On Fri, 9 Feb 2024 10:21:58 +0000
Vincent Donnefort <vdonnef...@google.com> wrote:
> +static void rb_update_meta_page(struct ring_buffer_per_cpu *cpu_buffer)
> +{
> + struct trace_buffer_meta *meta = cpu_buffer->meta_page;
> +
> + WRITE_ONCE(meta->reader.read, cpu_buffer->reader_page->read);
> + WRITE_ONCE(meta->reader.id, cpu_buffer->reader_page->id);
> + WRITE_ONCE(meta->reader.lost_events, cpu_buffer->lost_events);
> +
> + WRITE_ONCE(meta->entries, local_read(&cpu_buffer->entries));
> + WRITE_ONCE(meta->overrun, local_read(&cpu_buffer->overrun));
> + WRITE_ONCE(meta->read, cpu_buffer->read);
> +
Small nit, but we should add a comment to the two flush_dache_folio() calls:
/* Some archs do not have data cache coherency between kernel and user
space */
> + flush_dcache_folio(virt_to_folio(cpu_buffer->meta_page));
> +}
> +
-- Steve
