Turn Genode user-level spinlock into a user-level "helpinglock". This requires
support by the kernel introduced with kernel branch r5.
The commit avoids live-locks when multiple threads with SCs on different
priority levels compete for the same user-level Genode "spinlock".
Issue #986
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
Otherwise affinity space is set to 1x1 and in cpu_session_component.cc the cpu
session local affinity space defined by parent is not taken because
"Location::valid()" returns true.
Issue #1107
* Core_mem_allocator: implement Range_allocator interface
* Core_mem_allocator: allocate with page-granularity only
* Use slab allocators in core where meaningful (e.g. dataspace objects)
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
Fail hard if no large enough virtual memory area can be found where to map
the memory from the kernel to core.
Additionally clear dataspaces in junks if it can't be done in one large junk.
Fixes#1011
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
To prevent multiple execution of main-bootstrap, I moved the code to a
statically initialized object. The reason for this change is that
_main() is exeuted twice when starting dynamic binaries. Now, the object
is part of the base-common library which is linked with ld.lib.so.
Alexander Boettcher
Stefan Kalkowski
Christian Helmuth
Martin Stein
Christian Prochaska
Norman Feske