- Don't need to count anonpages+filepages any more; clean+unknown+dirty for
each kind of page can be summed to get the totals.
- Track the number of free pages with a counter so that it's one less thing
for the allocator to do, which opens up further options there.
- Remove cpu_count_sync_one(). It has no users and doesn't save a whole lot.
For the cheap option, give cpu_count_sync() a boolean parameter indicating
that a cached value is okay, and rate limit the updates for cached values
to hz.
cached value will do, or if the very latest total must be fetched. It can
be called thousands of times a second and fetching the totals impacts not
only the calling LWP but other CPUs doing unrelated activity in the VM
system.
Once BIOCLOCK is executed, the device becomes locked which prevents the
execution of ioctl(2) commands which can change the underlying parameters
of the bpf(4) device. An example might be the setting of bpf(4) filter
programs or attaching to different network interfaces.
BIOCSETWF can be used to set write filters for outgoing packets.
Currently if a bpf(4) consumer is compromised, the bpf(4) descriptor can
essentially be used as a raw socket, regardless of consumer's UID.
Write filters give users the ability to constrain which packets can be sent
through the bpf(4) descriptor.
Taken from OpenBSD.
pthread_t, so there's less chance of bad things happening if someone calls
(for example) pthread_cond_broadcast() from a signal handler.
- Remove all the deferred waiter handling except for the one case that really
matters which is transferring waiters from condvar -> mutex on wakeup, and
do that by splicing the condvar's waiters onto the mutex.
- Remove the mutex waiters bit as it's another complication that's not
strictly needed.
llvm-symbolizer is an alternative for GNU addr2line(1), heavily used by the
LLVM sanitizers.
Do not install it as tools as it is not necessary as of today in that
stage.
