Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1762255Ab3ECCRE (ORCPT ); Thu, 2 May 2013 22:17:04 -0400 Received: from mail-vc0-f173.google.com ([209.85.220.173]:53248 "EHLO mail-vc0-f173.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760599Ab3ECCRA (ORCPT ); Thu, 2 May 2013 22:17:00 -0400 MIME-Version: 1.0 In-Reply-To: <20130503000358.GX19814@mtj.dyndns.org> References: <1367458508-9133-1-git-send-email-ccross@android.com> <1367458508-9133-4-git-send-email-ccross@android.com> <20130502235505.GW19814@mtj.dyndns.org> <20130503000358.GX19814@mtj.dyndns.org> Date: Thu, 2 May 2013 19:16:59 -0700 X-Google-Sender-Auth: 0rXgfmv36oI8jTI7mstFxKJLKjU Message-ID: Subject: Re: [PATCH v2 03/10] freezer: add new freezable helpers using freezer_do_not_count() From: Colin Cross To: Tejun Heo Cc: Linux PM list , lkml , "Rafael J. Wysocki" , =?ISO-8859-1?Q?Arve_Hj=F8nnev=E5g?= , Oleg Nesterov , Len Brown , Pavel Machek , Jeff Layton Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1474 Lines: 29 This sounds the same as what ended up getting reverted in https://lkml.org/lkml/2013/3/4/221 I can add the WARN_ON_ONCE to all my new calls, and leave them out of existing calls, but that seems a little odd, and will be redundant if the lockdep call in try_to_freeze goes back in in 3.11. Do you still want it in the new apis? On Thu, May 2, 2013 at 5:03 PM, Tejun Heo wrote: > On Thu, May 02, 2013 at 04:55:05PM -0700, Tejun Heo wrote: >> So, the freezable interface can't be something that people can use >> casually. It is something which should be carefully and strategically >> deployed where we *know* that lock dependency risks don't exist or at >> least are acceptable. I'm a bit weary that this patch is expanding >> the interface a lot that they now look like the equivalents of normal >> schedule calls. Not exactly sure what to do here but can we please at >> least have RED BOLD BLINKING comments which scream to people not to >> use these unless they know what they're doing? > > Maybe we should trigger WARN_ON_ONCE() if lockdep_depth() > 0 by > default and have ugly variants which can be used if the caller is sure > that it's okay possibly with list of locks which are held? > > -- > tejun -- 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/