From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751599AbdCBXB4 (ORCPT ); Thu, 2 Mar 2017 18:01:56 -0500 Received: from LGEAMRELO12.lge.com ([156.147.23.52]:43518 "EHLO lgeamrelo12.lge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751114AbdCBXBm (ORCPT ); Thu, 2 Mar 2017 18:01:42 -0500 X-Original-SENDERIP: 156.147.1.127 X-Original-MAILFROM: byungchul.park@lge.com X-Original-SENDERIP: 165.244.249.26 X-Original-MAILFROM: byungchul.park@lge.com X-Original-SENDERIP: 10.177.222.33 X-Original-MAILFROM: byungchul.park@lge.com Date: Fri, 3 Mar 2017 07:59:45 +0900 From: Byungchul Park To: , CC: , , , , , , , , , Subject: Re: [PATCH v3 1/9] llist: Provide a safe version for llist_for_each Message-ID: <20170302225945.GA28562@X58A-UD3R> References: <1487057190-25191-1-git-send-email-byungchul.park@lge.com> <1487057190-25191-2-git-send-email-byungchul.park@lge.com> <87r331fc5z.fsf@yhuang-dev.intel.com> MIME-Version: 1.0 In-Reply-To: <87r331fc5z.fsf@yhuang-dev.intel.com> User-Agent: Mutt/1.5.21 (2010-09-15) X-MIMETrack: Itemize by SMTP Server on LGEKRMHUB06/LGE/LG Group(Release 8.5.3FP6|November 21, 2013) at 2017/03/03 07:59:59, Serialize by Router on LGEKRMHUB06/LGE/LG Group(Release 8.5.3FP6|November 21, 2013) at 2017/03/03 07:59:59, Serialize complete at 2017/03/03 07:59:59 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Feb 14, 2017 at 03:45:44PM +0800, Huang, Ying wrote: > Byungchul Park writes: > > > Sometimes we have to dereference next field of llist node before entering > > loop becasue the node might be deleted or the next field might be > > modified within the loop. So this adds the safe version of llist_for_each, > > that is, llist_for_each_safe. > > > > Signed-off-by: Byungchul Park > > Reviewed-by: "Huang, Ying" Hello, Ingo and Peterz Does this have some problems? My 9th patch in this thread should be considered with this together. So could you check this? > > Best Regards, > Huang, Ying > > > --- > > include/linux/llist.h | 19 +++++++++++++++++++ > > 1 file changed, 19 insertions(+) > > > > diff --git a/include/linux/llist.h b/include/linux/llist.h > > index fd4ca0b..b90c9f2 100644 > > --- a/include/linux/llist.h > > +++ b/include/linux/llist.h > > @@ -105,6 +105,25 @@ static inline void init_llist_head(struct llist_head *list) > > for ((pos) = (node); pos; (pos) = (pos)->next) > > > > /** > > + * llist_for_each_safe - iterate over some deleted entries of a lock-less list > > + * safe against removal of list entry > > + * @pos: the &struct llist_node to use as a loop cursor > > + * @n: another &struct llist_node to use as temporary storage > > + * @node: the first entry of deleted list entries > > + * > > + * In general, some entries of the lock-less list can be traversed > > + * safely only after being deleted from list, so start with an entry > > + * instead of list head. > > + * > > + * If being used on entries deleted from lock-less list directly, the > > + * traverse order is from the newest to the oldest added entry. If > > + * you want to traverse from the oldest to the newest, you must > > + * reverse the order by yourself before traversing. > > + */ > > +#define llist_for_each_safe(pos, n, node) \ > > + for ((pos) = (node); (pos) && ((n) = (pos)->next, true); (pos) = (n)) > > + > > +/** > > * llist_for_each_entry - iterate over some deleted entries of lock-less list of given type > > * @pos: the type * to use as a loop cursor. > > * @node: the fist entry of deleted list entries.