From nobody Tue Jun 28 00:56:46 2022 X-Original-To: bugs@mlmmj.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mlmmj.nyi.freebsd.org (Postfix) with ESMTP id 32470876446 for ; Tue, 28 Jun 2022 00:56:47 +0000 (UTC) (envelope-from bugzilla-noreply@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 4LX5lL3hS2z3C4C for ; Tue, 28 Jun 2022 00:56:46 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from kenobi.freebsd.org (kenobi.freebsd.org [IPv6:2610:1c1:1:606c::50:1d]) (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 5B8AB131FA for ; Tue, 28 Jun 2022 00:56:46 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from kenobi.freebsd.org ([127.0.1.5]) by kenobi.freebsd.org (8.15.2/8.15.2) with ESMTP id 25S0ukwp033121 for ; Tue, 28 Jun 2022 00:56:46 GMT (envelope-from bugzilla-noreply@freebsd.org) Received: (from www@localhost) by kenobi.freebsd.org (8.15.2/8.15.2/Submit) id 25S0uk8o033120 for bugs@FreeBSD.org; Tue, 28 Jun 2022 00:56:46 GMT (envelope-from bugzilla-noreply@freebsd.org) X-Authentication-Warning: kenobi.freebsd.org: www set sender to bugzilla-noreply@freebsd.org using -f From: bugzilla-noreply@freebsd.org To: bugs@FreeBSD.org Subject: [Bug 264867] kevent EVFILT_TIMER, timer expiration with twice the period Date: Tue, 28 Jun 2022 00:56:46 +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: 13.1-STABLE X-Bugzilla-Keywords: X-Bugzilla-Severity: Affects Only Me X-Bugzilla-Who: markj@FreeBSD.org X-Bugzilla-Status: Open X-Bugzilla-Resolution: X-Bugzilla-Priority: --- X-Bugzilla-Assigned-To: 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 List-Id: Bug reports List-Archive: https://lists.freebsd.org/archives/freebsd-bugs List-Help: List-Post: List-Subscribe: List-Unsubscribe: Sender: owner-freebsd-bugs@freebsd.org MIME-Version: 1.0 ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1656377806; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=KvJZdR2r0IiFzwSAZm6Nb7fQexeVrnXAjeXdRB8qWP0=; b=god0uYWP5Y1hVAQZ52ySji2fe/Xp7AGsfOYbIvMrB6g0cRMnpVSv7bZW1Jn7Ri6nP1uPuk HagvWmW3QR+lKyMoJLNQ4Fks+VEV3+UnHiOcEuUiR3Z54XDOLBh6kp45Qx+p3GCjKX2gcn fMr5Rh7RdK+MdwQcZTDUVVaNCpVo9gPfNtR++wxf6vEbdoMCB5FPOPav9QwQTUlywSJBNL l71lAOMJMYe8fVzrfK4YdA2gHrb8TmF3Bx1SSbim2p2X9JTNfsNZKxFGEIKHhv0KFOgrT6 4yJK0lITNnVsmhrqh2pwZazA6Wwszga8lrHSUL/wxWfQ5SKlU6O1BZuZPiPufg== ARC-Seal: i=1; s=dkim; d=freebsd.org; t=1656377806; a=rsa-sha256; cv=none; b=Hs2QqWtUPgyYNAoq/Z0XwpIn+R0KvRl7HXn9mQPDeGYHUVzMux/nWdoIJpYtcVvi/nzYWA 1xDk9Cz7bipHkG67Neqy6gnwqsRuf45EVsy8YgIDY5wpiMnJnUbumDLXd/qRGQBkoowdaD EYw6uY8dglB8a/zNX5hsYAvJegsRvp32Nhl3imCJeAFBO9FrQiEHYbpq/SN8HlnOQE1rr6 owcN7c1pzrZBOP4WQRZ54rR0ElN9XBO3E9hFROCp6tIj5/TQVVocee8Oh+a/YNYZ4/JEBL dcoOLXc2g0CQpL4htOgBxLx2MDri+8xQWIgn4LS7voiJTVNNlDdrAvZan3vZqA== ARC-Authentication-Results: i=1; mx1.freebsd.org; none X-ThisMailContainsUnwantedMimeParts: N https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D264867 --- Comment #3 from Mark Johnston --- I'm able to reproduce what looks like a similar problem on a different test system. In my case, the extra delay is always close to a multiple of 20ms = (the kqueue timer period). Usually 40ms or 60ms. It often occurs soon after the program starts up. It happens with or without setting the scheduling polic= y. I suspect the problem is related to some kind of race in the EVFILT_TIMER c= ode. If I add EV_ONESHOT to the event, the problem is not reproducible anymore.= In the test case, when kevent() returns the timer is still armed, and it's supposed to be reconfigured by the next kevent() call. --=20 You are receiving this mail because: You are the assignee for the bug.=