and minor fixes:
. add ack/clean target to lib, 'unify' clean target
. add includes as library dependency
. mk: exclude warning options clang doesn't have in non-gcc
. set -e in lib/*.sh build files
. clang compile error circumvention (disable NOASSERTS for release builds)
. when switching from the base pkg_install to the pkgin pkg_install,
the version number changed, causing a compatability problem if the
old base system binary was inadvertently left behind.
. this change checks for that situation by specifically invoking
the pkgin instance of pkg_install and telling the user to install
it if it doesn't exist.
pkgsrc binary packages.
rationale:
. pkg_install (which is the pkg_* tools) is entangled with pkgsrc,
not with minix, so tracking it from pkgsrc (easier than with
base system) makes more sense
. simplifies upstreaming minix specific changes for pkg_* tools
. reduce pkgsrc-in-basesystem maintenance burden
. update release.sh's notion of where packages are
. update release.sh's notion of how many files are on root
as -xdev won't work anymore to separate /usr from /
- A staging directory is always used to avoid oversized images;
- As a consequence, the zero-filling is removed so no more "out of
space" errors should be printed to the console;
- The root and usr partition sizes are computed so less space should be
wasted (the root partition gets extra 1MB zones and 64 inodes for
run-time though and hardlinks/holes make the used space slightly less
than expected); USRMB (and the new ROOTMB) are now used to enforce
a minimum size rather than set the size;
- TMPDISK1-3 are renamed to more meaningful names (and TMPDISK2 is
dropped because a separate tmp directory is no longer needed);
- The ramdisks are truncated at the end to save memory (not sure
whether it is actually released though).
In this second phase, scheduling is moved from PM to its own
scheduler (see r6557 for phase one). In the next phase we hope to a)
include useful information in the "out of quantum" message and b)
create some simple scheduling policy that makes use of that
information.
When the system starts up, PM will iterate over its process table and
ask SCHED to take over scheduling unprivileged processes. This is
done by sending a SCHEDULING_START message to SCHED. This message
includes the processes endpoint, the parent's endpoint and its nice
level. The scheduler adds this process to its schedproc table, issues
a schedctl, and returns its own endpoint to PM - as the endpoint of
the effective scheduler. When a process terminates, a SCHEDULING_STOP
message is sent to the scheduler.
The reason for this effective endpoint is for future compatibility.
Some day, we may have a scheduler that, instead of scheduling the
process itself, forwards the SCHEDULING_START message on to another
scheduler.
PM has information on who schedules whom. As such, scheduling
messages from user-land are sent through PM. An example is when
processes change their priority, using nice(). In that case, a
getsetpriority message is sent to PM, which then sends a
SCHEDULING_SET_NICE to the process's effective scheduler.
When a process is forked through PM, it inherits its parent's
scheduler, but is spawned with an empty quantum. As before, a request
to fork a process flows through VM before returning to PM, which then
wakes up the child process. This flow has been modified slightly so
that PM notifies the scheduler of the new process, before waking up
the child process. If the scheduler fails to take over scheduling,
the child process is torn down and the fork fails with an erroneous
value.
Process priority is entirely decided upon using nice levels. PM
stores a copy of each process's nice level and when a child is
forked, its parent's nice level is sent in the SCHEDULING_START
message. How this level is mapped to a priority queue is up to the
scheduler. It should be noted that the nice level is used to
determine the max_priority and the parent could have been in a lower
priority when it was spawned. To prevent a CPU intensive process from
hawking the CPU by continuously forking children that get scheduled
in the max_priority, the scheduler should determine in which queue
the parent is currently scheduled, and schedule the child in that
same queue.
Other fixes: The USER_Q in kernel/proc.h was incorrectly defined as
NR_SCHED_QUEUES/2. That results in a "off by one" error when
converting priority->nice->priority for nice=0. This also had the
side effect that if someone were to set the MAX_USER_Q to something
else than 0, then USER_Q would be off.
boot is a normal binary with a.out again. use 'cdbootblock,' a CDBOOT
variant of bootblock, both from bootblock.s, as the first boot image
that then loads boot, exactly like the bootblock loads boot when booting
from harddisk. the sector numbers (2048 byte iso sectors) are patched in
by writeisofs, like installboot does for bootblock. bootblock unchanged.
