From owner-freebsd-bugs@freebsd.org Mon Dec 19 22:18:59 2016 Return-Path: Delivered-To: freebsd-bugs@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 8E075C8849C for ; Mon, 19 Dec 2016 22:18:59 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from kenobi.freebsd.org (kenobi.freebsd.org [IPv6:2001:1900:2254:206a::16:76]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 7E0A018FD for ; Mon, 19 Dec 2016 22:18:59 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from bugs.freebsd.org ([127.0.1.118]) by kenobi.freebsd.org (8.15.2/8.15.2) with ESMTP id uBJMIwHM037566 for ; Mon, 19 Dec 2016 22:18:59 GMT (envelope-from bugzilla-noreply@freebsd.org) From: bugzilla-noreply@freebsd.org To: freebsd-bugs@FreeBSD.org Subject: [Bug 214923] kqueue hangs with busy loop Date: Mon, 19 Dec 2016 22:18:59 +0000 X-Bugzilla-Reason: AssignedTo X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: Base System X-Bugzilla-Component: kern X-Bugzilla-Version: 11.0-RELEASE X-Bugzilla-Keywords: X-Bugzilla-Severity: Affects Only Me X-Bugzilla-Who: commit-hook@freebsd.org X-Bugzilla-Status: New X-Bugzilla-Resolution: X-Bugzilla-Priority: --- X-Bugzilla-Assigned-To: freebsd-bugs@FreeBSD.org X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: https://bugs.freebsd.org/bugzilla/ Auto-Submitted: auto-generated MIME-Version: 1.0 X-BeenThere: freebsd-bugs@freebsd.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Bug reports List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 19 Dec 2016 22:18:59 -0000 https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D214923 --- Comment #20 from commit-hook@freebsd.org --- A commit references this bug: Author: kib Date: Mon Dec 19 22:18:36 UTC 2016 New revision: 310302 URL: https://svnweb.freebsd.org/changeset/base/310302 Log: Do not clear KN_INFLUX when not owning influx state. For notes in KN_INFLUX|KN_SCAN state, the influx bit is set by a parallel scan. When knote() reports event for the vnode filters, which require kqueue unlocked, it unconditionally sets and then clears influx to keep note around kqueue unlock. There, do not clear influx flag if a scan set it, since we do not own it, instead we prevent scan from executing by holding knlist lock. The knote_fork() function has somewhat similar problem, it might set KN_INFLUX for scanned note, drop kqueue and list locks, and then clear the flag after relock. A solution there would be different enough, as well as the test program, so close the reported issue first. Reported and test case provided by: yjh0502@gmail.com PR: 214923 Tested by: pho Sponsored by: The FreeBSD Foundation MFC after: 1 week Changes: head/sys/kern/kern_event.c --=20 You are receiving this mail because: You are the assignee for the bug.=