Date: Fri, 17 Jul 1998 15:49:31 +0100 (BST) From: Mark Powell <M.S.Powell@ais.salford.ac.uk> To: freebsd-net@FreeBSD.ORG Subject: 2.2.6 net performance and panic with 1000's of sockets open Message-ID: <Pine.BSF.3.96.980717154849.1098A-100000@plato.salford.ac.uk>
next in thread | raw e-mail | index | archive | help
Been doing some stress testing of a web caching solutions, to see which is the better of squid-1.NOVM.22 running under 2.2.6-RELEASE or Novell's offering FastCache. My workstation and the cache box, being tested, both have Intel EtherExpress cards running at 100M into the same switch, so they get as near the full bandwidth as possible. I put FreeBSD on one disk and Netware 4.11 on another and just swapped the drives around at boot time to get the desired OS. Thus any hardware difference was ruled out. Knocked together a few small C programs. I noticed that the max throughput of the FreeBSD box was a shade over 6M/sec whilst the Netware box could manage up to nearly 9M/sec. I thought Netware may have the edge, but by that much? I tried bumping send/recvspace up to 64K one both boxes, but that only had a very slight performance increase. Is there anything else I could try? Using another test program I found that FreeBSD would panic. The program opened 1000 sockets to the squid box and requested a file from the web through each. The machine would panic with a page fault everytime I ran this program. The squid box would display something like "out of mbufs increase maxusers" and then panic a second or two later. Sometimes my workstation, which was running the test program, would also come down at the same time. I noticed if I killed off all the unnecesary processes on my workstation it wouldn't panic. A process waking up is finding some of it's memory missing? Both my workstation and the box under test are running up to date 2.2.6-RELEASE with maxusers set to 256. I followed the kernel debugging information from the handbook, but gdb still moaned about not finding some memory. Anyway here it is: /sys/compile/SQUID.TAG # gdb -k kernel.debug /var/crash/vmcore.3 GDB is free software and you are welcome to distribute copies of it under certain conditions; type "show copying" to see the conditions. There is absolutely no warranty for GDB; type "show warranty" for details. GDB 4.16 (i386-unknown-freebsd), Copyright 1996 Free Software Foundation, Inc... IdlePTD 1ff000 current pcb at 1e674c panic: page fault #0 boot (howto=789038597) at ../../kern/kern_shutdown.c:266 266 dumppcb.pcb_cr3 = rcr3(); (kgdb) bt #0 boot (howto=789038597) at ../../kern/kern_shutdown.c:266 Cannot access memory at address 0xefbffde0. (kgdb) where #0 boot (howto=789038597) at ../../kern/kern_shutdown.c:266 #1 0x20726f74 in ?? () #2 0xb91774 in ?? () Cannot access memory at address 0xfe8308. (kgdb) BTW The Netware box didn't fail under any of these stress conditions. TIA Mark Powell - System Administrator (UNIX) - Clifford Whitworth Building A.I.S., University of Salford, Salford, Manchester, UK. Tel: +44 161 295 5936 Fax: +44 161 295 5888 Email: M.S.Powell@ais.salfrd.ac.uk finger mark@ucsalf.ac.uk (for PGP key) NO SPAM please: Spell salford correctly to reply to me. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-net" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?Pine.BSF.3.96.980717154849.1098A-100000>