Return-Path: Delivered-To: new-httpd-archive@hyperreal.org Received: (qmail 26424 invoked by uid 6000); 13 Nov 1997 14:04:34 -0000 Received: (qmail 26418 invoked from network); 13 Nov 1997 14:04:32 -0000 Received: from thoth.mch.sni.de (192.35.17.2) by taz.hyperreal.org with SMTP; 13 Nov 1997 14:04:32 -0000 Received: from deejai.mch.sni.de (deejai.mch.sni.de [139.25.113.10]) by thoth.mch.sni.de (8.8.8/8.8.8) with ESMTP id PAA19042 for ; Thu, 13 Nov 1997 15:04:29 +0100 (MET) Received: (from martin@localhost) by deejai.mch.sni.de (8.8.7/8.8.7) id PAA02893; Thu, 13 Nov 1997 15:04:26 +0100 (MET) Message-ID: <19971113150424.00353@deejai.mch.sni.de> Date: Thu, 13 Nov 1997 15:04:24 +0100 From: Martin Kraemer To: new-httpd@apache.org Subject: Re: Minimizing number of system calls? References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Mailer: Mutt 0.69 In-Reply-To: ; from Dean Gaudet on Wed, Nov 12, 1997 at 09:47:40PM -0800 Sender: new-httpd-owner@apache.org Precedence: bulk Reply-To: new-httpd@apache.org On Wed, Nov 12, 1997 at 09:47:40PM -0800, Dean Gaudet wrote: > I actually thought of another call I could remove, but the trick to do it > is escaping me right now ... I'll update the document next time it comes > back to me. I observed a number of redundant system calls on various SVR4 systems: depending on the setting of the TZ environment variable, _each_ call to gettimeofday() could cost three extra system calls: open("/usr/lib/locale/TZ/localtime", O_RDONLY, 0) = 3 read(3, "\0\0\0\0\0\0\0\0\0\0\0\0".., 7944) = 778 close(3) = 0 This happens only if the TZ variable uses the external time zone files (when you set TZ=:{timezone}, e.g., TZ=:MET), not when the SYSV syntax with the summer time algorithm included in the TZ setting is used (e.g., TZ="MET-1MDT,M3.5.0/02:00:00,M10.5.0/03:00:00"). I think we should warn users _somewhere_ that SVR4 performance can be slightly improved by setting the TZ variable right :-( Martin -- | S I E M E N S | | Siemens Nixdorf | ------------- | Voice: +49-89-636-46021 | Informationssysteme AG | N I X D O R F | FAX: +49-89-636-44994 | 81730 Munich, Germany ~~~~~~~~~~~~~~~~My opinions only, of course; pgp key available on request