These are of use to userland code which previously depended on the
hard-coded values of LABELSECTOR and LABELOFFSET to figure out the
location of the disklabel for a particular platform.
With the introduction of umbrella ports such as evbarm, evbmips, etc,
the location of the disklabel may vary between kernels for the same
MACHINE. This sysctl will allow userland programs to remain independent
of the particular flavour of MACHINE in such cases.
that can be used to block a process after fork(2) or exec(2) calls. The
new process is created in the SSTOP state and is never scheduled for running.
This feature is designed so that it is esay to attach the process using gdb
before it has done anything.
It works also with sproc, kthread_create, clone...
was successfully changed. previously, successfully viewing the
current value would flush the cache :-/
- similarly, don't change hostid and sb_max unless the value was
successfully changed
adjusted via sysctl. file systems that have hash tables which are
sized based on the value of this variable now resize those hash tables
using the new value. the max number of FFS softdeps is also recalculated.
convert various file systems to use the <sys/queue.h> macros for
their hash tables.
for FreeBSD project. Besides huge speed boost compared with socketpair-based
pipes, this implementation also uses pagable kernel memory instead of mbufs.
Significant differences to FreeBSD version:
* uses uvm_loan() facility for direct write
* async/SIGIO handling correct also for sync writer, async reader
* limits settable via sysctl, amountpipekva and nbigpipes available via sysctl
* pipes are unidirectional - this is enforced on file descriptor level
for now only, the code would be updated to take advantage of it
eventually
* uses lockmgr(9)-based locks instead of home brew variant
* scatter-gather write is handled correctly for direct write case, data
is transferred by PIPE_DIRECT_CHUNK bytes maximum, to avoid running out of kva
All FreeBSD/NetBSD specific code is within appropriate #ifdef, in preparation
to feed changes back to FreeBSD tree.
This pipe implementation is optional for now, add 'options NEW_PIPE'
to your kernel config to use it.
only signal handler array sharable between threads
move other random signal stuff from struct proc to struct sigctx
This addresses kern/10981 by Matthew Orgass.
to support arbitrary number of ptys without need of kernel recompile
(the extra device special files in /dev/ still need to be created, of course)
upper limit of supported ptys is controlled via new sysctl variable
kern.maxptys (KERN_MAXPTYS), which is raise-only and defaults to 512.
instead test for (p->p_flag & I_INMEM), and don't access the U-area
(via p->p_stats) if that bit is clear. Fixes the hangs people have
seen when the system is paging and the user runs top/ps/w.
vslock the user pages for the data being copied out to userspace,
so that we won't sleep while holding a lock in case we need to
fault the pages in.
- Sprinkle some const and ANSI'ify some things while here.
