From owner-freebsd-bugs@freebsd.org Sun May 19 16:11:45 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 2931515B1BD0 for ; Sun, 19 May 2019 16:11:45 +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 B2D206ADD1 for ; Sun, 19 May 2019 16:11:44 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: by mailman.ysv.freebsd.org (Postfix) id 6F65B15B1BCF; Sun, 19 May 2019 16:11:44 +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 5DFB215B1BCE for ; Sun, 19 May 2019 16:11:44 +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 EE8596ADC7 for ; Sun, 19 May 2019 16:11:43 +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 330A417728 for ; Sun, 19 May 2019 16:11:43 +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 x4JGBhQO064193 for ; Sun, 19 May 2019 16:11:43 GMT (envelope-from bugzilla-noreply@freebsd.org) Received: (from www@localhost) by kenobi.freebsd.org (8.15.2/8.15.2/Submit) id x4JGBhnx064192 for bugs@FreeBSD.org; Sun, 19 May 2019 16:11:43 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 219216] sched_bind() blocks if the entropy pool is starved Date: Sun, 19 May 2019 16:11:41 +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-STABLE X-Bugzilla-Keywords: X-Bugzilla-Severity: Affects Many People X-Bugzilla-Who: cem@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: 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: Sun, 19 May 2019 16:11:45 -0000 https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D219216 --- Comment #10 from Conrad Meyer --- rand_harvestq has had CPU reduced significantly in 12.x timeframe =E2=80=94= previously it was attempting to obtain far more entropy and far more often than it actually needed. This was in part due to conservative estimates (r338293) = and in part due to bugs in random read (r338292, r339492). r287023, r334450 may also be relevant. If you have a concurrent reader, rand_harvestq will fight it for the global Fortuna state mutex on head today (and spin while waiting). You are somewh= at saved by READ_RANDOM_UIO dropping the Fortuna lock every 4kB (PAGE_SIZE). I have a revision proposed to reduce this conflict further: https://people.freebsd.org/~cem/rand_harvestq.png https://reviews.freebsd.org/D20313 --=20 You are receiving this mail because: You are the assignee for the bug.=