From owner-freebsd-bugs@freebsd.org Wed Mar 6 14:35:35 2019 Return-Path: Delivered-To: freebsd-bugs@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id D48E315193EF for ; Wed, 6 Mar 2019 14:35:34 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from mailman.ysv.freebsd.org (mailman.ysv.freebsd.org [IPv6:2001:1900:2254:206a::50:5]) by mx1.freebsd.org (Postfix) with ESMTP id 57E9E8F96A for ; Wed, 6 Mar 2019 14:35:34 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: by mailman.ysv.freebsd.org (Postfix) id 1C50815193EE; Wed, 6 Mar 2019 14:35:34 +0000 (UTC) Delivered-To: bugs@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 09E0815193ED for ; Wed, 6 Mar 2019 14:35:34 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from mxrelay.ysv.freebsd.org (mxrelay.ysv.freebsd.org [IPv6:2001:1900:2254:206a::19:3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) server-signature RSA-PSS (4096 bits) client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "mxrelay.ysv.freebsd.org", Issuer "Let's Encrypt Authority X3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 99D708F969 for ; Wed, 6 Mar 2019 14:35:33 +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 mxrelay.ysv.freebsd.org (Postfix) with ESMTPS id D7AA98391 for ; Wed, 6 Mar 2019 14:35:32 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from kenobi.freebsd.org ([127.0.1.118]) by kenobi.freebsd.org (8.15.2/8.15.2) with ESMTP id x26EZWwi026267 for ; Wed, 6 Mar 2019 14:35:32 GMT (envelope-from bugzilla-noreply@freebsd.org) Received: (from www@localhost) by kenobi.freebsd.org (8.15.2/8.15.2/Submit) id x26EZW7V026266 for bugs@FreeBSD.org; Wed, 6 Mar 2019 14:35:32 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 236233] Python multiprocessing is 4x slower with 11.2 compared to 11.0 kernel Date: Wed, 06 Mar 2019 14:35:31 +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: 11.2-RELEASE X-Bugzilla-Keywords: regression X-Bugzilla-Severity: Affects Only Me X-Bugzilla-Who: arichardson@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 MIME-Version: 1.0 X-BeenThere: freebsd-bugs@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Bug reports List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 06 Mar 2019 14:35:35 -0000 https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D236233 --- Comment #4 from Alex Richardson --- It is a virtual machine with an Intel CPU: CPU info from dmesg: Hyper-V Version: 0.0.0 [SP0] Features=3D0x870 PM Features=3D0x0 [C0] Features3=3D0x0 XEN: Hypervisor version 4.7 detected. CPU: Intel(R) Xeon(R) CPU E5-2670 0 @ 2.60GHz (2593.81-MHz K8-class CPU) Origin=3D"GenuineIntel" Id=3D0x206d6 Family=3D0x6 Model=3D0x2d Steppi= ng=3D6 =20 Features=3D0x17c3fbff Features2=3D0x80b82201 AMD Features=3D0x28100800 AMD Features2=3D0x1 Hypervisor: Origin =3D "Microsoft Hv" real memory =3D 118107406336 (112636 MB) avail memory =3D 114828369920 (109508 MB) Event timer "LAPIC" quality 100 ACPI APIC Table: FreeBSD/SMP: Multiprocessor System Detected: 32 CPUs FreeBSD/SMP: 2 package(s) x 16 core(s) It is kind of difficult to see which sycalls take longer before and after = but my guess is that it is related to semaphores since it is attempting to get = data from the subprocesses and it uses semaphores for synchronization. I'm not sure if there is an easy way to see what is taking longer. I'll see= if I can somehow get the information using DTrace. --=20 You are receiving this mail because: You are the assignee for the bug.=