• David Howells's avatar
    pipe: Allow pipes to have kernel-reserved slots · 6718b6f8
    David Howells authored
    Split pipe->ring_size into two numbers:
    
     (1) pipe->ring_size - indicates the hard size of the pipe ring.
    
     (2) pipe->max_usage - indicates the maximum number of pipe ring slots that
         userspace orchestrated events can fill.
    
    This allows for a pipe that is both writable by the general kernel
    notification facility and by userspace, allowing plenty of ring space for
    notifications to be added whilst preventing userspace from being able to
    pin too much unswappable kernel space.
    Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
    6718b6f8
iov_iter.c 41.9 KB