From owner-freebsd-bugs@freebsd.org Thu Sep 19 14:56:09 2019 Return-Path: Delivered-To: freebsd-bugs@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 07B3412595F for ; Thu, 19 Sep 2019 14:56:09 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from mailman.nyi.freebsd.org (mailman.nyi.freebsd.org [IPv6:2610:1c1:1:606c::50:13]) by mx1.freebsd.org (Postfix) with ESMTP id 46Z0KN6WC1z3Lbw for ; Thu, 19 Sep 2019 14:56:08 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: by mailman.nyi.freebsd.org (Postfix) id DF7FC12595E; Thu, 19 Sep 2019 14:56:08 +0000 (UTC) Delivered-To: bugs@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 DF49E12595D for ; Thu, 19 Sep 2019 14:56:08 +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) server-signature RSA-PSS (4096 bits) client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "mxrelay.nyi.freebsd.org", Issuer "Let's Encrypt Authority X3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 46Z0KN5f9wz3Lbv for ; Thu, 19 Sep 2019 14:56:08 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from kenobi.freebsd.org (kenobi.freebsd.org [IPv6:2610:1c1:1:606c::50:1d]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id A58FBF1F5 for ; Thu, 19 Sep 2019 14:56:08 +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 x8JEu8VX097607 for ; Thu, 19 Sep 2019 14:56:08 GMT (envelope-from bugzilla-noreply@freebsd.org) Received: (from www@localhost) by kenobi.freebsd.org (8.15.2/8.15.2/Submit) id x8JEu8Ad097604 for bugs@FreeBSD.org; Thu, 19 Sep 2019 14:56:08 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 240687] jail cpuset masks cannot be expanded Date: Thu, 19 Sep 2019 14:56:08 +0000 X-Bugzilla-Reason: AssignedTo X-Bugzilla-Type: new X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: Base System X-Bugzilla-Component: kern X-Bugzilla-Version: CURRENT X-Bugzilla-Keywords: X-Bugzilla-Severity: Affects Some People X-Bugzilla-Who: jhb@FreeBSD.org X-Bugzilla-Status: New X-Bugzilla-Resolution: X-Bugzilla-Priority: --- X-Bugzilla-Assigned-To: bugs@FreeBSD.org X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: bug_id short_desc product version rep_platform op_sys bug_status bug_severity priority component assigned_to reporter Message-ID: 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: Thu, 19 Sep 2019 14:56:09 -0000 https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D240687 Bug ID: 240687 Summary: jail cpuset masks cannot be expanded Product: Base System Version: CURRENT Hardware: Any OS: Any Status: New Severity: Affects Some People Priority: --- Component: kern Assignee: bugs@FreeBSD.org Reporter: jhb@FreeBSD.org Suppose one creates a simple jail: jail -c name=3Dfoo command=3D/bin/sh It will inherit the default cpuset from the parent jail. You can use cpuse= t -j to shrink this set: % cpuset -g -j 1 jail 1 mask: 0, 1, 2, 3, 4, 5, 6, 7 % cpuset -g -j 1 -r jail 1 mask: 0, 1, 2, 3, 4, 5, 6, 7 % cpuset -j 1 -l 0-3 % cpuset -g -j 1 jail 1 mask: 0, 1, 2, 3 However, once you've shrunk the set, you can never expand it. The reason is that the jail set is its own root, so the check against the 'root' mask in cpuset_modify() fails with EINVAL. I think this is perhaps not the intended behavior. I think that when setting the cpuset of a jail you want to apply= the check against the parent jail's mask, not the jail's own mask. In particular, this prevents using cpuset -j to dynamically manage the CPUs available to jails. The alternative is to leave the jails unrestricted and manage the processes in the jail (or create dedicated, named cpusets for ea= ch jail and manage those) which is not as convenient for tools operating at the abstraction level of a jail. One possibility might be to have cpuset_getroot() always skip over the pass= ed in set to its parent at least once before checking for the ROOT flag (or fix callers to pass set->cs_parent instead of set), but I haven't looked at what other implications that might have. --=20 You are receiving this mail because: You are the assignee for the bug.=