From owner-freebsd-questions@FreeBSD.ORG Thu Apr 29 18:32:06 2010 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 70D081065672 for ; Thu, 29 Apr 2010 18:32:06 +0000 (UTC) (envelope-from joerg@mysql.com) Received: from gmp-eb-inf-2.sun.com (gmp-eb-inf-2.sun.com [192.18.6.24]) by mx1.freebsd.org (Postfix) with ESMTP id 03DB08FC14 for ; Thu, 29 Apr 2010 18:32:05 +0000 (UTC) Received: from fe-emea-13.sun.com (gmp-eb-lb-1-fe1.eu.sun.com [192.18.6.7] (may be forged)) by gmp-eb-inf-2.sun.com (8.13.7+Sun/8.12.9) with ESMTP id o3TIW4rp009453 for ; Thu, 29 Apr 2010 18:32:04 GMT MIME-version: 1.0 Content-type: text/plain; charset=ISO-8859-15 Received: from conversion-daemon.fe-emea-13.sun.com by fe-emea-13.sun.com (Sun Java(tm) System Messaging Server 7u2-7.04 64bit (built Jul 2 2009)) id <0L1N00500I51J700@fe-emea-13.sun.com> for freebsd-questions@freebsd.org; Thu, 29 Apr 2010 19:31:54 +0100 (BST) Received: from [129.150.117.250] ([unknown] [129.150.117.250]) by fe-emea-13.sun.com (Sun Java(tm) System Messaging Server 7u2-7.04 64bit (built Jul 2 2009)) with ESMTPSA id <0L1N0023FI54H070@fe-emea-13.sun.com>; Thu, 29 Apr 2010 19:31:54 +0100 (BST) Date: Thu, 29 Apr 2010 20:31:52 +0200 From: Joerg Bruehe Sender: Joerg.Bruehe@Sun.COM To: "Greg 'groggy' Lehey" , FreeBSD-Questions Message-id: <4BD9D098.8010201@mysql.com> Content-transfer-encoding: quoted-printable User-Agent: Thunderbird 2.0.0.23 (X11/20090817) Cc: Subject: Need info about FreeBSD and interrupted system calls for MySQL code X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 29 Apr 2010 18:32:06 -0000 Hi Groggy (whom I didn't contact for too long a time), everybody, following the advice on your page, I include the FreeBSD list, even though I'm not subscribed there (hoping it will allow me to post) - so please, whoever replies, could you please cc: me directly? Of course, I tried Google, but I didn't find any answers to my question. For some long, unknown time, the MySQL code contains a variable "net_retry_count" which is by default set to 10 (ten) for all platforms, but to 1000000 (1 million) for FreeBSD (during configure phase). The source code comment about this variable reads If a read on a communication port is interrupted, retry this many times before giving up. The documentation (manual) has this sentence in addition: This value should be set quite high on FreeBSD because internal interrupts are sent to all threads. I read that as "On FreeBSD, a thread may receive many more interrupts than on other platforms, so an operation which may take some time (like network I/O) may be interrupted much more often than on other platforms, and hence the retry count should be higher." I trust that this comment was valid at the time it was written - is it still true for current versions of FreeBSD, or did things change? Thanks for all your hints, J=F6rg --=20 Joerg Bruehe, MySQL Build Team, Joerg.Bruehe@Sun.COM (+49 30) 417 01 487 Sun Microsystems GmbH, Komturstrasse 18a, D-12099 Berlin Geschaeftsfuehrer: Juergen Kunz Amtsgericht Muenchen: HRB161028