提交 · e9d476393504ff0f9ab38d88d7857ec6a2c81ff6 · openanolis / cloud-kernel

14 7月, 2016 2 次提交

SUNRPC: Add tracepoints for dropped and deferred requests · 104f6351

由 Trond Myklebust 提交于 6月 24, 2016

Dropping and/or deferring requests has an impact on performance. Let's
make sure we can trace those events.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

104f6351

SUNRPC: Add a tracepoint for server socket out-of-space conditions · 82ea2d76

由 Trond Myklebust 提交于 6月 24, 2016

Add a tracepoint to track when the processing of incoming RPC data gets
deferred due to out-of-space issues on the outgoing transport.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

82ea2d76

02 7月, 2016 1 次提交

SUNRPC: Don't allocate a full sockaddr_storage for tracing · db1bb44c

由 Trond Myklebust 提交于 6月 24, 2016

We're always tracing IPv4 or IPv6 addresses, so we can save a lot
of space on the ringbuffer by allocating the correct sockaddr size.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>
Cc: stable@vger.kernel.org
Fixes: 83a712e0 "sunrpc: add some tracepoints around ..."
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

db1bb44c

01 9月, 2015 1 次提交

net: sunrpc: fix tracepoint Warning: unknown op '->' · 051ac384

由 Pratyush Anand 提交于 8月 27, 2015

`perf stat  -e sunrpc:svc_xprt_do_enqueue true` results in

Warning: unknown op '->'
Warning: [sunrpc:svc_xprt_do_enqueue] unknown op '->'

Similar warning for svc_handle_xprt as well.

Actually TP_printk() should never dereference an address saved in the ring
buffer that points somewhere in the kernel. There's no guarantee that that
object still exists (with the exception of static strings).

Therefore change all the arguments for TP_printk(), so that it references
values existing in the ring buffer only.

While doing that, also fix another possible bug when argument xprt could be
NULL and TP_fast_assign() tries to access it's elements.
Signed-off-by: NPratyush Anand <panand@redhat.com>
Reviewed-by: NJeff Layton <jeff.layton@primarydata.com>
Acked-by: NSteven Rostedt <rostedt@goodmis.org>
Cc: stable@vger.kernel.org
Fixes: 83a712e0 "sunrpc: add some tracepoints around ..."
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

051ac384

08 4月, 2015 1 次提交

SUNRPC: Export enums in tracepoints to user space · 6ba16eef

由 Steven Rostedt (Red Hat) 提交于 3月 27, 2015

The enums used in the tracepoints for __print_symbolic() have their
names shown in the tracepoint format files. User space tools do not know
how to convert those names into their values to be able to convert the
binary data.

Use TRACE_DEFINE_ENUM() to export the enum names to their values for
userspace to do the parsing correctly.

Link: http://lkml.kernel.org/r/20150403013802.220157513@goodmis.orgAcked-by: NTrond Myklebust <trond.myklebust@primarydata.com>
Reviewed-by: NMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Tested-by: NMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

6ba16eef

10 12月, 2014 8 次提交

sunrpc: add some tracepoints around enqueue and dequeue of svc_xprt · 83a712e0

由 Jeff Layton 提交于 11月 21, 2014

These were useful when I was tracking down a race condition between
svc_xprt_do_enqueue and svc_get_next_xprt.
Signed-off-by: NJeff Layton <jlayton@primarydata.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

83a712e0

sunrpc: convert to lockless lookup of queued server threads · b1691bc0

由 Jeff Layton 提交于 11月 21, 2014

Testing has shown that the pool->sp_lock can be a bottleneck on a busy
server. Every time data is received on a socket, the server must take
that lock in order to dequeue a thread from the sp_threads list.

Address this problem by eliminating the sp_threads list (which contains
threads that are currently idle) and replacing it with a RQ_BUSY flag in
svc_rqst. This allows us to walk the sp_all_threads list under the
rcu_read_lock and find a suitable thread for the xprt by doing a
test_and_set_bit.

Note that we do still have a potential atomicity problem however with
this approach. We don't want svc_xprt_do_enqueue to set the
rqst->rq_xprt pointer unless a test_and_set_bit of RQ_BUSY returned
zero (which indicates that the thread was idle). But, by the time we
check that, the bit could be flipped by a waking thread.

To address this, we acquire a new per-rqst spinlock (rq_lock) and take
that before doing the test_and_set_bit. If that returns false, then we
can set rq_xprt and drop the spinlock. Then, when the thread wakes up,
it must set the bit under the same spinlock and can trust that if it was
already set then the rq_xprt is also properly set.

With this scheme, the case where we have an idle thread no longer needs
to take the highly contended pool->sp_lock at all, and that removes the
bottleneck.

That still leaves one issue: What of the case where we walk the whole
sp_all_threads list and don't find an idle thread? Because the search is
lockess, it's possible for the queueing to race with a thread that is
going to sleep. To address that, we queue the xprt and then search again.

If we find an idle thread at that point, we can't attach the xprt to it
directly since that might race with a different thread waking up and
finding it. All we can do is wake the idle thread back up and let it
attempt to find the now-queued xprt.
Signed-off-by: NJeff Layton <jlayton@primarydata.com>
Tested-by: NChris Worley <chris.worley@primarydata.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

b1691bc0

sunrpc: add a rcu_head to svc_rqst and use kfree_rcu to free it · 81244386

由 Jeff Layton 提交于 11月 21, 2014

...also make the manipulation of sp_all_threads list use RCU-friendly
functions.
Signed-off-by: NJeff Layton <jlayton@primarydata.com>
Tested-by: NChris Worley <chris.worley@primarydata.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

81244386

sunrpc: move rq_splice_ok flag into rq_flags · 779fb0f3