In order to be functional and avoid linker errors, use a
default setting for BACKING_STORE_CHOICE that is something other
than "this is not implemented".
Signed-off-by: Chris Friedt <cfriedt@tenstorrent.com>
With assert condition set to true, assertion never happens.
Change __ASSERT(true) to __ASSERT(false).
Signed-off-by: Dmitry Lukyantsev <dmitrylu@meta.com>
This provides memory mappings with the ability to be initialized in their
paged-out state and be paged in on demand. This is especially nice for
anonymous memory mappings as they no longer have to allocate all memory
at mem_map time. This also allows for file mappings to be implemented by
simply providing backing store location tokens.
Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
First, do align the buffer. The slab code puts pointers in there and it
does not like it if those are not properly aligned.
And return the actual error code from k_mem_slab_alloc() even if errors
shouldn't happen (it did happen to me because of the above ... with
assertions disabled).
Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
Also any demand paging and page frame related bits are
renamed.
This is part of a series to move memory management related
stuff out of the Z_ namespace into its own namespace.
Signed-off-by: Daniel Leung <daniel.leung@intel.com>
This is part of a series to move memory management related
stuff from Z_ namespace into its own namespace.
Signed-off-by: Daniel Leung <daniel.leung@intel.com>
Introduce z_page_frame_set() and z_page_frame_clear() to manipulate
flags. Obtain the virtual address using the existing
z_page_frame_to_virt(). This will make changes to the page frame
structure easier.
Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
This moves including of demand_paging.h out of kernel/mm.h,
so that users of demand paging APIs must include the header
explicitly. Since the main user is kernel itself, we can be
more discipline about header inclusion.
Signed-off-by: Daniel Leung <daniel.leung@intel.com>
Modify the signature of the k_mem_slab_free() function with a new one,
replacing the old void **mem with void *mem as a parameter.
The following function:
void k_mem_slab_free(struct k_mem_slab *slab, void **mem);
has the wrong signature. mem is only used as a regular pointer, so there
is no need to use a double-pointer. The correct signature should be:
void k_mem_slab_free(struct k_mem_slab *slab, void *mem);
The issue with the current signature, although functional, is that it is
extremely confusing. I myself, a veteran Zephyr developer, was confused
by this parameter when looking at it recently.
All in-tree uses of the function have been adapted.
Fixes#61888.
Signed-off-by: Carles Cufi <carles.cufi@nordicsemi.no>
In order to bring consistency in-tree, migrate all subsystems code to
the new prefix <zephyr/...>. Note that the conversion has been scripted,
refer to zephyrproject-rtos#45388 for more details.
Signed-off-by: Gerard Marull-Paretas <gerard.marull@nordicsemi.no>
This adds a flash-based backing store for qemu_x86_tiny board for
testing demand paging. This allows us to test code execution where
.text section is not in physical memory at boot.
Signed-off-by: Daniel Leung <daniel.leung@intel.com>
These functions are those that need be implemented by backing
store outside kernel. Promote them from z_* so these can be
included in documentation.
Signed-off-by: Daniel Leung <daniel.leung@intel.com>
If we evict enough pages to completely fill the backing store,
through APIs like k_mem_map(), z_page_frame_evict(), or
z_mem_page_out(), this will produce a crash the next time we
try to handle a page fault.
The backing store now always reserves a free storage location
for actual page faults.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
Backing stores and eviction algorithms will be included here.
Exactly one must be chosen, with a default option to leave
the implementation to the application.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
If we evict enough pages to completely fill the backing store,
through APIs like k_mem_map(), z_page_frame_evict(), or
z_mem_page_out(), this will produce a crash the next time we
try to handle a page fault.
The backing store now always reserves a free storage location
for actual page faults.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
Backing stores and eviction algorithms will be included here.
Exactly one must be chosen, with a default option to leave
the implementation to the application.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
