Commit graph

8 commits

Author SHA1 Message Date
Ben Gras
f78d8e74fd secondary cache feature in vm.
A new call to vm lets processes yield a part of their memory to vm,
together with an id, getting newly allocated memory in return. vm is
allowed to forget about it if it runs out of memory. processes can ask
for it back using the same id. (These two operations are normally
combined in a single call.)

It can be used as a as-big-as-memory-will-allow block cache for
filesystems, which is how mfs now uses it.
2010-05-05 11:35:04 +00:00
Ben Gras
c78250332d let vm use physically fragmented memory for allocations.
map_copy_ph_block is replaced by map_clone_ph_block, which can
replace a single physical block by multiple physical blocks.

also,
 . merge map_mem.c with region.c, as they manipulate the same
   data structures
 . NOTRUNNABLE removed as sanity check
 . use direct functions for ALLOC_MEM and FREE_MEM again
 . add some checks to shared memory mapping code
 . fix for data structure integrity when using shared memory
 . fix sanity checks
2010-04-12 11:25:24 +00:00
David van Moolenbroek
61bb82a44b VM information interface 2010-01-19 21:00:20 +00:00
Ben Gras
32fbbd370c - pages that points to page directory values of all processes,
shared with the kernel, mapped into kernel address space; 
   kernel is notified of its location. kernel segment size is
   increased to make it fit.
 - map in kernel and other processes that don't have their
   own page table using single 4MB (global) mapping.
 - new sanity check facility: objects that are allocated with
   the slab allocator are, when running with sanity checking on,
   marked readonly until they are explicitly unlocked using the USE()
   macro.
 - another sanity check facility: collect all uses of memory and
   see if they don't overlap with (a) eachother and (b) free memory
 - own munmap() and munmap_text() functions.
 - exec() recovers from out-of-memory conditions properly now; this
   solves some weird exec() behaviour
 - chew off memory from the same side of the chunk as where we
   start scanning, solving some memory fragmentation issues
 - use avl trees for freelist and phys_ranges in regions
 - implement most useful part of munmap()
 - remap() stuff is GQ's for shared memory
2009-09-21 14:49:49 +00:00
Ben Gras
2dd02cc560 mark pages whose refcount were >1 and drop to 1 and are
read/write writable in the pagetable right away instead of waiting for
a pagefault. minor optimization.

some a sanity check of SLAB-allocated pointers.

vm gets its own _exit and __exit like PM, so the stock (library) panic works.
2009-04-22 12:39:29 +00:00
Ben Gras
3121eec6bd . map text (kernel's and processes') in readonly
. map kernel in non-user
 . don't map in first pages of kernel code and data
   if possible

these first pages could actually be freed but as the
kernel isn't allowed to touch them either we can't reuse
them until VM has totally taken over page table management
and kernel doesn't rely on identity mapping any more.
2008-12-18 15:35:22 +00:00
Ben Gras
68d0c4defe - code shared with exec() letting boot-time processes have
their own fully fledged virtual address space and freeing
   their pre-allocated heap+stack area (necessary to let memory
   driver map in arbitrary areas of memory for /dev/mem without
   sys_vm_map)
 - small optimization preallocating memory on exec
 - finished VR_DIRECT physical mapping code
2008-12-08 16:43:20 +00:00
Ben Gras
c078ec0331 Basic VM and other minor improvements.
Not complete, probably not fully debugged or optimized.
2008-11-19 12:26:10 +00:00