From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753937Ab2LLJnO (ORCPT ); Wed, 12 Dec 2012 04:43:14 -0500 Received: from smtp.eu.citrix.com ([46.33.159.39]:6113 "EHLO SMTP.EU.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753462Ab2LLJnM (ORCPT ); Wed, 12 Dec 2012 04:43:12 -0500 X-IronPort-AV: E=Sophos;i="4.84,265,1355097600"; d="scan'208";a="81333" Message-ID: <50C84F2F.4080302@citrix.com> Date: Wed, 12 Dec 2012 10:32:31 +0100 From: =?UTF-8?B?Um9nZXIgUGF1IE1vbm7DqQ==?= User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.7; rv:17.0) Gecko/17.0 Thunderbird/17.0 MIME-Version: 1.0 To: Huang Ying CC: "linux-kernel@vger.kernel.org" , Konrad Rzeszutek Wilk Subject: Re: [PATCH v3] llist: add a safe version of llist_for_each_entry References: <1355187084.7216.102.camel@yhuang-dev> <1355225157-23609-1-git-send-email-roger.pau@citrix.com> <1355272642.7216.144.camel@yhuang-dev> In-Reply-To: <1355272642.7216.144.camel@yhuang-dev> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 12/12/12 01:37, Huang Ying wrote: > On Tue, 2012-12-11 at 12:25 +0100, Roger Pau Monne wrote: >> Signed-off-by: Roger Pau Monné >> Cc: Huang Ying >> Cc: Konrad Rzeszutek Wilk >> --- >> Changes since v2: >> * Allow to pass a NULL node as the first entry of deleted list >> entries. >> --- >> include/linux/llist.h | 27 +++++++++++++++++++++++++++ >> 1 files changed, 27 insertions(+), 0 deletions(-) >> >> diff --git a/include/linux/llist.h b/include/linux/llist.h >> index a5199f6..4e0aec1 100644 >> --- a/include/linux/llist.h >> +++ b/include/linux/llist.h >> @@ -125,6 +125,33 @@ static inline void init_llist_head(struct llist_head *list) >> (pos) = llist_entry((pos)->member.next, typeof(*(pos)), member)) >> >> /** >> + * llist_for_each_entry_safe - safely iterate over some deleted entries of >> + * lock-less list of given type >> + * @pos: the type * to use as a loop cursor. >> + * @n: the &struct llist_node to use as a temporary loop cursor > > In list_for_each_entry_safe, n is type *, why not follow that? Thanks for the review, yes I just saw it, I was using llist_node because I didn't need a type *, but I agree that it's best to stick with list_for_each_entry_safe interface. Will send v4.... > > Best Regards, > Huang Ying > >> + * @node: the fist entry of deleted list entries. >> + * @member: the name of the llist_node with the struct. >> + * >> + * In general, some entries of the lock-less list can be traversed >> + * safely only after being removed 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. >> + * >> + * n is used to store a reference to the next item llist_node, so >> + * pos can be freed while iterating. >> + */ >> +#define llist_for_each_entry_safe(pos, n, node, member) \ >> + for ((pos) = llist_entry((node), typeof(*(pos)), member), \ >> + (n) = (&(pos)->member != NULL) ? (pos)->member.next : NULL;\ >> + &(pos)->member != NULL; \ >> + (pos) = llist_entry(n, typeof(*(pos)), member), \ >> + (n) = (&(pos)->member != NULL) ? (pos)->member.next : NULL) >> + >> +/** >> * llist_empty - tests whether a lock-less list is empty >> * @head: the list to test >> * > >