From 4c8f7388e578751aab31ce0b8a982373a002aa7e Mon Sep 17 00:00:00 2001 From: dfr Date: Wed, 6 Nov 1996 10:53:16 +0000 Subject: Improve the queuing algorithms used by NFS' asynchronous i/o. The existing mechanism uses a global queue for some buffers and the vp->b_dirtyblkhd queue for others. This turns sequential writes into randomly ordered writes to the server, affecting both read and write performance. The existing mechanism also copes badly with hung servers, tending to block accesses to other servers when all the iods are waiting for a hung server. The new mechanism uses a queue for each mount point. All asynchronous i/o goes through this queue which preserves the ordering of requests. A simple mechanism ensures that the iods are shared out fairly between active mount points. This removes the sysctl variable vfs.nfs.dwrite since the new queueing mechanism removes the old delayed write code completely. This should go into the 2.2 branch. --- sys/nfsclient/nfsargs.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'sys/nfsclient/nfsargs.h') diff --git a/sys/nfsclient/nfsargs.h b/sys/nfsclient/nfsargs.h index 3d9d801..bc2edeb 100644 --- a/sys/nfsclient/nfsargs.h +++ b/sys/nfsclient/nfsargs.h @@ -34,7 +34,7 @@ * SUCH DAMAGE. * * @(#)nfs.h 8.1 (Berkeley) 6/10/93 - * $Id: nfs.h,v 1.17 1996/01/30 22:59:39 mpp Exp $ + * $Id: nfs.h,v 1.18 1996/08/21 21:55:44 dyson Exp $ */ #ifndef _NFS_NFS_H_ @@ -335,7 +335,7 @@ extern TAILQ_HEAD(nfs_reqq, nfsreq) nfs_reqq; #define NWDELAYHASH(sock, f) \ (&(sock)->ns_wdelayhashtbl[(*((u_long *)(f))) % NFS_WDELAYHASHSIZ]) #ifndef NFS_MUIDHASHSIZ -#define NFS_MUIDHASHSIZ 67 /* Tune the size of nfsmount with this */ +#define NFS_MUIDHASHSIZ 63 /* Tune the size of nfsmount with this */ #endif #define NMUIDHASH(nmp, uid) \ (&(nmp)->nm_uidhashtbl[(uid) % NFS_MUIDHASHSIZ]) -- cgit v1.1