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,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 335E5C43387 for ; Thu, 3 Jan 2019 15:01:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id F37CE2070D for ; Thu, 3 Jan 2019 15:01:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732153AbfACPBi (ORCPT ); Thu, 3 Jan 2019 10:01:38 -0500 Received: from mx2.suse.de ([195.135.220.15]:33128 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1729611AbfACPBO (ORCPT ); Thu, 3 Jan 2019 10:01:14 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay1.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id DB716ADE2; Thu, 3 Jan 2019 15:01:12 +0000 (UTC) From: Roman Penyaev Cc: Roman Penyaev , Davidlohr Bueso , Jason Baron , Al Viro , Andrew Morton , Linus Torvalds , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v2 2/4] epoll: loosen irq safety in ep_poll_callback() Date: Thu, 3 Jan 2019 16:01:02 +0100 Message-Id: <20190103150104.17128-3-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 Callers of the ep_poll_callback() (all set of wake_up_*poll()) disable interrupts, so no need to save/restore irq flags. Signed-off-by: Roman Penyaev Cc: 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 | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/fs/eventpoll.c b/fs/eventpoll.c index 3627c2e07149..3c373a510f65 100644 --- a/fs/eventpoll.c +++ b/fs/eventpoll.c @@ -1124,13 +1124,18 @@ struct file *get_epoll_tfile_raw_ptr(struct file *file, int tfd, static int ep_poll_callback(wait_queue_entry_t *wait, unsigned mode, int sync, void *key) { int pwake = 0; - unsigned long flags; struct epitem *epi = ep_item_from_wait(wait); struct eventpoll *ep = epi->ep; __poll_t pollflags = key_to_poll(key); int ewake = 0; - spin_lock_irqsave(&ep->wq.lock, flags); + /* + * Called by irq context or interrupts are disabled by the wake_up_*poll + * callers. + */ + lockdep_assert_irqs_disabled(); + + spin_lock(&ep->wq.lock); ep_set_busy_poll_napi_id(epi); @@ -1207,7 +1212,7 @@ static int ep_poll_callback(wait_queue_entry_t *wait, unsigned mode, int sync, v pwake++; out_unlock: - spin_unlock_irqrestore(&ep->wq.lock, flags); + spin_unlock(&ep->wq.lock); /* We have to call this outside the lock */ if (pwake) -- 2.19.1