Messages in this thread | | | Date | Tue, 28 Mar 2023 22:44:11 -0400 | From | Steven Rostedt <> | Subject | Re: [PATCH v2 1/2] ring-buffer: Introducing ring-buffer mapping functions |
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On Wed, 22 Mar 2023 10:22:43 +0000 Vincent Donnefort <vdonnefort@google.com> wrote:
> +#include <linux/types.h> > + > +struct ring_buffer_meta_page_header { > +#if __BITS_PER_LONG == 64 > + __u64 entries; > + __u64 overrun; > +#else > + __u32 entries; > + __u32 overrun; > +#endif > + __u32 pages_touched; > + __u32 meta_page_size; > + __u32 reader_page; /* page ID for the reader page */ > + __u32 nr_data_pages; /* doesn't take into account the reader_page */ > + __u32 data_page_head; /* ring-buffer head as an offset from data_start */ > + __u32 data_start; /* offset within the meta page */ > +}; > +
I've been playing with this a bit, and I'm thinking, do we need the data_pages[] array on the meta page?
I noticed that I'm not even using it.
Currently, we need to do a ioctl every time we finish with the reader page, and that updates the reader_page in the meta data to point to the next page to read. When do we need to look at the data_start section?
-- Steve
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