Lowest priority interrupts are now delivered based on a rotating offset into
the list of potential recipients. There could be parasitic cases were a
processor gets picked on and ends up at that rotating offset all the time, but
it's much more likely that the group will stay consistent and the pain will be
distributed evenly.
This is a hack so that the IO APIC can figure out information about the local
APICs. The local APICs still have no way to find out about each other.
Ideally, when the local APICs update state that's relevant to somebody else,
they'd send an update to everyone. Without being able to do a broadcast, that
would still require knowing who else there is to notify. Other broadcasts are
implemented using assumptions that may not always be true.
The ID as exposed to software can be changed. Tracking those changes in M5
would be cumbersome, especially since there's no guarantee the IDs will remain
unique.
Previously there was one per bus, which caused some coherence problems
when more than one decided to respond. Now there is just one on
the main memory bus. The default bus responder on all other buses
is now the downstream cache's cpu_side port. Caches no longer need
to do address range filtering; instead, we just have a simple flag
to prevent snoops from propagating to the I/O bus.
env is used as a local variable all over the place and sometimes it is
easy to get confused as to whether the global env or local env is being
used. This will become especially important when I change the way we
support our variants.
1) -L is automatically added, so don't do it ourselves
2) prepend the paths for gzstream and libelf so they are certain to
come first. The problem is that python might add /usr/lib to the path
and the user might have a locally installed version of libelf installed.
Just one test (40.m5threads-test-atomic) is set up for now.
These tests require that the m5threads SPARC binaries are present
in /dist or in test-progs.
This patch adds limited multithreading support in syscall-emulation
mode, by using the clone system call. The clone system call works
for Alpha, SPARC and x86, and multithreaded applications run
correctly in Alpha and SPARC.
This frees up needed space for more public flags. Also:
- remove unused Request accessor methods
- make Packet use public Request accessors, so it need not be a friend
