The commit switches the kernel branch to r5 and updates the syscall bindings
in base-nova accordingly. Beside some cleanups, r5 extents the ec_ctrl syscall
to support following features:
* An EC may yield its current timeslice. The timeslice gets enqueued at the end
of the run queue without refreshing the left budget of the quantum.
* An EC helps with the current SC another EC. Used in Genode to implement
helping over a user-level lock to avoid live-lock situation. (Think of
a limited priority-inheritance mechanism.)
* An EC requests a new scheduler decision. Used in Genode to transfer back the
potentially helping SC to the helper EC.
Issue #986
For a main thread a thread object is created by the CRT0 before _main gets
called so that _main can already run in a generic environment that, e.g.,
catches stack overflows as a page-fault instead of corrupting the BSS.
Additionally dynamic programs have only one CRT0 - the one of the LDSO -
which does the initialization for both LDSO and program.
ref #989
Use a bit allocator for the allocation management of thread contexts,
instead of holding allocation information within the Thread_base objects,
which lead to race conditions in the past.
Moreover, extend the Thread_base class interface with the ability to
to add additional stacks to a thread, and associate the context they're
located in with the corresponding Thread_base object. Additional stacks
can be used to do user-level scheduling with stack switching, without breaking
Genode's API.
Fixes#1024Fixes#1036
Change the template parameter for Bit_allocator, and Bit_array. Instead of
assigning words to be used by the bit array, you can now tell the count of
items that shall be used.
Moreover, some dead code, previously using the Bit_allocator, was removed.
Related to #1024
Open a capability receive window according to the number of the capabilities
expected as out parameter per RPC function.
Typically the number of capabilities expected during the reply of a RPC/IPC
call is 0 to 1. Before this patch ever a capability receive window of 4 has
been opened.
On Nova the capability selectors of receive windows must be naturally aligned
to the size/order of the expected capabilities. This leads until now to the
issue that the left over 3 capabilities couldn't be reused for new IPCs since
they are not naturally aligned to 4.
Issue #905
If a local thread is attempted to be 'pause'd via cpu_session, don't wait
until it gets into the recalled state. If the caller is lucky it is, if not
return only the stack pointer.
Avoids deadlocking of the gdb when attached to a process running a server.
Issue #478
The 'pause' call on base-nova assumes that a thread can solely block in its
associated semaphore. Main reason is that so core can unblock a thread in order
that the recall exception gets delivered and the register state can be
obtained.
Unfortunately the signal session implementation creates a semaphore, which is
unknown by the pager code. Instead create the semaphore via the pager of the
thread, so that the pager can unblock the signal thread when a pause is issued.
Issue #478
If a thread caused a page fault and later on get be paused, then it left
the recall handler immediately due to the pause call instead of staying
in this handler.
Add some (complicated) state machine to detect and handle the case. Still not
waterproof, especially server threads may never get recalled if they never get
a IPC from the outside.
Fixes#478
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.
r3 contains the recent Nova upstream kernel version plus the Genode specific
extensions and changes as known from r2.
Additionally, the r3 branch
* contains the assign_pci patch now directly,
* adds support for cross CPU IPC,
* fixes some issues with freeing up kernel memory part of r2 and
* update the documentation a bit.
Fixes#814
Revoke the right to set the portal id (aka label) when it is not needed
anymore. Otherwise everybody in the system having a mapping of the portal can
reset the label to something we don't expect.
Issue #667
The distinction between 'ipc.h' and 'ipc_generic.h' is no more. The only
use case for platform-specific extensions of the IPC support was the
marshalling of capabilities. However, this case is accommodated by a
function interface ('_marshal_capability', '_unmarshal_capability'). By
moving the implementation of these functions from the headers into the
respective ipc libraries, we can abandon the platform-specific 'ipc.h'
headers.
The cleanup call must be performed already during the _dissolve function
shortly after the object at the cap_session is freed up. Otherwise there
is the chance that an in-flight IPC will find the to be dissolved function
again.
Bomb test triggered the case, that a already dissolved rpc_object was found
by a in-flight IPC. If the rpc_object was already freed up by alloc->destroy
the thread using this stale rpc_object pointer cause page-faults in core.
Fixes partly #549
If we ran out of capabilities indexes, the bit allocator throws an exception.
If this happens the code seems to hang and nothing happens.
Instead one could catch the exception and print some diagnostic message.
This would be nice, but don't work. Printing some diagnostic message itself
tries to do potentially IPC and will allocate new capability indexes at
least for the receive window.
So, catch the exception and let the thread die, so at least the instruction
pointer is left as trace to identify the reason of the trouble.
Fixes#625
