<!-- MHonArc v2.4.4 --> <!--X-Subject: [MUD-Dev] Re: processors --> <!--X-From-R13: Brgev Hvexxhyn <civexxhyNvxv.sv> --> <!--X-Date: Sun, 31 Jan 1999 23:36:01 -0800 --> <!--X-Message-Id: 14005.22872.971767.715566#arioch,tky.hut.fi --> <!--X-Content-Type: text/plain --> <!--X-Reference: E106mSU-00051H-00#koala,kanga.nu --> <!--X-Reference: Pine.BSF.4.05.9901301831390.16840-100000#shell9,ba.best.com --> <!--X-Head-End--> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2//EN"> <html> <head> <title>MUD-Dev message, [MUD-Dev] Re: processors</title> <!-- meta name="robots" content="noindex,nofollow" --> <link rev="made" href="mailto:pvirkkul#iki,fi"> </head> <body background="/backgrounds/paperback.gif" bgcolor="#ffffff" text="#000000" link="#0000FF" alink="#FF0000" vlink="#006000"> <font size="+4" color="#804040"> <strong><em>MUD-Dev<br>mailing list archive</em></strong> </font> <br> [ <a href="../">Other Periods</a> | <a href="../../">Other mailing lists</a> | <a href="/search.php3">Search</a> ] <br clear=all><hr> <!--X-Body-Begin--> <!--X-User-Header--> <!--X-User-Header-End--> <!--X-TopPNI--> Date: [ <a href="msg00341.html">Previous</a> | <a href="msg00343.html">Next</a> ] Thread: [ <a href="msg00344.html">Previous</a> | <a href="msg00338.html">Next</a> ] Index: [ <A HREF="author.html#00342">Author</A> | <A HREF="#00342">Date</A> | <A HREF="thread.html#00342">Thread</A> ] <!--X-TopPNI-End--> <!--X-MsgBody--> <!--X-Subject-Header-Begin--> <H1>[MUD-Dev] Re: processors</H1> <HR> <!--X-Subject-Header-End--> <!--X-Head-of-Message--> <UL> <LI><em>To</em>: <A HREF="mailto:mud-dev#kanga,nu">mud-dev#kanga,nu</A></LI> <LI><em>Subject</em>: [MUD-Dev] Re: processors </LI> <LI><em>From</em>: Petri Virkkula <<A HREF="mailto:pvirkkul#iki,fi">pvirkkul#iki,fi</A>></LI> <LI><em>Date</em>: Mon, 1 Feb 1999 09:35:52 +0200 (EET)</LI> <LI><em>Reply-To</em>: <A HREF="mailto:mud-dev#kanga,nu">mud-dev#kanga,nu</A></LI> </UL> <!--X-Head-of-Message-End--> <!--X-Head-Body-Sep-Begin--> <HR> <!--X-Head-Body-Sep-End--> <!--X-Body-of-Message--> <PRE> >>>>> "Diablo" == <diablo#best,com> writes: Diablo> It's definitely not disk access. We barely access the disk at Diablo> all. Nearly everything is held in memory. Even if it looks so I think it would be wise to check your disk access patterns. An operating system can easily achieve 100% read cache hit rate (provided that there are enough memory in the machine) but write cache rates are usually very much lower. And surely you are writing atleast something to your disks? JC Lawrence gave us a good example, but here is another: BatMUD used to run on a machine that has 200MHz UltraSPARC CPU. All CPU power was used by the mud, but that could be handle by limit number of simultanous players. While the mud is not writing big quantities of data into a disk, it does very regurarily write something, for example logs are written, players are saving their character and so on. That did not cause much of problem, UNTIL another process accessed the same physical disk. For example a simple a grep, find etc. caused the mud to slow down noticeably, even lagging badly. What I gathered from statistics was that the mud and the grep or find were competing to get their turn to access the same physical disk. Not only that, the physical disk was read to/written from very different places, thus after every read/write disk head had to be moved to a correct place. And because disks have generally bad seek times, both processes (the mud and a grep for example) were waiting for completion of seek and read/write done by the other process. To solve the base problem (lack of CPU power) we decided to buy a new machine. But we also thought about the above I/O problem. One solution might have been to rewrite our game driver to use threads. That would have taken too much time, so we had to do something else. The solution to the I/O problem was to buy lots of memory, AND to buy four physical disks and to use disk mirroring. I am not sure how well that works, but atleast we thought that disk mirroring would make it possible for multiple processes to access a partition simultanously. Petri </PRE> <!--X-Body-of-Message-End--> <!--X-MsgBody-End--> <!--X-Follow-Ups--> <HR> <!--X-Follow-Ups-End--> <!--X-References--> <UL><LI><STRONG>References</STRONG>: <UL> <LI><STRONG><A NAME="00329" HREF="msg00329.html">[MUD-Dev] Re: processors</A></STRONG> <UL><LI><EM>From:</EM> J C Lawrence <claw#kanga,nu></LI></UL></LI> <LI><STRONG><A NAME="00331" HREF="msg00331.html">[MUD-Dev] Re: processors</A></STRONG> <UL><LI><EM>From:</EM> <diablo#best,com></LI></UL></LI> </UL></LI></UL> <!--X-References-End--> <!--X-BotPNI--> <UL> <LI>Prev by Date: <STRONG><A HREF="msg00341.html">[MUD-Dev] Re: processors</A></STRONG> </LI> <LI>Next by Date: <STRONG><A HREF="msg00343.html">[MUD-Dev] Re: processors</A></STRONG> </LI> <LI>Prev by thread: <STRONG><A HREF="msg00344.html">[MUD-Dev] Re: processors</A></STRONG> </LI> <LI>Next by thread: <STRONG><A HREF="msg00338.html">[MUD-Dev] Re: processors</A></STRONG> </LI> <LI>Index(es): <UL> <LI><A HREF="index.html#00342"><STRONG>Date</STRONG></A></LI> <LI><A HREF="thread.html#00342"><STRONG>Thread</STRONG></A></LI> </UL> </LI> </UL> <!--X-BotPNI-End--> <!--X-User-Footer--> <!--X-User-Footer-End--> <ul><li>Thread context: <BLOCKQUOTE><UL> <LI><STRONG>[MUD-Dev] Re: processors</STRONG>, <EM>(continued)</EM> <ul compact> <ul compact> <ul compact> <LI><strong><A NAME="00336" HREF="msg00336.html">[MUD-Dev] Re: processors</A></strong>, Mik Clarke <a href="mailto:mikclrk#ibm,net">mikclrk#ibm,net</a>, Sun 31 Jan 1999, 18:50 GMT </LI> <LI><strong><A NAME="00340" HREF="msg00340.html">[MUD-Dev] Re: processors</A></strong>, J C Lawrence <a href="mailto:claw#kanga,nu">claw#kanga,nu</a>, Mon 01 Feb 1999, 06:22 GMT <UL> <LI><strong><A NAME="00341" HREF="msg00341.html">[MUD-Dev] Re: processors</A></strong>, Marc Hernandez <a href="mailto:marc#ias,jb.com">marc#ias,jb.com</a>, Mon 01 Feb 1999, 07:08 GMT </LI> <LI><strong><A NAME="00344" HREF="msg00344.html">[MUD-Dev] Re: processors</A></strong>, Adam Wiggins <a href="mailto:adam#angel,com">adam#angel,com</a>, Mon 01 Feb 1999, 18:53 GMT </LI> </UL> </LI> <LI><strong><A NAME="00342" HREF="msg00342.html">[MUD-Dev] Re: processors</A></strong>, Petri Virkkula <a href="mailto:pvirkkul#iki,fi">pvirkkul#iki,fi</a>, Mon 01 Feb 1999, 07:36 GMT </LI> </ul> <LI><strong><A NAME="00338" HREF="msg00338.html">[MUD-Dev] Re: processors</A></strong>, Greg Underwood <a href="mailto:gunderwood#donet,com">gunderwood#donet,com</a>, Mon 01 Feb 1999, 02:15 GMT <UL> <LI><strong><A NAME="00343" HREF="msg00343.html">[MUD-Dev] Re: processors</A></strong>, Adam Wiggins <a href="mailto:adam#angel,com">adam#angel,com</a>, Mon 01 Feb 1999, 18:38 GMT </LI> </UL> </LI> </ul> </ul> </LI> <LI><strong><A NAME="00306" HREF="msg00306.html">[MUD-Dev] Re: Mud reviewing</A></strong>, Caliban Tiresias Darklock <a href="mailto:caliban#darklock,com">caliban#darklock,com</a>, Wed 27 Jan 1999, 16:10 GMT <UL> <LI><strong><A NAME="00316" HREF="msg00316.html">[MUD-Dev] Re: Mud reviewing</A></strong>, diablo <a href="mailto:diablo#best,com">diablo#best,com</a>, Wed 27 Jan 1999, 23:32 GMT </LI> </UL> </LI> </UL></BLOCKQUOTE> </ul> <hr> <center> [ <a href="../">Other Periods</a> | <a href="../../">Other mailing lists</a> | <a href="/search.php3">Search</a> ] </center> <hr> </body> </html>