Stream protocols such as TCP can often build up a backlog of data to be
read due to ordering. Combine this with the fact that some workloads such
as NFS read()-intensive workloads need to receive a lot of data per RPC
call, and it turns out that receiving the data from inside a softirq
context can cause starvation.
The following patch moves the TCP data receive into a workqueue context.
We still end up calling tcp_read_sock(), but we do so from a process
context, meaning that softirqs are enabled for most of the time.
With this patch, I see a doubling of read bandwidth when running a
multi-threaded iozone workload between a virtual client and server setup.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Commit 718ba5b873, moved the responsibility for unlocking the socket to
xs_tcp_setup_socket, meaning that the socket will be unlocked before we
know that it has finished trying to connect. The following patch is based on
an initial patch by Russell King to ensure that we delay clearing the
XPRT_CONNECTING flag until we either know that we failed to initiate
a connection attempt, or the connection attempt itself failed.
Fixes: 718ba5b873 ("SUNRPC: Add helpers to prevent socket create from racing")
Reported-by: Russell King <linux@arm.linux.org.uk>
Reported-by: Russell King <rmk+kernel@arm.linux.org.uk>
Tested-by: Russell King <rmk+kernel@arm.linux.org.uk>
Tested-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Add tracepoints inside the main loop on xs_tcp_data_recv that allow
us to keep an eye on what's happening during each phase of it.
Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
net/sunrpc/svcsock.c:412:22: warning: incorrect type in assignment
(different address spaces)
- svc_partial_recvfrom now takes a struct kvec, so the variable
save_iovbase needs to be an ordinary (void *)
Make a bunch of variables in net/sunrpc/xprtsock.c static
Fix a couple of "warning: symbol 'foo' was not declared. Should it be
static?" reports.
Fix a couple of conflicting function declarations.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
[sunrpc: change idle timeout value for the backchannel]
Signed-off-by: Alexandros Batsakis <batsakis@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Acked-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
To prepare for including non-sockets-based RPC transports, select
RPC transports by an identifier (to be used in following patches).
Signed-off-by: Tom Talpey <tmt@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
To prepare for including non-sockets-based RPC transports, move the
sockets-dependent definitions into their own file.
Signed-off-by: Tom Talpey <tmt@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
![](/avatar/511417582bfa18e9a88da2ada8339d64?size=56 "\\"Talpey, Thomas\"){kind=small}