From owner-freebsd-hackers@FreeBSD.ORG Sat May 9 11:51:37 2009 Return-Path: Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id B50EC1065672 for ; Sat, 9 May 2009 11:51:37 +0000 (UTC) (envelope-from lars@e.0x20.net) Received: from mail.0x20.net (mail.0x20.net [217.69.67.217]) by mx1.freebsd.org (Postfix) with ESMTP id 76D9A8FC17 for ; Sat, 9 May 2009 11:51:37 +0000 (UTC) (envelope-from lars@e.0x20.net) Received: by mail.0x20.net (Postfix, from userid 1002) id 255133A581; Sat, 9 May 2009 13:35:00 +0200 (CEST) Date: Sat, 9 May 2009 13:35:00 +0200 From: Lars Engels To: Ed Schouten Message-ID: <20090509113459.GD56667@e.0x20.net> References: <20090508214117.GY58540@hoeg.nl> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="i7F3eY7HS/tUJxUd" Content-Disposition: inline In-Reply-To: <20090508214117.GY58540@hoeg.nl> X-Editor: VIM - Vi IMproved 7.2 X-Operation-System: FreeBSD 5.5-RELEASE-p19 User-Agent: Mutt/1.5.19 (2009-01-05) X-Mailman-Approved-At: Sat, 09 May 2009 11:57:25 +0000 Cc: FreeBSD Hackers , jt@0xabadba.be, vasanth raonaik Subject: Re: concurrent sysctl implementation X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 09 May 2009 11:51:38 -0000 --i7F3eY7HS/tUJxUd Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Fri, May 08, 2009 at 11:41:17PM +0200, Ed Schouten wrote: > Hi, >=20 > * vasanth raonaik wrote: > > Hello Jt, > >=20 > > I am a newbee in this alias. I am having a very basic question. It woul= d be > > really good if you could give me some of this information. > > Could you please elaborate on what is the current architecture of sysctl > > implementation and How the concurrency would benefit us. >=20 > Right now sysctl is synchronized using the sysctl lock. The problem is > that certain sysctls just block for a very long time (especially some of > the GEOM ones). We also call sysctl when we execute new processes, to > obtain a random number for the stack protector. This means we have quite > a lot of contention on it. This lock needs to be there, because sysctls > can be added and removed on demand. Why is sysctl used to get a random number? Can't we get a different source for it? --i7F3eY7HS/tUJxUd Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.9 (FreeBSD) iEYEARECAAYFAkoFamMACgkQKc512sD3afgmLACfY9bwMdM+B8qWEvDPm2oEaaGe mxUAn3YSBnxkrHOkm+BSCBBdhP2PRQIw =mlf8 -----END PGP SIGNATURE----- --i7F3eY7HS/tUJxUd--