From owner-freebsd-hackers Sun Dec 9 4:49:53 2001 Delivered-To: freebsd-hackers@freebsd.org Received: from bgzone.com (www.bgzone.com [217.79.65.49]) by hub.freebsd.org (Postfix) with ESMTP id 7D09C37B505 for ; Sun, 9 Dec 2001 04:49:28 -0800 (PST) Received: from earth.rila.bg (root@localhost [127.0.0.1]) by bgzone.com (8.9.3/8.9.3/SuSE Linux 8.9.3-0.1) with SMTP id QAA01727; Sun, 9 Dec 2001 16:49:12 +0200 Date: Sun, 9 Dec 2001 14:48:26 +0200 From: Dimitar Peikov To: Poul-Henning Kamp Cc: hackers@freebsd.org Subject: Re: Performance issue Message-Id: <20011209144826.557a6ff2.mitko@bgzone.com> In-Reply-To: <72360.1007898170@critter.freebsd.dk> References: <20011209125748.3d326e32.mitko@bgzone.com> <72360.1007898170@critter.freebsd.dk> Reply-To: mitko@rila.bg Organization: 4 Net X-Mailer: Sylpheed version 0.6.5 (GTK+ 1.2.10; i386--freebsd4.4) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG On Sun, 09 Dec 2001 12:42:50 +0100 Poul-Henning Kamp wrote: > > There are many effects that could cause this, for instance if FreeBSD > manages to align things differently in relation to the CPU cache you > could get some very interesting waste of time that way. Yes, I agree that in this case performance lost can be found in CPU Cache, but this can be true and when run on Linux, isn't it? > > Based on the data you show me, I can't really say that something is > wrong or right either way. Before I post this, I've got several experiments about that and the bottleneck was memory operations. The rest of my algorithm got near the same results. When perform only (malloc/free) operations without any touch of that allocated memory, there is no problem. The problem becames when you try to access it and only for the first memory hit. There is no mather if only one byte or whole memory block should be accessed, the difference is constantly the same. Or the problem is on all FreeBSD boxes installed near me? > > -- > Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 > phk@FreeBSD.ORG | TCP/IP since RFC 956 > FreeBSD committer | BSD since 4.3-tahoe > Never attribute to malice what can adequately be explained by incompetence. -- Dimitar Peikov Programmer Analyst Globalization Group "We Build e-Business" RILA Solutions 27 Building, Acad.G.Bonchev Str. 1113 Sofia, Bulgaria phone: (+359 2) 9797320 phone: (+359 2) 9797300 fax: (+359 2) 9733355 http://www.rila.com To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message