Re: [PATCH v17 3/6] tracing: Add snapshot refcount

On Mon, 19 Feb 2024 13:17:54 -0500 Steven Rostedt wrote: > On Tue, 13 Feb 2024 11:49:42 + > Vincent Donnefort wrote: > > > @@ -9678,7 +9739,9 @@ trace_array_create_systems(const char *name, const > > char *systems) > > raw_spin_lock_init(&tr->start_lock); > > > > tr->max_lock = (

Re: [PATCH v17 3/6] tracing: Add snapshot refcount

On Tue, 13 Feb 2024 11:49:42 + Vincent Donnefort wrote: > @@ -9678,7 +9739,9 @@ trace_array_create_systems(const char *name, const char > *systems) > raw_spin_lock_init(&tr->start_lock); > > tr->max_lock = (arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED; > - > +#ifdef CONFIG_TRCER_M

[PATCH v17 3/6] tracing: Add snapshot refcount

When a ring-buffer is memory mapped by user-space, no trace or ring-buffer swap is possible. This means the snapshot feature is mutually exclusive with the memory mapping. Having a refcount on snapshot users will help to know if a mapping is possible or not. Instead of relying on the global trace_