net: poll/select low latency socket support
select/poll busy-poll support.
Split sysctl value into two separate ones, one for read and one for poll.
Add a new poll flag POLL_LL. When this flag is set, sock_poll will call
sk_poll_ll if possible. sock_poll sets this flag in its return value
to indicate to select/poll when a socket that can busy poll is found.
When poll/select have nothing to report, call the low-level
sock_poll again until we are out of time or we find something.
Once the system call finds something, it stops setting POLL_LL, so it can
return the result to the user ASAP.
Signed-off-by: Eliezer Tamir <firstname.lastname@example.org>
Signed-off-by: David S. Miller <email@example.com>
7 files changed