NFS: support large reads and writes on the wire

Most NFS server implementations allow up to 64KB reads and writes on the
 wire.  The Solaris NFS server allows up to a megabyte, for instance.

 Now the Linux NFS client supports transfer sizes up to 1MB, too.  This will
 help reduce protocol and context switch overhead on read/write intensive NFS
 workloads, and support larger atomic read and write operations on servers
 that support them.

 Test-plan:
 Connectathon and iozone on mount point with wsize=rsize>32768 over TCP.
 Tests with NFS over UDP to verify the maximum RPC payload size cap.

 Signed-off-by: Chuck Lever <cel@netapp.com>
 Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This commit is contained in:
Chuck Lever 2005-11-30 18:09:02 -05:00 committed by Trond Myklebust
parent 325cfed9ae
commit 40859d7ee6
8 changed files with 91 additions and 53 deletions

View file

@ -221,10 +221,10 @@ nfs_calc_block_size(u64 tsize)
static inline unsigned long
nfs_block_size(unsigned long bsize, unsigned char *nrbitsp)
{
if (bsize < 1024)
bsize = NFS_DEF_FILE_IO_BUFFER_SIZE;
else if (bsize >= NFS_MAX_FILE_IO_BUFFER_SIZE)
bsize = NFS_MAX_FILE_IO_BUFFER_SIZE;
if (bsize < NFS_MIN_FILE_IO_SIZE)
bsize = NFS_DEF_FILE_IO_SIZE;
else if (bsize >= NFS_MAX_FILE_IO_SIZE)
bsize = NFS_MAX_FILE_IO_SIZE;
return nfs_block_bits(bsize, nrbitsp);
}
@ -307,20 +307,15 @@ nfs_sb_init(struct super_block *sb, rpc_authflavor_t authflavor)
max_rpc_payload = nfs_block_size(rpc_max_payload(server->client), NULL);
if (server->rsize > max_rpc_payload)
server->rsize = max_rpc_payload;
if (server->rsize > NFS_MAX_FILE_IO_SIZE)
server->rsize = NFS_MAX_FILE_IO_SIZE;
server->rpages = (server->rsize + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
if (server->wsize > max_rpc_payload)
server->wsize = max_rpc_payload;
server->rpages = (server->rsize + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
if (server->rpages > NFS_READ_MAXIOV) {
server->rpages = NFS_READ_MAXIOV;
server->rsize = server->rpages << PAGE_CACHE_SHIFT;
}
if (server->wsize > NFS_MAX_FILE_IO_SIZE)
server->wsize = NFS_MAX_FILE_IO_SIZE;
server->wpages = (server->wsize + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
if (server->wpages > NFS_WRITE_MAXIOV) {
server->wpages = NFS_WRITE_MAXIOV;
server->wsize = server->wpages << PAGE_CACHE_SHIFT;
}
if (sb->s_blocksize == 0)
sb->s_blocksize = nfs_block_bits(server->wsize,