documentation: note cxgb3 fw limitation

This patch describes a limitation of the Chelsio's T3 RNIC firmware that
causes issues with NFS-RDMA.

Signed-Off-By: Jon Mason <jon@opengridcomputing.com>

diff --git a/cxgb3_release_notes.txt b/cxgb3_release_notes.txt
index dcfbe3e205e9672f5c35f8a65c25fad45158b7ae..5f2edaae170397b961813f99ea53eddac0d4af19 100644 (file)
--- a/cxgb3_release_notes.txt
+++ b/cxgb3_release_notes.txt
@@ -275,3 +275,10 @@ data to 64:
 
        server: ib_rdma_lat -c -I 64
        client: ib_rdma_lat -c -I 64 server_ip_addr
+
+5) If you're running NFSRDMA over Chelsio's T3 RNIC and your cients are
+using a 64KB page size (like PPC64 and IA64 systems) and your server is
+using a 4KB page size (like i386 and X86_64), then you need to mount the
+server using rsize=32768,wsize=32768 to avoid overrunning the Chelsio
+RNIC fast register limits.  This is a known firmware limitation in the
+Chelsio RNIC.

diff --git a/nfs-rdma.release-notes.txt b/nfs-rdma.release-notes.txt
index f055f7aa876d99fc3c63b4a6bd3d04ddd2017e71..fb25efbe24c2826e40f485a0c658dbfd65883934 100644 (file)
--- a/nfs-rdma.release-notes.txt
+++ b/nfs-rdma.release-notes.txt
@@ -195,3 +195,12 @@ NFS/RDMA Setup
     the "proto" field for the given mount.
 
   Congratulations! You're using NFS/RDMA!
+
+Known Issues
+~~~~~~~~~~~~~~~~~~~~~~~~
+
+If you're running NFSRDMA over Chelsio's T3 RNIC and your cients are using
+a 64KB page size (like PPC64 and IA64 systems) and your server is using a
+4KB page size (like i386 and X86_64), then you need to mount the server
+using rsize=32768,wsize=32768 to avoid overrunning the Chelsio RNIC fast
+register limits.  This is a known firmware limitation in the Chelsio RNIC.