Linuxulator is x86 only.
The only notable differences in algnment for an LP64 64-bit system
when compared to a 32-bit system is an eight or large byte types
alignment.
MFC after: 1 month
- Optimise the RCU implementation to not allocate and free
ck_epoch_records during runtime. Instead allocate two sets of
ck_epoch_records per CPU for general purpose use. The first set is
only used for reader locks and the second set is only used for
synchronization and barriers and is protected with a regular mutex to
prevent simultaneous issues.
- Move the task structure away from the rcu_head structure and into
the per-CPU structures. This allows the size of the rcu_head structure
to be reduced down to the size of two pointers.
- Fix a bug where the linux_rcu_barrier() function only waited for one
per-CPU epoch record to be completed instead of all.
- Use a critical section or a mutex to protect ck_epoch_begin() and
ck_epoch_end() depending on RCU or SRCU type. All the ck_epoch_xxx()
functions, except ck_epoch_register(), ck_epoch_unregister() and
ck_epoch_recycle() are not re-entrant and needs a critical section or
a mutex to operate in the LinuxKPI, after inspecting the CK
implementation of the above mentioned functions. The simultaneous
issues arise from per-CPU epoch records being shared between multiple
threads depending on the amount of taskswitching and how many threads
are involved with the RCU and SRCU operations.
- Properly free all epoch records by using safe list traversal at
LinuxKPI module unload. It turns out the ck_epoch_recycle() always
have the records on an internal list and use a flag in the epoch
record to track allocated and free entries. This would lead to use
after free during module unload.
- Remove redundant synchronize_rcu() call from the
linux_compat_uninit() function. Let the linux_rcu_runtime_uninit()
function do the final rcu_barrier() instead.
MFC after: 1 week
Sponsored by: Mellanox Technologies
The clang compiler will optimise these functions down to three AMD64
instructions if the bit argument is a constant during compilation.
MFC after: 1 week
Sponsored by: Mellanox Technologies
When allocating unmapped pages, take advantage of the direct map on
AMD64 to get the virtual address corresponding to a page. Else all
pages allocated must be mapped because sometimes the virtual address
of a page is requested.
Move all page allocation and deallocation code into an own C-file.
Add support for GFP_DMA32, GFP_KERNEL, GFP_ATOMIC and __GFP_ZERO
allocation flags.
Make a clear separation between mapped and unmapped allocations.
Obtained from: kmacy @
MFC after: 1 week
Sponsored by: Mellanox Technologies
The i915kms driver in Linux 4.9 reimplement parts of the scatter list
functions with regards to performance. In other words there is not so
much room for changing structure layouts and functionality if the
i915kms should be built AS-IS. This patch aligns the scatter list
support to what is expected by the i915kms driver. Remove some
comments not needed while at it.
Obtained from: kmacy @
MFC after: 1 week
Sponsored by: Mellanox Technologies
would be useless anyway - there is no point in pretending to have block
devices; our "block" devices are in fact character ones, and can only
be accessed as such.
Discussed with: dchagin
MFC after: 2 weeks
Sponsored by: DARPA, AFRL
1) Add better spinlock debug names when WITNESS_ALL is defined.
2) Make sure that the calling thread gets bound to the current CPU
while a spinlock is locked. Some Linux kernel code depends on that the
CPU ID doesn't change while a spinlock is locked.
3) Add support for using LinuxKPI spinlocks during a panic().
MFC after: 1 week
Sponsored by: Mellanox Technologies
Tasklets are implemented using a taskqueue and a small statemachine on
top. The additional statemachine is required to ensure all LinuxKPI
tasklets get serialized. FreeBSD taskqueues do not guarantee
serialisation of its tasks, except when there is only one worker
thread configured.
MFC after: 1 week
Sponsored by: Mellanox Technologies
A set of helper functions have been added to manage the life of the
LinuxKPI task struct. When an external system call or task is invoked,
a check is made to create the task struct by demand. A thread
destructor callback is registered to free the task struct when a
thread exits to avoid memory leaks.
This change lays the ground for emulating the Linux kernel more
closely which is a dependency by the code using the LinuxKPI APIs.
Add new dedicated td_lkpi_task field has been added to struct thread
instead of abusing td_retval[1].
Fix some header file inclusions to make LINT kernel build properly
after this change.
Bump the __FreeBSD_version to force a rebuild of all kernel modules.
MFC after: 1 week
Sponsored by: Mellanox Technologies
parameter to mmap(2), even if MAP_FIXED is not explicitly specified.
Android ART is one example. Implement bug compatibility for this case
in linuxulator.
Reviewed by: dchagin@
MFC after: 2 weeks
Sponsored by: DARPA, AFRL
Differential Revision: https://reviews.freebsd.org/D9373
Convert linux_recv(), linux_send() and linux_accept() system call arguments
to the register_t type too.
PR: 217161
MFC after: 3 days
xMFC with: r313284,r313285,r313684
