From owner-cvs-all@FreeBSD.ORG Tue Mar 9 19:59:12 2004 Return-Path: Delivered-To: cvs-all@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id BEFF016A4CE; Tue, 9 Mar 2004 19:59:12 -0800 (PST) Received: from elvis.mu.org (elvis.mu.org [192.203.228.196]) by mx1.FreeBSD.org (Postfix) with ESMTP id A7A4943D31; Tue, 9 Mar 2004 19:59:12 -0800 (PST) (envelope-from bright@elvis.mu.org) Received: by elvis.mu.org (Postfix, from userid 1192) id A46B25C80F; Tue, 9 Mar 2004 19:59:12 -0800 (PST) Date: Tue, 9 Mar 2004 19:59:12 -0800 From: Alfred Perlstein To: Bruce Evans Message-ID: <20040310035912.GQ56622@elvis.mu.org> References: <200403090245.i292j0a6035728@repoman.freebsd.org> <20040309032248.GA88649@cat.robbins.dropbear.id.au> <20040309143223.Q234@freebsd3.cimlogic.com.au> <20040309035532.GA88825@cat.robbins.dropbear.id.au> <20040309150536.R234@freebsd3.cimlogic.com.au> <20040309043207.GA65153@kanpc.gte.com> <20040310000922.A5035@gamplex.bde.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20040310000922.A5035@gamplex.bde.org> User-Agent: Mutt/1.4.2.1i cc: src-committers@freebsd.org cc: cvs-src@freebsd.org cc: cvs-all@freebsd.org cc: John Birrell cc: Alexander Kabaev cc: Tim Robbins cc: John Birrell Subject: Re: cvs commit: src/lib/libc/stdio _flock_stub.c local.h X-BeenThere: cvs-all@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: CVS commit messages for the entire tree List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 10 Mar 2004 03:59:12 -0000 * Bruce Evans [040309 07:50] wrote: > On Mon, 8 Mar 2004, Alexander Kabaev wrote: > > > On Tue, Mar 09, 2004 at 03:05:36PM +1100, John Birrell wrote: > > > > > > I'm not sure that I agree that applications are 'broken' when they > > > use things that are defined in the header file along with the FILE > > > structure itself. > > It's a historical mistake that FILE is not opaque. > > > I would like to see FILE to become transparent to applications and its > > definition moved to the libc-private header file with the specific > > purpose of making the hack you mentioned impossible. > > This would pessimize even getc_unlocked() and putc_unlocked(). getc() > and putc() are now extern functions, but the old macro/inline versions > are still available as getc_unlocked() and putc_unlocked(). Simple > benchmarks for reading a 100MB file on an Athlon XP1600 overclocked > show that the function versions are up to 9 times slower: > > Time to read the file from a disk cache using read(): 0.17 seconds (sys) > getc_unlocked() overhead: 0.41 seconds (user) > getc() overhead: 1.64 seconds (user) > > This is with static linkage. Dynamic linkage increases the getc() > pessimization significantly: > > read() time: no significant change > getc_unlocked() overhead: 0.44 seconds (user) > getc() overhead: 3.62 seconds (user) Hmm, can't we use macros that do this: #define getc() (__isthreaded ? old_unlocked_code : getc_unlocked()) Where __isthreaded is a global that's set by threading libraries to 1 and 0 by non-threaded libc, this should get rid of a lot of the function call overhead. -- - Alfred Perlstein - Research Engineering Development Inc. - email: bright@mu.org cell: 408-480-4684