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=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT 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 149EFC43387 for ; Thu, 3 Jan 2019 15:01:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E15BF20815 for ; Thu, 3 Jan 2019 15:01:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732104AbfACPBO (ORCPT ); Thu, 3 Jan 2019 10:01:14 -0500 Received: from mx2.suse.de ([195.135.220.15]:33112 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1729306AbfACPBO (ORCPT ); Thu, 3 Jan 2019 10:01:14 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 87136ADBD; Thu, 3 Jan 2019 15:01:12 +0000 (UTC) From: Roman Penyaev Cc: Roman Penyaev , Jason Baron , Al Viro , Andrew Morton , Linus Torvalds , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v2 1/4] epoll: make sure all elements in ready list are in FIFO order Date: Thu, 3 Jan 2019 16:01:01 +0100 Message-Id: <20190103150104.17128-2-rpenyaev@suse.de> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20190103150104.17128-1-rpenyaev@suse.de> References: <20190103150104.17128-1-rpenyaev@suse.de> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit To: unlisted-recipients:; (no To-header on input) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org All coming events are stored in FIFO order and this is also should be applicable to ->ovflist, which originally is stack, i.e. LIFO. Thus to keep correct FIFO order ->ovflist should reversed by adding elements to the head of the read list but not to the tail. Signed-off-by: Roman Penyaev Reviewed-by: Davidlohr Bueso Cc: Jason Baron Cc: Al Viro Cc: Andrew Morton Cc: Linus Torvalds Cc: linux-fsdevel@vger.kernel.org Cc: linux-kernel@vger.kernel.org --- fs/eventpoll.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/fs/eventpoll.c b/fs/eventpoll.c index 2329f96469e2..3627c2e07149 100644 --- a/fs/eventpoll.c +++ b/fs/eventpoll.c @@ -722,7 +722,11 @@ static __poll_t ep_scan_ready_list(struct eventpoll *ep, * contain them, and the list_splice() below takes care of them. */ if (!ep_is_linked(epi)) { - list_add_tail(&epi->rdllink, &ep->rdllist); + /* + * ->ovflist is LIFO, so we have to reverse it in order + * to keep in FIFO. + */ + list_add(&epi->rdllink, &ep->rdllist); ep_pm_stay_awake(epi); } } -- 2.19.1