Kent!
On Sun, Jun 02 2024 at 20:33, Kent Overstreet wrote:
> +/*
> + * ringbuffer_ptrs - head and tail pointers for a ringbuffer, mappped to
> + * userspace:
> + */
> +struct ringbuffer_ptrs {
The naming is confusing. ringbuffer_ctrl or something like that would be
more clear because it's more than just the pointers, which are in fact
positions. You have size, mask ... too, no?
> + /*
> + * We use u32s because this type is shared between the kernel and
> + * userspace - ulong/size_t won't work here, we might be 32bit userland
> + * and 64 bit kernel, and u64 would be preferable (reduced probability
> + * of ABA) but not all architectures can atomically read/write to a u64;
> + * we need to avoid torn reads/writes.
union rbmagic {
u64 __val64;
struct {
// TOOTIRED: Add big/little endian voodoo
u32 __val32;
u32 __unused;
};
};
Plus a bunch of accessors which depend on BITS_PER_LONG, no?
Thanks,
tglx
