linux/net/sunrpc
Chuck Lever 4a85a6a332 SUNRPC: Handle TCP socket sends with kernel_sendpage() again
Daire Byrne reports a ~50% aggregrate throughput regression on his
Linux NFS server after commit da1661b93b ("SUNRPC: Teach server to
use xprt_sock_sendmsg for socket sends"), which replaced
kernel_send_page() calls in NFSD's socket send path with calls to
sock_sendmsg() using iov_iter.

Investigation showed that tcp_sendmsg() was not using zero-copy to
send the xdr_buf's bvec pages, but instead was relying on memcpy.
This means copying every byte of a large NFS READ payload.

It looks like TLS sockets do indeed support a ->sendpage method,
so it's really not necessary to use xprt_sock_sendmsg() to support
TLS fully on the server. A mechanical reversion of da1661b93b is
not possible at this point, but we can re-implement the server's
TCP socket sendmsg path using kernel_sendpage().

Reported-by: Daire Byrne <daire@dneg.com>
BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=209439
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2020-12-18 12:28:41 -05:00
..
auth_gss SUNRPC: Remove XDRBUF_SPARSE_PAGES flag in gss_proxy upcall 2020-12-09 09:38:34 -05:00
xprtrdma svcrdma: support multiple Read chunks per RPC 2020-11-30 13:00:23 -05:00
addr.c net: sunrpc: Fix off-by-one issues in 'rpc_ntop6' 2020-05-27 10:08:26 -04:00
auth_null.c SUNRPC: Add rpc_auth::au_ralign field 2019-02-14 11:48:36 -05:00
auth_unix.c SUNRPC: Use the client user namespace when encoding creds 2019-04-26 16:24:32 -04:00
auth.c sunrpc: add missing newline when printing parameter 'auth_hashtable_size' by sysfs 2020-06-11 13:33:48 -04:00
backchannel_rqst.c The one new feature this time, from Anna Schumaker, is READ_PLUS, which 2020-10-22 09:44:27 -07:00
cache.c sunrpc: clean-up cache downcall 2020-12-09 09:38:34 -05:00
clnt.c SUNRPC: Clean up call_bind_status() observability 2020-09-21 10:21:09 -04:00
debugfs.c NFS client updates for Linux 5.3 2019-07-18 14:32:33 -07:00
Kconfig SUNRPC: remove RC4-HMAC-MD5 support from KerberosV 2020-09-11 14:39:15 +10:00
Makefile SUNRPC: remove generic cred code. 2018-12-19 13:52:46 -05:00
netns.h
rpc_pipe.c net: datagram: fix some kernel-doc markups 2020-11-17 14:15:03 -08:00
rpcb_clnt.c SUNRPC: Replace rpcbind dprintk call sites with tracepoints 2020-09-21 10:21:09 -04:00
sched.c SUNRPC: Remove remaining dprintks from sched.c 2020-09-21 10:21:09 -04:00
socklib.c skb_copy_and_csum_bits(): don't bother with the last argument 2020-08-20 15:45:13 -04:00
socklib.h SUNRPC: Refactor xs_sendpages() 2020-03-16 12:04:33 -04:00
stats.c proc: convert everything to "struct proc_ops" 2020-02-04 03:05:26 +00:00
sunrpc_syms.c sunrpc: check that domain table is empty at module unload. 2020-05-28 18:15:00 -04:00
sunrpc.h Replace HTTP links with HTTPS ones: NFS, SUNRPC, and LOCKD clients 2020-09-21 10:21:10 -04:00
svc_xprt.c SUNRPC: Move the svc_xdr_recvfrom() tracepoint 2020-11-30 13:00:24 -05:00
svc.c SUNRPC: Prepare for xdr_stream-style decoding on the server-side 2020-11-30 14:46:35 -05:00
svcauth_unix.c sunrpc: Remove unused function ip_map_update 2020-05-06 16:00:11 -04:00
svcauth.c sunrpc: check that domain table is empty at module unload. 2020-05-28 18:15:00 -04:00
svcsock.c SUNRPC: Handle TCP socket sends with kernel_sendpage() again 2020-12-18 12:28:41 -05:00
sysctl.c net/sunrpc: fix useless comparison in proc_do_xprt() 2020-11-08 16:28:25 -05:00
timer.c treewide: Add SPDX license identifier for missed files 2019-05-21 10:50:45 +02:00
xdr.c NFSD: Replace the internals of the READ_BUF() macro 2020-11-30 14:46:36 -05:00
xprt.c SUNRPC: Mitigate cond_resched() in xprt_transmit() 2020-09-21 10:21:09 -04:00
xprtmultipath.c SUNRPC: Optimise transport balancing code 2019-07-18 14:43:52 -04:00
xprtsock.c SUNRPC: Replace dprintk() call site in xs_nospace() 2020-09-21 10:21:08 -04:00