From owner-freebsd-bugs@freebsd.org Fri May 12 11:29:21 2017 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 9484CD691D6 for ; Fri, 12 May 2017 11:29:21 +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 7668EE98 for ; Fri, 12 May 2017 11:29:21 +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 v4CBTJrK097070 for ; Fri, 12 May 2017 11:29:21 GMT (envelope-from bugzilla-noreply@freebsd.org) From: bugzilla-noreply@freebsd.org To: freebsd-bugs@FreeBSD.org Subject: [Bug 219216] sched_bind() blocks if the entropy pool is starved Date: Fri, 12 May 2017 11:29:19 +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: fk@fabiankeil.de 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: cc 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: Fri, 12 May 2017 11:29:21 -0000 https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D219216 Fabian Keil changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |fk@fabiankeil.de --- Comment #9 from Fabian Keil --- I can't reproduce the issue either. I'm using a kernel based on r318145: CPU: Intel(R) Core(TM) i5-2520M CPU @ 2.50GHz (2491.96-MHz K8-class CPU) I let the script run through 1680 cycles without noticeable issues. While dd keeps a core busy as expected, rand_harvestq stays below 3% cpu use according to top. I use vanilla powerd(8) which changes the cpu frequency between 800 and 2501. The fact that rand_harvestq is busy doesn't necessarily indicate that the entropy pool is starved. You could try running: sudo dtrace -n 'fbt:kernel:random_harvest_*:entry {@[probefunc, stack()] =3D count(); } tick-60sec {exit(0)}' to see which random_harvest_* functions are called, from where and how ofte= n. Additionally you could experiment with modifying the entropy sources with: kern.random.harvest.mask to see if it makes a difference. Newly harvested entropy is mixed into the pool so adding more shouldn't lower the "entropy quality" in the pool. Therefore it's not obvious to me h= ow the "poisoning" you mentioned would work. --=20 You are receiving this mail because: You are the assignee for the bug.=