pool(9): remove ticks

Change the pool(9) timeouts to use the system uptime instead of ticks.

- Change the timeouts from variables to macros so we can use
  SEC_TO_NSEC().  This means these timeouts are no longer patchable
  via ddb(4).  dlg@ does not think this will be a problem, as the
  timeout intervals have not changed in years.

- Use low-res time to keep things fast.  Add a local copy of
  getnsecuptime() to subr_pool.c to keep the diff small.  We will need
  to move getnsecuptime() into kern_tc.c and document it later if we
  ever have other users elsewhere in the kernel.

- Rename ph_tick -> ph_timestamp and pr_cache_tick -> pr_cache_timestamp.

Prompted by tedu@ some time ago, but the effort stalled (may have been
my fault).  Input from kettenis@ and dlg@.

Special thanks to mpi@ for help with struct shuffling.  This change
does not increase the size of struct pool_page_header or struct pool.

ok dlg@ mpi@

0 files changed, 0 insertions, 0 deletions