use both types of list.
- Make page coloring and idle zero state per-CPU.
- Maintain per-CPU page freelists. When freeing, put pages onto the local
CPU's lists and the global lists. When allocating, prefer to take pages
from the local CPU. If none are available take from the global list as
done now. Proposed on tech-kern@.
- Don't use goto in critical paths, it can confuse the compiler.
- Sprinkle some branch hints.
- Make namecache stats per-CPU and collate once per second.
- Use vtryget().
to scale more gracefully when there are thousands of active threads.
Proposed on tech-kern@.
- Use LOCKDEBUG to catch some errors in the use of condition variables:
freeing an active CV
re-initializing an active CV
using multiple distinct mutexes during concurrent waits
not holding the interlocking mutex when calling cv_broadcast/cv_signal
waking waiters and destroying the CV before they run and exit it
- Tweak it so it can also catch common errors with condition variables.
The change to kern_condvar.c is not included in this commit and will
come later.
- Don't call kmem_alloc() if operating in interrupt context, just fail
the allocation and disable debugging for the object. Makes it safe
to do mutex_init/rw_init/cv_init in interrupt context, when running
a LOCKDEBUG kernel.
* NOTE: if you get a panic in this code block, it is likely that
* a lock has been destroyed or corrupted while still in use. Try
* compiling a kernel with LOCKDEBUG to pinpoint the problem.
mi_switch(), migration for LSONPROC is now performed via idle loop.
Handles/fixes on-CPU case in lwp_migrate(), misc.
Closes PR/38169, idea of migration via idle loop by Andrew Doran.
NetBSD's shutdown behavior of more than 6 years before rev 1.176.
Ok joerg@.
It is essential that we restore some hardware to initial conditions
before rebooting, in order to avoid interfering with the BIOS
bootstrap. For example, if NetBSD gives control back to the Soekris
comBIOS while the kernel text is write-protected, the BIOS bootstrap
hangs during the power-on self-test, "POST: 0123456789bcefghip".
In principle, bus masters can also interfere with BIOS boot.
