2013-09-05 02:59:01

by Myklebust, Trond

[permalink] [raw]
Subject: [PATCH 1/3] SUNRPC: Ensure that task->tk_pid is unique...

Replace the task->tk_pid with a guaranteed unique parameter.

Signed-off-by: Trond Myklebust <[email protected]>
---
include/linux/sunrpc/sched.h | 3 ++-
net/sunrpc/sched.c | 57 +++++++++++++++++++++++++++++++++++++-------
2 files changed, 51 insertions(+), 9 deletions(-)

diff --git a/include/linux/sunrpc/sched.h b/include/linux/sunrpc/sched.h
index 8ebb7c0..6e8657c 100644
--- a/include/linux/sunrpc/sched.h
+++ b/include/linux/sunrpc/sched.h
@@ -80,7 +80,7 @@ struct rpc_task {
unsigned short tk_timeouts; /* maj timeouts */

#if defined(RPC_DEBUG) || defined(RPC_TRACEPOINTS)
- unsigned short tk_pid; /* debugging aid */
+ unsigned int tk_pid; /* debugging aid */
#endif
unsigned char tk_priority : 2,/* Task priority */
tk_garb_retry : 2,
@@ -133,6 +133,7 @@ struct rpc_task_setup {
#define RPC_TASK_RUNNING 0
#define RPC_TASK_QUEUED 1
#define RPC_TASK_ACTIVE 2
+#define RPC_TASK_PID 3

#define RPC_IS_RUNNING(t) test_bit(RPC_TASK_RUNNING, &(t)->tk_runstate)
#define rpc_set_running(t) set_bit(RPC_TASK_RUNNING, &(t)->tk_runstate)
diff --git a/net/sunrpc/sched.c b/net/sunrpc/sched.c
index ff3cc4b..fd15110 100644
--- a/net/sunrpc/sched.c
+++ b/net/sunrpc/sched.c
@@ -259,24 +259,55 @@ static int rpc_wait_bit_killable(void *word)
}

#if defined(RPC_DEBUG) || defined(RPC_TRACEPOINTS)
-static void rpc_task_set_debuginfo(struct rpc_task *task)
+static DEFINE_IDA(rpc_pids);
+
+static int rpc_task_alloc_pid(struct rpc_task *task)
{
- static atomic_t rpc_pid;
+ int pid;
+
+ pid = ida_simple_get(&rpc_pids, 0, 0, GFP_NOFS);
+ if (pid < 0)
+ return pid;
+ task->tk_pid = pid;
+ set_bit(RPC_TASK_PID, &task->tk_runstate);
+ return 0;
+}

- task->tk_pid = atomic_inc_return(&rpc_pid);
+static bool rpc_task_need_free_pid(struct rpc_task *task)
+{
+ return test_and_clear_bit(RPC_TASK_PID, &task->tk_runstate) != 0;
+}
+
+static void rpc_task_free_pid(int pid)
+{
+ ida_simple_remove(&rpc_pids, pid);
}
#else
-static inline void rpc_task_set_debuginfo(struct rpc_task *task)
+static int rpc_task_alloc_pid(struct rpc_task *task)
+{
+ return 0;
+}
+
+static bool rpc_task_need_free_pid(struct rpc_task *task)
+{
+ return false;
+}
+
+static void rpc_task_free_pid(int pid)
{
}
#endif

-static void rpc_set_active(struct rpc_task *task)
+static int rpc_set_active(struct rpc_task *task)
{
- trace_rpc_task_begin(task->tk_client, task, NULL);
+ int ret;

- rpc_task_set_debuginfo(task);
+ ret = rpc_task_alloc_pid(task);
+ if (ret < 0)
+ return ret;
+ trace_rpc_task_begin(task->tk_client, task, NULL);
set_bit(RPC_TASK_ACTIVE, &task->tk_runstate);
+ return 0;
}

/*
@@ -811,8 +842,14 @@ static void __rpc_execute(struct rpc_task *task)
void rpc_execute(struct rpc_task *task)
{
bool is_async = RPC_IS_ASYNC(task);
+ int ret;

- rpc_set_active(task);
+ ret = rpc_set_active(task);
+ if (ret < 0) {
+ task->tk_status = ret;
+ rpc_release_task(task);
+ return;
+ }
rpc_make_runnable(task);
if (!is_async)
__rpc_execute(task);
@@ -970,6 +1007,8 @@ struct rpc_task *rpc_new_task(const struct rpc_task_setup *setup_data)
static void rpc_free_task(struct rpc_task *task)
{
unsigned short tk_flags = task->tk_flags;
+ bool free_pid = rpc_task_need_free_pid(task);
+ int pid = task->tk_pid;

rpc_release_calldata(task->tk_ops, task->tk_calldata);

@@ -977,6 +1016,8 @@ static void rpc_free_task(struct rpc_task *task)
dprintk("RPC: %5u freeing task\n", task->tk_pid);
mempool_free(task, rpc_task_mempool);
}
+ if (free_pid)
+ rpc_task_free_pid(pid);
}

static void rpc_async_release(struct work_struct *work)
--
1.8.3.1



2013-09-05 02:59:01

by Myklebust, Trond

[permalink] [raw]
Subject: [PATCH 3/3] SUNRPC: Replace pointer values with task->tk_pid and rpc_clnt->cl_clid

Instead of the pointer values, use the task and client identifier values
for tracing purposes.

Signed-off-by: Trond Myklebust <[email protected]>
---
include/trace/events/sunrpc.h | 50 ++++++++++++++++++++++---------------------
1 file changed, 26 insertions(+), 24 deletions(-)

diff --git a/include/trace/events/sunrpc.h b/include/trace/events/sunrpc.h
index b74a8ac..d51d16c 100644
--- a/include/trace/events/sunrpc.h
+++ b/include/trace/events/sunrpc.h
@@ -17,18 +17,20 @@ DECLARE_EVENT_CLASS(rpc_task_status,
TP_ARGS(task),

TP_STRUCT__entry(
- __field(const struct rpc_task *, task)
- __field(const struct rpc_clnt *, clnt)
+ __field(unsigned int, task_id)
+ __field(unsigned int, client_id)
__field(int, status)
),

TP_fast_assign(
- __entry->task = task;
- __entry->clnt = task->tk_client;
+ __entry->task_id = task->tk_pid;
+ __entry->client_id = task->tk_client->cl_clid;
__entry->status = task->tk_status;
),

- TP_printk("task:%p@%p, status %d",__entry->task, __entry->clnt, __entry->status)
+ TP_printk("task:%u@%u, status %d",
+ __entry->task_id, __entry->client_id,
+ __entry->status)
);

DEFINE_EVENT(rpc_task_status, rpc_call_status,
@@ -49,18 +51,20 @@ TRACE_EVENT(rpc_connect_status,
TP_ARGS(task, status),

TP_STRUCT__entry(
- __field(const struct rpc_task *, task)
- __field(const struct rpc_clnt *, clnt)
+ __field(unsigned int, task_id)
+ __field(unsigned int, client_id)
__field(int, status)
),

TP_fast_assign(
- __entry->task = task;
- __entry->clnt = task->tk_client;
+ __entry->task_id = task->tk_pid;
+ __entry->client_id = task->tk_client->cl_clid;
__entry->status = status;
),

- TP_printk("task:%p@%p, status %d",__entry->task, __entry->clnt, __entry->status)
+ TP_printk("task:%u@%u, status %d",
+ __entry->task_id, __entry->client_id,
+ __entry->status)
);

DECLARE_EVENT_CLASS(rpc_task_running,
@@ -70,8 +74,8 @@ DECLARE_EVENT_CLASS(rpc_task_running,
TP_ARGS(clnt, task, action),

TP_STRUCT__entry(
- __field(const struct rpc_clnt *, clnt)
- __field(const struct rpc_task *, task)
+ __field(unsigned int, task_id)
+ __field(unsigned int, client_id)
__field(const void *, action)
__field(unsigned long, runstate)
__field(int, status)
@@ -79,17 +83,16 @@ DECLARE_EVENT_CLASS(rpc_task_running,
),

TP_fast_assign(
- __entry->clnt = clnt;
- __entry->task = task;
+ __entry->client_id = clnt->cl_clid;
+ __entry->task_id = task->tk_pid;
__entry->action = action;
__entry->runstate = task->tk_runstate;
__entry->status = task->tk_status;
__entry->flags = task->tk_flags;
),

- TP_printk("task:%p@%p flags=%4.4x state=%4.4lx status=%d action=%pf",
- __entry->task,
- __entry->clnt,
+ TP_printk("task:%u@%u flags=%4.4x state=%4.4lx status=%d action=%pf",
+ __entry->task_id, __entry->client_id,
__entry->flags,
__entry->runstate,
__entry->status,
@@ -128,8 +131,8 @@ DECLARE_EVENT_CLASS(rpc_task_queued,
TP_ARGS(clnt, task, q),

TP_STRUCT__entry(
- __field(const struct rpc_clnt *, clnt)
- __field(const struct rpc_task *, task)
+ __field(unsigned int, task_id)
+ __field(unsigned int, client_id)
__field(unsigned long, timeout)
__field(unsigned long, runstate)
__field(int, status)
@@ -138,8 +141,8 @@ DECLARE_EVENT_CLASS(rpc_task_queued,
),

TP_fast_assign(
- __entry->clnt = clnt;
- __entry->task = task;
+ __entry->client_id = clnt->cl_clid;
+ __entry->task_id = task->tk_pid;
__entry->timeout = task->tk_timeout;
__entry->runstate = task->tk_runstate;
__entry->status = task->tk_status;
@@ -147,9 +150,8 @@ DECLARE_EVENT_CLASS(rpc_task_queued,
__assign_str(q_name, rpc_qname(q));
),

- TP_printk("task:%p@%p flags=%4.4x state=%4.4lx status=%d timeout=%lu queue=%s",
- __entry->task,
- __entry->clnt,
+ TP_printk("task:%u@%u flags=%4.4x state=%4.4lx status=%d timeout=%lu queue=%s",
+ __entry->task_id, __entry->client_id,
__entry->flags,
__entry->runstate,
__entry->status,
--
1.8.3.1


2013-09-05 02:59:01

by Myklebust, Trond

[permalink] [raw]
Subject: [PATCH 2/3] SUNRPC: Add an identifier for struct rpc_clnt

Add an identifier in order to aid debugging.

Signed-off-by: Trond Myklebust <[email protected]>
---
include/linux/sunrpc/clnt.h | 1 +
net/sunrpc/clnt.c | 25 +++++++++++++++++++++++++
2 files changed, 26 insertions(+)

diff --git a/include/linux/sunrpc/clnt.h b/include/linux/sunrpc/clnt.h
index 76c0bf6..6740801 100644
--- a/include/linux/sunrpc/clnt.h
+++ b/include/linux/sunrpc/clnt.h
@@ -33,6 +33,7 @@ struct rpc_inode;
*/
struct rpc_clnt {
atomic_t cl_count; /* Number of references */
+ unsigned int cl_clid; /* client id */
struct list_head cl_clients; /* Global list of clients */
struct list_head cl_tasks; /* List of tasks */
spinlock_t cl_lock; /* spinlock */
diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
index 0cd5b6d5..0a79069 100644
--- a/net/sunrpc/clnt.c
+++ b/net/sunrpc/clnt.c
@@ -313,6 +313,24 @@ out:
return err;
}

+static DEFINE_IDA(rpc_clids);
+
+static int rpc_alloc_clid(struct rpc_clnt *clnt)
+{
+ int clid;
+
+ clid = ida_simple_get(&rpc_clids, 0, 0, GFP_KERNEL);
+ if (clid < 0)
+ return clid;
+ clnt->cl_clid = clid;
+ return 0;
+}
+
+static void rpc_free_clid(struct rpc_clnt *clnt)
+{
+ ida_simple_remove(&rpc_clids, clnt->cl_clid);
+}
+
static struct rpc_clnt * rpc_new_client(const struct rpc_create_args *args,
struct rpc_xprt *xprt,
struct rpc_clnt *parent)
@@ -343,6 +361,10 @@ static struct rpc_clnt * rpc_new_client(const struct rpc_create_args *args,
goto out_err;
clnt->cl_parent = parent ? : clnt;

+ err = rpc_alloc_clid(clnt);
+ if (err)
+ goto out_no_clid;
+
rcu_assign_pointer(clnt->cl_xprt, xprt);
clnt->cl_procinfo = version->procs;
clnt->cl_maxproc = version->nrprocs;
@@ -386,6 +408,8 @@ static struct rpc_clnt * rpc_new_client(const struct rpc_create_args *args,
out_no_path:
rpc_free_iostats(clnt->cl_metrics);
out_no_stats:
+ rpc_free_clid(clnt);
+out_no_clid:
kfree(clnt);
out_err:
rpciod_down();
@@ -646,6 +670,7 @@ rpc_free_client(struct rpc_clnt *clnt)
clnt->cl_metrics = NULL;
xprt_put(rcu_dereference_raw(clnt->cl_xprt));
rpciod_down();
+ rpc_free_clid(clnt);
kfree(clnt);
}

--
1.8.3.1