From owner-dev-commits-src-branches@freebsd.org Fri Mar 19 18:42:39 2021 Return-Path: Delivered-To: dev-commits-src-branches@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id 7F0DC57F185; Fri, 19 Mar 2021 18:42:39 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from mxrelay.nyi.freebsd.org (mxrelay.nyi.freebsd.org [IPv6:2610:1c1:1:606c::19:3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "mxrelay.nyi.freebsd.org", Issuer "R3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4F2CSH3BK6z3hWx; Fri, 19 Mar 2021 18:42:39 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from gitrepo.freebsd.org (gitrepo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:5]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id 603A819FC7; Fri, 19 Mar 2021 18:42:39 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from gitrepo.freebsd.org ([127.0.1.44]) by gitrepo.freebsd.org (8.16.1/8.16.1) with ESMTP id 12JIgdHZ059635; Fri, 19 Mar 2021 18:42:39 GMT (envelope-from git@gitrepo.freebsd.org) Received: (from git@localhost) by gitrepo.freebsd.org (8.16.1/8.16.1/Submit) id 12JIgdwG059634; Fri, 19 Mar 2021 18:42:39 GMT (envelope-from git) Date: Fri, 19 Mar 2021 18:42:39 GMT Message-Id: <202103191842.12JIgdwG059634@gitrepo.freebsd.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-branches@FreeBSD.org From: Dmitry Chagin Subject: git: 0cb6fa6acc93 - stable/13 - linux: make timerfd_settime(2) set expirations count to zero MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Git-Committer: dchagin X-Git-Repository: src X-Git-Refname: refs/heads/stable/13 X-Git-Reftype: branch X-Git-Commit: 0cb6fa6acc93231242ef40e77518a9016ef4076a Auto-Submitted: auto-generated X-BeenThere: dev-commits-src-branches@freebsd.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: Commits to the stable branches of the FreeBSD src repository List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 19 Mar 2021 18:42:39 -0000 The branch stable/13 has been updated by dchagin: URL: https://cgit.FreeBSD.org/src/commit/?id=0cb6fa6acc93231242ef40e77518a9016ef4076a commit 0cb6fa6acc93231242ef40e77518a9016ef4076a Author: shu AuthorDate: 2021-02-03 16:51:45 +0000 Commit: Dmitry Chagin CommitDate: 2021-03-19 18:36:11 +0000 linux: make timerfd_settime(2) set expirations count to zero On Linux, read(2) from a timerfd file descriptor returns an unsigned 8-byte integer (uint64_t) containing the number of expirations that have occurred, if the timer has already expired one or more times since its settings were last modified using timerfd_settime(), or since the last successful read(2). That's to say, once we do a read or call timerfd_settime(), timer fd's expiration count should be zero. Some Linux applications create timerfd and add it to epoll with LT mode, when event comes, they do timerfd_settime instead of read to stop event source from trigger. On FreeBSD, timerfd_settime(2) didn't set the count to zero, which caused high CPU utilization. Submitted by: ankohuu_outlook.com (Shunchao Hu) Differential Revision: https://reviews.freebsd.org/D28231 (cherry picked from commit ae71b794cbed19e5e25effc3438720ad452ab87c) --- sys/compat/linux/linux_event.c | 1 + 1 file changed, 1 insertion(+) diff --git a/sys/compat/linux/linux_event.c b/sys/compat/linux/linux_event.c index dfb4588392cc..54f6b083adf3 100644 --- a/sys/compat/linux/linux_event.c +++ b/sys/compat/linux/linux_event.c @@ -981,6 +981,7 @@ linux_timerfd_settime(struct thread *td, struct linux_timerfd_settime_args *args linux_timerfd_curval(tfd, &ots); tfd->tfd_time = nts; + tfd->tfd_count = 0; if (timespecisset(&nts.it_value)) { linux_timerfd_clocktime(tfd, &cts); ts = nts.it_value;