB31328@mtj.dyndns.org> <20141007175010.GH14081@wotan.suse.de> <20141007175503.GE31328@mtj.dyndns.org> From: "Luis R. Rodriguez" Date: Tue, 7 Oct 2014 11:55:16 -0700 X-Google-Sender-Auth: V-SkalPCHSOs3_soRpne2a4WHX8 Message-ID: Subject: Re: [PATCH v2 7/7] driver-core: add preferred async probe option for built-in and modules To: Tejun Heo Cc: Greg Kroah-Hartman , Dmitry Torokhov , Takashi Iwai , Arjan van de Ven , Tom Gundersen , Robert Milasan , werner@suse.com, Oleg Nesterov , hare , Benjamin Poirier , Santosh Rastapur , Petr Mladek , dbueso@suse.com, "linux-kernel@vger.kernel.org" , Tetsuo Handa , Joseph Salisbury , Kay Sievers , One Thousand Gnomes , Tim Gardner , Pierre Fersing , Andrew Morton , Nagalakshmi Nandigama , Praveen Krishnamoorthy , Sreekanth Reddy , Abhijit Mahajan , Casey Leedom , Hariprasad S , "mpt-fusionlinux.pdl" , Linux SCSI List , "netdev@vger.kernel.org" Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Oct 7, 2014 at 10:55 AM, Tejun Heo wrote: > Hello, > > On Tue, Oct 07, 2014 at 07:50:10PM +0200, Luis R. Rodriguez wrote: >> On Tue, Oct 07, 2014 at 01:34:04PM -0400, Tejun Heo wrote: >> > But you can create a new workqueue and queue all the async probing >> > work items there and flush the workqueue right after >> > async_synchronize_full(). >> >> On second thought I would prefer to avoid this, I see this being good >> to help with old userspace but other than that I don't see a requirement >> for new userspace. Do you? > > Hmmm... we batch up and do everything parallel, so I'm not sure how > much gain we'd be looking at by not waiting for at the end before > jumping into the userland. Also, it's a bit of an orthogonal issue. > If we wanna skip such synchornization point before passing control to > userland, why are we applying that to this but not > async_synchronize_full() which has a far larger impact? It's weird to > synchronize one while not the other, so yeah, if there are actual > benefits we can consider it but let's do it separately. OK I'll just kill bus.enable_kern_async=1 to enable built-in async probe support *and* also have prefer_async_probe *always* be respected, whether modular or not. Luis