This patch introduces new types for expressing CPU affinities. Instead
of dealing with physical CPU numbers, affinities are expressed as
rectangles in a grid of virtual CPU nodes. This clears the way to
conveniently assign sets of adjacent CPUs to subsystems, each of them
managing their respective viewport of the coordinate space.
By using 2D Cartesian coordinates, the locality of CPU nodes can be
modeled for different topologies such as SMP (simple Nx1 grid), grids of
NUMA nodes, or ring topologies.
First make the clients inaccessible and dissolve them from the entrypoint. If
this isn't the first step the clients may be obtained again between
the unlock and lock steps in the destructor.
Additionally the clients may be removed in between the unlock and call
sequence, which renders such client pointers dangling and causes spurious page
faults. Keep instead a lock as long as possible and when it is required to
release a lock, then the pointer to the objects must be revalidated.
Replace the dissolve function with a remove_client implementation as suggested
by #13, which avoids that the cpu_session may call dissolve with a dangling
pointer of a already removed rm_client object. Instead the pager must be
released explicitly.
Related to issue #549
Related to issue #394
Related to issue #13
Add functionality to lookup an object and lock it. Additional the case is
handled that a object may be already in-destruction and the lookup will deny
returning the object.
The object_pool generalize the lookup and lock functionality of the rpc_server
and serve as base for following up patches to fix dangling pointer issues.
The CPU session interfaces comes with the ability to install an
exception handler per thread. This patch enhances the feature with the
provision of a default signal handler that is used if no thread-specific
handler is installed. The default signal handler can be set by
specifying an invalid thread capability and a valid signal context
capability.
Furthermore, this patch relaxes the requirement of the order of the
calls of 'exception_handler' and 'set_pager'. Originally, the exception
handler could be installed not before setting a pager. Now, we remember
the installed exception handler in the 'Cpu_thread' and propagate to to
the platform thread at a later time.
This patch introduces the functions 'affinity' and 'num_cpus' to the CPU
session interface. The interface extension will allow the assignment of
individual threads to CPUs. At this point, it is just a stub with no
actual platform support.
Norman Feske
Alexander Boettcher
Christian Prochaska
Martin Stein
Genode Labs