On Thursday, January 31, 2002, at 08:52 AM, Andrew Gallatin wrote: I was playing around with NFS. Darwin seems to perform well as a server, but its performance leaves a lot to be desired as a client because it appears to crippled by a 4k read and write size limit. (verified w/tcpdump). I can reduce the size with mount_nfs, but I cannot increase it over 4K bsd/nfs/nfs_bio.c: 108 int 109 nfs_bioread(vp, uio, ioflag, cred, getpages) 110 register struct vnode *vp; ... 138 /*due to getblk/vm interractions, use vm page size or less values */ 139 biosize = min(vp->v_mount->mnt_stat.f_iosize, PAGE_SIZE); ... pagein/pageout paths do not have this limitation... By poor performnace, I mean that Darwin reads at 12MB/sec over a 2Gb/sec link. Tru64 and FreeBSD can both read at 50MB/sec. (this is from a file warm in the server's cache; no disk I/O). Darwin performs just as well as the competition when its the server... Any chance of this 4K limit being lifted? In order to enable larger read()/writes(), vnode_pageout() and following NFS functions will needs some tweaks... bsd/nfs/nfs_bio.c nfs_bioread 139 biosize = min(vp->v_mount->mnt_stat.f_iosize, PAGE_SIZE); bsd/nfs/nfs_bio.c nfs_write 543 biosize = min(vp->v_mount->mnt_stat.f_iosize, PAGE_SIZE); bsd/nfs/nfs_bio.c nfs_write 640 if (!ISSET(bp->b_flags, B_CACHE) && n < PAGE_SIZE) { bsd/nfs/nfs_bio.c nfs_write 645 auio.uio_resid = PAGE_SIZE; bsd/nfs/nfs_bio.c nfs_write 650 iov.iov_len = PAGE_SIZE; bsd/nfs/nfs_bio.c nfs_write 660 bp->b_validend = PAGE_SIZE - auio.uio_resid; bsd/nfs/nfs_bio.c nfs_write 663 PAGE_SIZE); bsd/nfs/nfs_bio.c nfs_getcacheblk 849 int biosize = min(vp->v_mount->mnt_stat.f_iosize, PAGE_SIZE); bsd/nfs/nfs_vfsops.c nfs_iosize 223 if (iosize < PAGE_SIZE) bsd/nfs/nfs_vfsops.c nfs_iosize 224 iosize = PAGE_SIZE; bsd/nfs/nfs_vnops.c nfs_setattr 974 PAGE_SIZE); bsd/nfs/nfs_vnops.c nfs_pageout 4402 lbn = f_offset / PAGE_SIZE; bsd/nfs/nfs_vnops.c nfs_pageout 4404 for (iosize = size; iosize > 0; iosize -= PAGE_SIZE, lbn++) { bsd/nfs/nfs_vnops.c nfs_pageout 4450 pgsize = (iosize + (PAGE_SIZE - 1)) & ~PAGE_MASK; bsd/nfs/nfs_vnops.c nfs_blktooff 4595 biosize = min(vp->v_mount->mnt_stat.f_iosize, PAGE_SIZE); bsd/nfs/nfs_vnops.c nfs_offtoblk 4613 biosize = min(vp->v_mount->mnt_stat.f_iosize, PAGE_SIZE); --Umesh -- Umesh Vaishampayan Mac OS X kernel group _______________________________________________ darwin-kernel mailing list | darwin-kernel@lists.apple.com Help/Unsubscribe/Archives: http://www.lists.apple.com/mailman/listinfo/darwin-kernel Do not post admin requests to the list. They will be ignored.