Merge tag 'trace-v6.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace...

Pull tracing fixes from Steven Rostedt:

 - Fix setting affinity of hwlat threads in containers

   Using sched_set_affinity() has unwanted side effects when being
   called within a container. Use set_cpus_allowed_ptr() instead

 - Fix per cpu thread management of the hwlat tracer:
    - Do not start per_cpu threads if one is already running for the CPU
    - When starting per_cpu threads, do not clear the kthread variable
      as it may already be set to running per cpu threads

 - Fix return value for test_gen_kprobe_cmd()

   On error the return value was overwritten by being set to the result
   of the call from kprobe_event_delete(), which would likely succeed,
   and thus have the function return success

 - Fix splice() reads from the trace file that was broken by commit
   36e2c7421f02 ("fs: don't allow splice read/write without explicit
   ops")

 - Remove obsolete and confusing comment in ring_buffer.c

   The original design of the ring buffer used struct page flags for
   tricks to optimize, which was shortly removed due to them being
   tricks. But a comment for those tricks remained

 - Set local functions and variables to static

* tag 'trace-v6.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  tracing/hwlat: Replace sched_setaffinity with set_cpus_allowed_ptr
  ring-buffer: remove obsolete comment for free_buffer_page()
  tracing: Make splice_read available again
  ftrace: Set direct_ops storage-class-specifier to static
  trace/hwlat: Do not start per-cpu thread if it is already running
  trace/hwlat: Do not wipe the contents of per-cpu thread data
  tracing/osnoise: set several trace_osnoise.c variables storage-class-specifier to static
  tracing: Fix wrong return in kprobe_event_gen_test.c

diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 9b2803c7a18f8e54fe99b02bd22794d0e52f58d8..0feea145bb2995e17ef79cad1596867be5f8caca 100644 (file)
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -2592,7 +2592,7 @@ static void call_direct_funcs(unsigned long ip, unsigned long pip,
        arch_ftrace_set_direct_caller(fregs, addr);
 }
 
-struct ftrace_ops direct_ops = {
+static struct ftrace_ops direct_ops = {
        .func           = call_direct_funcs,
        .flags          = FTRACE_OPS_FL_DIRECT | FTRACE_OPS_FL_SAVE_REGS
                          | FTRACE_OPS_FL_PERMANENT,

diff --git a/kernel/trace/kprobe_event_gen_test.c b/kernel/trace/kprobe_event_gen_test.c
index 4850fdfe27f1cb040118eed41c8a3036c4926d2c..5a4b722b50451bfdee42769a6d3be39c055690d1 100644 (file)
--- a/kernel/trace/kprobe_event_gen_test.c
+++ b/kernel/trace/kprobe_event_gen_test.c
@@ -146,7 +146,7 @@ static int __init test_gen_kprobe_cmd(void)
        if (trace_event_file_is_valid(gen_kprobe_test))
                gen_kprobe_test = NULL;
        /* We got an error after creating the event, delete it */
-       ret = kprobe_event_delete("gen_kprobe_test");
+       kprobe_event_delete("gen_kprobe_test");
        goto out;
 }
 
@@ -211,7 +211,7 @@ static int __init test_gen_kretprobe_cmd(void)
        if (trace_event_file_is_valid(gen_kretprobe_test))
                gen_kretprobe_test = NULL;
        /* We got an error after creating the event, delete it */
-       ret = kprobe_event_delete("gen_kretprobe_test");
+       kprobe_event_delete("gen_kretprobe_test");
        goto out;
 }
 

diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index af50d931b020227991e2e63f4e961c9d0618323f..c6f47b6cfd5f1b9420e2e0040a1734246fa875ef 100644 (file)
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -354,10 +354,6 @@ static void rb_init_page(struct buffer_data_page *bpage)
        local_set(&bpage->commit, 0);
 }
 
-/*
- * Also stolen from mm/slob.c. Thanks to Mathieu Desnoyers for pointing
- * this issue out.
- */
 static void free_buffer_page(struct buffer_page *bpage)
 {
        free_page((unsigned long)bpage->page);

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 45551c7b4c36588fac4378f04fe4a4d7ef8e36a9..937e9676dfd42fbff3e4efa02aab169325f10d84 100644 (file)
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -5167,6 +5167,8 @@ loff_t tracing_lseek(struct file *file, loff_t offset, int whence)
 static const struct file_operations tracing_fops = {
        .open           = tracing_open,
        .read           = seq_read,
+       .read_iter      = seq_read_iter,
+       .splice_read    = generic_file_splice_read,
        .write          = tracing_write_stub,
        .llseek         = tracing_lseek,
        .release        = tracing_release,

diff --git a/kernel/trace/trace_hwlat.c b/kernel/trace/trace_hwlat.c
index d440ddd5fd8b29adf605075004fc5edd9a7ee17c..2f37a6e68aa9f851f19b968eeafdb1034d3efae2 100644 (file)
--- a/kernel/trace/trace_hwlat.c
+++ b/kernel/trace/trace_hwlat.c
@@ -339,7 +339,7 @@ static void move_to_next_cpu(void)
        cpumask_clear(current_mask);
        cpumask_set_cpu(next_cpu, current_mask);
 
-       sched_setaffinity(0, current_mask);
+       set_cpus_allowed_ptr(current, current_mask);
        return;
 
  change_mode:
@@ -446,7 +446,7 @@ static int start_single_kthread(struct trace_array *tr)
 
        }
 
-       sched_setaffinity(kthread->pid, current_mask);
+       set_cpus_allowed_ptr(kthread, current_mask);
 
        kdata->kthread = kthread;
        wake_up_process(kthread);
@@ -492,6 +492,10 @@ static int start_cpu_kthread(unsigned int cpu)
 {
        struct task_struct *kthread;
 
+       /* Do not start a new hwlatd thread if it is already running */
+       if (per_cpu(hwlat_per_cpu_data, cpu).kthread)
+               return 0;
+
        kthread = kthread_run_on_cpu(kthread_fn, NULL, cpu, "hwlatd/%u");
        if (IS_ERR(kthread)) {
                pr_err(BANNER "could not start sampling thread\n");
@@ -584,9 +588,6 @@ static int start_per_cpu_kthreads(struct trace_array *tr)
         */
        cpumask_and(current_mask, cpu_online_mask, tr->tracing_cpumask);
 
-       for_each_online_cpu(cpu)
-               per_cpu(hwlat_per_cpu_data, cpu).kthread = NULL;
-
        for_each_cpu(cpu, current_mask) {
                retval = start_cpu_kthread(cpu);
                if (retval)

diff --git a/kernel/trace/trace_osnoise.c b/kernel/trace/trace_osnoise.c
index 04f0fdae19a1c0382d6e0ec4f415a36d86d610f7..9176bb7a9bb459399b7518e3a1caf24e01d7a16f 100644 (file)
--- a/kernel/trace/trace_osnoise.c
+++ b/kernel/trace/trace_osnoise.c
@@ -217,7 +217,7 @@ struct osnoise_variables {
 /*
  * Per-cpu runtime information.
  */
-DEFINE_PER_CPU(struct osnoise_variables, per_cpu_osnoise_var);
+static DEFINE_PER_CPU(struct osnoise_variables, per_cpu_osnoise_var);
 
 /*
  * this_cpu_osn_var - Return the per-cpu osnoise_variables on its relative CPU
@@ -240,7 +240,7 @@ struct timerlat_variables {
        u64                     count;
 };
 
-DEFINE_PER_CPU(struct timerlat_variables, per_cpu_timerlat_var);
+static DEFINE_PER_CPU(struct timerlat_variables, per_cpu_timerlat_var);
 
 /*
  * this_cpu_tmr_var - Return the per-cpu timerlat_variables on its relative CPU
@@ -332,7 +332,7 @@ struct timerlat_sample {
 /*
  * Protect the interface.
  */
-struct mutex interface_lock;
+static struct mutex interface_lock;
 
 /*
  * Tracer data.
@@ -2239,8 +2239,8 @@ static struct trace_min_max_param osnoise_print_stack = {
 /*
  * osnoise/timerlat_period: min 100 us, max 1 s
  */
-u64 timerlat_min_period = 100;
-u64 timerlat_max_period = 1000000;
+static u64 timerlat_min_period = 100;
+static u64 timerlat_max_period = 1000000;
 static struct trace_min_max_param timerlat_period = {
        .lock   = &interface_lock,
        .val    = &osnoise_data.timerlat_period,