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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS autolearn=ham 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 08862C28CF6 for ; Wed, 1 Aug 2018 05:43:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B3AC4208A2 for ; Wed, 1 Aug 2018 05:43:16 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B3AC4208A2 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1733235AbeHAH1F (ORCPT ); Wed, 1 Aug 2018 03:27:05 -0400 Received: from mga12.intel.com ([192.55.52.136]:33441 "EHLO mga12.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1733161AbeHAH1F (ORCPT ); Wed, 1 Aug 2018 03:27:05 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga008.jf.intel.com ([10.7.209.65]) by fmsmga106.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 31 Jul 2018 22:43:14 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.51,430,1526367600"; d="scan'208";a="61430322" Received: from yhuang-dev.sh.intel.com (HELO yhuang-dev) ([10.239.13.118]) by orsmga008.jf.intel.com with ESMTP; 31 Jul 2018 22:43:11 -0700 From: "Huang\, Ying" To: Byungchul Park Cc: "Paul E. McKenney" , , , , , , , , , , , , , Subject: Re: [QUESTION] llist: Comment releasing 'must delete' restriction before traversing References: <1532998716-5037-1-git-send-email-byungchul.park@lge.com> <20180731043042.GJ24813@linux.vnet.ibm.com> <20180731092950.GB12241@X58A-UD3R> Date: Wed, 01 Aug 2018 13:43:10 +0800 In-Reply-To: <20180731092950.GB12241@X58A-UD3R> (Byungchul Park's message of "Tue, 31 Jul 2018 18:29:50 +0900") Message-ID: <878t5qabgx.fsf@yhuang-dev.intel.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/25.2 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=ascii Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Byungchul Park writes: > I think rcu list also works well. But I decided to use llist because > llist is simpler and has one less pointer. > > Just to be sure, let me explain my use case more: > > 1. Introduced a global list where single linked list is sufficient. > 2. All operations I need is to add items and traverse the list. > 3. Ensure the operations always happen within irq-disabled section. > 4. I'm considering CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG properly. > 5. The list can be accessed by every CPU concurrently. > Can you provide more information about where is your use case? Is it a kernel driver? Then it is better to submit the patch together with its user. And I have the similar concern as Steven Rostedt. That is, if you are the only user forever, it's not necessary to change the common code. Best Regards, Huang, Ying