diff options
| author | Wei Li <[email protected]> | 2024-09-24 17:45:11 +0800 |
|---|---|---|
| committer | Steven Rostedt (Google) <[email protected]> | 2024-10-03 16:43:22 -0400 |
| commit | 0bb0a5c12ecf36ad561542bbb95f96355e036a02 (patch) | |
| tree | 5c2bcfb85338faf0b03188fb921ca4387975d578 /kernel | |
| parent | ad686707ea16099a791bcdcd5372764c5059aecc (diff) | |
tracing/timerlat: Fix duplicated kthread creation due to CPU online/offline
osnoise_hotplug_workfn() is the asynchronous online callback for
"trace/osnoise:online". It may be congested when a CPU goes online and
offline repeatedly and is invoked for multiple times after a certain
online.
This will lead to kthread leak and timer corruption. Add a check
in start_kthread() to prevent this situation.
Cc: [email protected]
Cc: Masami Hiramatsu <[email protected]>
Cc: Mathieu Desnoyers <[email protected]>
Link: https://lore.kernel.org/[email protected]
Fixes: c8895e271f79 ("trace/osnoise: Support hotplug operations")
Signed-off-by: Wei Li <[email protected]>
Signed-off-by: Steven Rostedt (Google) <[email protected]>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/trace/trace_osnoise.c | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/kernel/trace/trace_osnoise.c b/kernel/trace/trace_osnoise.c index 1439064f65d6..d1a539913a5f 100644 --- a/kernel/trace/trace_osnoise.c +++ b/kernel/trace/trace_osnoise.c @@ -2007,6 +2007,10 @@ static int start_kthread(unsigned int cpu) void *main = osnoise_main; char comm[24]; + /* Do not start a new thread if it is already running */ + if (per_cpu(per_cpu_osnoise_var, cpu).kthread) + return 0; + if (timerlat_enabled()) { snprintf(comm, 24, "timerlat/%d", cpu); main = timerlat_main; @@ -2061,11 +2065,10 @@ static int start_per_cpu_kthreads(void) if (cpumask_test_and_clear_cpu(cpu, &kthread_cpumask)) { struct task_struct *kthread; - kthread = per_cpu(per_cpu_osnoise_var, cpu).kthread; + kthread = xchg_relaxed(&(per_cpu(per_cpu_osnoise_var, cpu).kthread), NULL); if (!WARN_ON(!kthread)) kthread_stop(kthread); } - per_cpu(per_cpu_osnoise_var, cpu).kthread = NULL; } for_each_cpu(cpu, current_mask) { |