PAGE_SIZE pages (4k). An average small program uses ~6 4k pages (24k),
while the same program only uses ~20 512 byte pages (10k), so it will be
a small memory usage improvement. The large improvement will be the upcoming
ability to share page table pages between processes for shared libraries.
Remaining: should be able to give back ptp pages to the system.
PAGE_SIZE pages (4k). An average small program uses ~6 4k pages (24k),
while the same program only uses ~20 512 byte pages (10k), so it will be
a small memory usage improvement. The large improvement will be the upcoming
ability to share page table pages between processes for shared libraries.
Remaining: should be able to give back ptp pages to the system.
cd ${KERNSRCDIR}/${KERNARCHDIR}/compile && ${PRINTOBJDIR}
This is far simpler than the previous system, and more robust with
objdirs built via BSDOBJDIR.
The previous method of finding KERNOBJDIR when using BSDOBJDIR by
referencing _SRC_TOP_OBJ_ from another directory was extremely
fragile due to the depth first tree walk by <bsd.subdir.mk>, and
the caching of _SRC_TOP_OBJ_ (with MAKEOVERRIDES) which would be
empty on the *first* pass to create fresh objdirs.
This change requires adding sys/arch/*/compile/Makefile to create
the objdir in that directory, and descending into arch/*/compile
from arch/*/Makefile. Remove the now-unnecessary .keep_me files
whilst here.
Per lengthy discussion with Andrew Brown.
possible to use alternate system call tables. This is usefull for
displaying correctly the arguments in Mach binaries traces.
If NULL is given, then the regular systam call table for the process is used.
- All regs must be saved before any register is altered.
- movc{3,5} alters r0-r5, so clearing bss would clear the text instead.
This needs more thinking/testing to get it work correct; there are
different ways different CPUs call "boot".
noticed by and fix from Miod Vallat <miod@openbsd.org>.
Miod's OpenBSD log message:
> Don't uvm_useracc the user sigcontext in sys_sigreturn and then access
> the user addresses directly from the kernel. copyin is faster and can
> correctly deal properly with mappings that uvm_useracc thinks are
> correct but will fault anyway (to figure out how to generate such
> mappings is left as en excercise for the reader).
>
> Blatantly stolen from art@'s similar fix to sparc.
