On Tue, Jan 23, 2024 at 10:51:49AM -0500, Steven Rostedt wrote: > On Tue, 23 Jan 2024 11:07:53 +0000 > Vincent Donnefort <vdonnef...@google.com> wrote: > > > index 000000000000..5468afc94be7 > > --- /dev/null > > +++ b/include/uapi/linux/trace_mmap.h > > @@ -0,0 +1,44 @@ > > +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ > > +#ifndef _TRACE_MMAP_H_ > > +#define _TRACE_MMAP_H_ > > + > > +#include <linux/types.h> > > + > > +/** > > + * struct trace_buffer_meta - Ring-buffer Meta-page description > > + * @meta_page_size: Size of this meta-page. > > + * @meta_struct_len: Size of this structure. > > + * @subbuf_size: Size of each subbuf, including the header. > > + * @nr_subbufs: Number of subbfs in the ring-buffer. > > + * @reader.lost_events: Number of events lost at the time of the reader > > swap. > > + * @reader.id: subbuf ID of the current reader. From 0 to > > @nr_subbufs - 1 > > + * @reader.read: Number of bytes read on the reader subbuf. > > + * @entries: Number of entries in the ring-buffer. > > + * @overrun: Number of entries lost in the ring-buffer. > > + * @read: Number of entries that have been read. > > > > + * @subbufs_touched: Number of subbufs that have been filled. > > + * @subbufs_lost: Number of subbufs lost to overrun. > > + * @subbufs_read: Number of subbufs that have been read. > > Do we actually need the above 3 fields? > > What's the use case for them? I don't want to expose internals in the API > unless they are needed.
subbufs_read is gone, I just forgot to remove it here :-\. The two other ones are used for tracing with the hypervisor. That's why I preemptively added them. I can remove them and add just append this struct later ... or just overload this struct with another one, only shared between the kernel and the hypervisor? > > -- Steve
