From: Benjamin LaHaise Subject: Re: huge number of intr/s on large nfs server Date: Thu, 17 Oct 2002 22:05:43 -0400 Sender: nfs-admin@lists.sourceforge.net Message-ID: <20021017220543.C3702@redhat.com> References: <20021016222854.C27038@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: nfs@lists.sourceforge.net Return-path: Received: from to-velocet.redhat.com ([216.138.202.10] helo=touchme.toronto.redhat.com) by usw-sf-list1.sourceforge.net with esmtp (Exim 3.31-VA-mm2 #1 (Debian)) id 182MWH-0002qD-00 for ; Thu, 17 Oct 2002 19:05:45 -0700 To: Eff Norwood In-Reply-To: ; from enorwood@effrem.com on Wed, Oct 16, 2002 at 07:49:38PM -0700 Errors-To: nfs-admin@lists.sourceforge.net List-Help: List-Post: List-Subscribe: , List-Id: Discussion of NFS under Linux development, interoperability, and testing. List-Unsubscribe: , List-Archive: On Wed, Oct 16, 2002 at 07:49:38PM -0700, Eff Norwood wrote: > This system in question is a SuperMicro P4DL6 MB with dual Xeon 2.4's and > 2.0GB of memory. One of the PCI-X slots/busses has a 3ware 7850 IDE RAID Can you try running a non-SMP kernel? At least one nfs server I'm running does pretty well with a UP kernel, even though it is getting in the neighbourhood of 10-20k interrupts per second. Note that it is using async writes, and gets about 40MB/s with ext3 and is 100% busy when being written to, with the bulk of the time spent computing raid checksum blocks and copying data around and in prune_icache. With an SMP system, there is likely to be contention introduced by interrupts floating back and forth between CPUs when the single client writing case is really not helped by SMP in the current knfsd. Binding various interrupts to specific CPUs may help things here, but part of the problem lies with knfsd allowing multiple processes to back up in generic_file_write, which serializes on the inode semaphore. This is pure overhead that a UP system won't suffer from quite as dramatically. Also, make sure your journal is on a separate disk. Cheers, -ben ------------------------------------------------------- This sf.net email is sponsored by: viaVerio will pay you up to $1,000 for every account that you consolidate with us. http://ad.doubleclick.net/clk;4749864;7604308;v? http://www.viaverio.com/consolidator/osdn.cfm _______________________________________________ NFS maillist - NFS@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/nfs