- Allocate only one struct pipe not two (no need to be bidirectional here).
- Then use f_flag (FREAD/FWRITE) to figure out what to do in the fileops.
- Never wake the other side or acquire long-term (I/O) lock unless needed.
- Whenever possible, defer wakeups until after locks have been released.
- Do some things locklessly in pipe_ioctl() and pipe_poll().
Some notable results:
- -30% latency on a 486DX2/66 doing 1 byte ping-pong within a single process.
- 2.5x less lock contention during "make cleandir" of src on a 48 CPU machine.
- 1.5x bandwith with 1kB messages on the same 48 CPU machine (8kB: same b/w).
Rename compiler-warning-disable variables from
GCC_NO_warning
to
CC_WNO_warning
where warning is the full warning name as used by the compiler.
GCC_NO_IMPLICIT_FALLTHRU is CC_WNO_IMPLICIT_FALLTHROUGH
Using the convention CC_compilerflag, where compilerflag
is based on the full compiler flag name.
GCC_NO_FORMAT_TRUNCATION -Wno-format-truncation (GCC 7/8)
GCC_NO_STRINGOP_TRUNCATION -Wno-stringop-truncation (GCC 8)
GCC_NO_STRINGOP_OVERFLOW -Wno-stringop-overflow (GCC 8)
GCC_NO_CAST_FUNCTION_TYPE -Wno-cast-function-type (GCC 8)
use these to turn off warnings for most GCC-8 complaints. many
of these are false positives, most of the real bugs are already
commited, or are yet to come.
we plan to introduce versions of (some?) of these that use the
"-Wno-error=" form, which still displays the warnings but does
not make it an error, and all of the above will be re-considered
as either being "fix me" (warning still displayed) or "warning
is wrong."
compatibility with BIOC[GS]SEESENT ioctl. The userland interface is the same
as FreeBSD.
This change also fixes a bug that the direction is misunderstand on some
environment by passing the direction to bpf_mtap*() instead of checking
m->m_pkthdr.rcvif.
and not exposed to userland, except do expose struct mount if __EXPOSE_MOUNT
is defined. define __EXPOSE_MOUNT in the kmem grovellers that want
the definition. needed for ZFS.
default, build a handful of tools as n64 so they work properly.
unfortunately, they're also static as dynamic n64 has a problem.
of these tools pstat is probably the lowest hanging fruit to convert
to sysctl. systat would be close were it not for the netstat screen,
which includes netstat itself.
the rest are difficult to perhaps foolish.
the upside is that netstat, pmap and fstat all work properly now.
- Push /dev/random `information-theoretic' accounting into cprng(9).
- Use percpu(9) for the per-CPU CPRNGs.
- Use atomics with correct memory barriers for lazy CPRNG creation.
- Remove /dev/random file kmem grovelling from fstat(1).
rndsink(9):
- Simplify API.
- Simplify locking scheme.
- Add a man page.
- Avoid races in destruction.
- Avoid races in requesting entropy now and scheduling entropy later.
Periodic distribution of entropy to sinks reduces the need for the
last one, but this way we don't need to rely on periodic distribution
(e.g., in a future tickless NetBSD).
rndsinks_lock should probably eventually merge with the rndpool lock,
but we'll put that off for now.
cprng(9):
- Make struct cprng_strong opaque.
- Move rndpseudo.c parts that futz with cprng guts to subr_cprng.c.
- Fix kevent locking. (Is kevent locking documented anywhere?)
- Stub out rump cprng further until we can rumpify rndsink instead.
- Strip code to grovel through struct cprng_strong in fstat.
available in a default installation (/usr/src isn't);
- put together two lines which belong to the same sentence;
- remove a spurious space character;
- remove unneeded consecutive argument for `.Nm' macro.
From Bug Hunting.
martin