Re: [PATCH v3 0/5] Add new system call for non-destructive peek and inspection to posix ipc mqueue

On Mon, Apr 13, 2026 at 5:40=E2=80=AFPM Mathura <[email protected]=
> wrote:
>
> Well, I will see that for reference
> Before that here is quick question from my side-
> Which better and clean approach
>
> 1) Current implementation follows one system call to one msg copy to
> user space as per priority and FIFO with a given index value from
> posix IPC RB Tree, this allows us  to go beyond Just from peek to
> early inspection in some other use case by passing valid index.
>
> 2) Just dump everything  and all data in one call to user space.

It probably will not work reliably. I think we can do something
inspired by recvmmsg:

mq_recvmmsg(mqdes, iovec, iovec_len, attrs, attrs_len, flags)

where attrs is an extandable structure:
struct mq_recvmmsg_attrs {
  uint64_t peek_offset; // MSG_PEEK
  /* new fields can be added in the future */
}

It is just an idea...

Thanks,
Andrei