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=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable 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 A728EC35270 for ; Fri, 18 Dec 2020 22:03:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5983923BDB for ; Fri, 18 Dec 2020 22:03:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726254AbgLRWC6 (ORCPT ); Fri, 18 Dec 2020 17:02:58 -0500 Received: from mail.kernel.org ([198.145.29.99]:36186 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726239AbgLRWC6 (ORCPT ); Fri, 18 Dec 2020 17:02:58 -0500 Date: Fri, 18 Dec 2020 14:02:00 -0800 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1608328921; bh=fAnk2UmSqMrq+GnQnRGNlskacHwWWjkcjsuD/OdyKZs=; h=From:To:Subject:In-Reply-To:From; b=vIrez+v0hCXNfWsSnXQwoDHbtMoFROZH4hleKEWRHsGNJ0qUQkSOKWOTU8yRVAjeZ AvoTu7v/jlZe9RZSXFsujMONRzWRXDJ2M/NPUi0QrWUlWNSkmhFHcNoO8v1w61BiNI b9Gjbgar4HJc3F9MSoe4OHkbpT2Kd6cMvrlsSD28= From: Andrew Morton To: akpm@linux-foundation.org, edumazet@google.com, guantaol@google.com, khazhy@google.com, linux-mm@kvack.org, mm-commits@vger.kernel.org, soheil@google.com, torvalds@linux-foundation.org, willemb@google.com Subject: [patch 11/78] epoll: pull all code between fetch_events and send_event into the loop Message-ID: <20201218220200.vfpDV7gWz%akpm@linux-foundation.org> In-Reply-To: <20201218140046.497484741326828e5b5d46ec@linux-foundation.org> User-Agent: s-nail v14.8.16 Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org From: Soheil Hassas Yeganeh Subject: epoll: pull all code between fetch_events and send_event into the loop This is a no-op change which simplifies the follow up patches. Link: https://lkml.kernel.org/r/20201106231635.3528496-7-soheil.kdev@gmail.com Signed-off-by: Soheil Hassas Yeganeh Suggested-by: Linus Torvalds Reviewed-by: Eric Dumazet Reviewed-by: Willem de Bruijn Reviewed-by: Khazhismel Kumykov Cc: Guantao Liu Signed-off-by: Andrew Morton --- fs/eventpoll.c | 41 +++++++++++++++++++++-------------------- 1 file changed, 21 insertions(+), 20 deletions(-) --- a/fs/eventpoll.c~epoll-pull-all-code-between-fetch_events-and-send_event-into-the-loop +++ a/fs/eventpoll.c @@ -1774,14 +1774,14 @@ static int ep_poll(struct eventpoll *ep, } fetch_events: - eavail = ep_events_available(ep); - if (!eavail) - eavail = ep_busy_loop(ep, timed_out); + do { + eavail = ep_events_available(ep); + if (!eavail) + eavail = ep_busy_loop(ep, timed_out); - if (eavail) - goto send_events; + if (eavail) + goto send_events; - do { if (signal_pending(current)) return -EINTR; @@ -1830,21 +1830,22 @@ fetch_events: * carefully under lock, below. */ eavail = 1; - } while (0); - if (!list_empty_careful(&wait.entry)) { - write_lock_irq(&ep->lock); - /* - * If the thread timed out and is not on the wait queue, it - * means that the thread was woken up after its timeout expired - * before it could reacquire the lock. Thus, when wait.entry is - * empty, it needs to harvest events. - */ - if (timed_out) - eavail = list_empty(&wait.entry); - __remove_wait_queue(&ep->wq, &wait); - write_unlock_irq(&ep->lock); - } + if (!list_empty_careful(&wait.entry)) { + write_lock_irq(&ep->lock); + /* + * If the thread timed out and is not on the wait queue, + * it means that the thread was woken up after its + * timeout expired before it could reacquire the lock. + * Thus, when wait.entry is empty, it needs to harvest + * events. + */ + if (timed_out) + eavail = list_empty(&wait.entry); + __remove_wait_queue(&ep->wq, &wait); + write_unlock_irq(&ep->lock); + } + } while (0); send_events: /* _