written the page, we now do it before, so that it cannot lose any changed data
anymore; it doesn't matter if the page is written to while writing it back, the
worst thing that can happen is that we write the same page twice. Also, we don't
rely on the PAGE_MODIFIED bit anymore, we now check all mappings of that page
to find all modified pages, no matter how far the (currently disabled) page
daemon had come.
Also, destroying an area will now result in writing back changed pages - this
is only really important for memory mapped files, though, and should probably
be avoided for other vm_store types.
Minor cleanup.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@15597 a95241bf-73f2-0310-859d-f6bbb57e9c96
memory status.
Added new B_NO_LOW_MEMORY constant for the usual case.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@15551 a95241bf-73f2-0310-859d-f6bbb57e9c96
has not yet been tested, though - I'll do this after this commit):
* Removed the arch_memory_type stuff from vm_area; since there are only 8 memory
ranges on x86, it's simply overkill. The MTRR code now remembers the area ID
and finds the MTRR that way (it could also iterate over the existing MTRRs).
* Introduced some post_modules() init functions.
* If the other x86 CPUs out there don't differ a lot, MTRR functionality might
be put back into the kernel.
* x86_write_msr() was broken, it wrote the 64 bit number with the 32 bit words
switched - it took me some time (and lots of #GPs) to figure that one out.
* Removed the macro read_ebp() and introduced a function x86_read_ebp()
(it's not really a time critical call).
* Followed the Intel docs on how to change MTRRs (symmetrically on all CPUs
with caches turned off).
* Asking for memory types will automatically change the requested length to
a power of two - note that BeOS seems to behave in the same, although that's
not really very clean.
* fixed MTRRs are ignored for now - we should make sure at least, though,
that they are identical on all CPUs (or turn them off, even though I'd
prefer the BIOS stuff to be uncacheable, which we don't enforce yet, though).
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sends a SIGSEGV signal (and lets the debugger handle the rest).
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There, we need to detect the modified state from the mapping, too - the
vm_page state itself might not be up to date.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@14049 a95241bf-73f2-0310-859d-f6bbb57e9c96
pages, ie. they considered the areas to be B_LAZY_LOCK. But that doesn't really make
sense and potentially cause page faults where you wouldn't expect them (and where
it's not a good idea to trigger them).
Reworked display_mem() (used by the dw/db/ds commands in the kernel debugger) to
be a bit more sane, improved formatting, and allows it to work on non-existing
memory without a panic.
The "area" debugger command now also accepts an address (contained by the area)
as argument - and it will now always print out an error message if no matching
area could be found.
Replaced all dprintf() calls to kprintf() calls for the kernel debugger functions.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@14042 a95241bf-73f2-0310-859d-f6bbb57e9c96
only a read lock on the inode, or without a lock at all (in case of prefetching) - it
is now using the cache_ref's lock to make sure it's retrieved only once and doesn't
waste/corrupts any memory.
- since that fix made it mandatory to fix write_chunk_into_cache() to not call pages_io()
while holding the cache_ref's lock (was a to-do item before), I changed it to make
that possible.
- It now also supports write-through caches in theory - as there is no way yet to tell
a cache to work this way.
- Optimized for the not so uncommon case of writing the last part of a file that is not
a multiple of the page size - it won't call pages_io() anymore then, but zero the rest
of the page directly.
- vm_page_write_modified() is now calling write_page() without holding the cache_ref's
lock as well.
The updated write_chunk_to_cache() is not so well tested, though, but appears to work
so far.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@14006 a95241bf-73f2-0310-859d-f6bbb57e9c96
prevents the system to allocate caches for files that don't use or have
a file cache (ie. only those can be mmap()ed!).
Therefore, cache_prefetch() no longer crashes when trying to prefetch
files without a file cache.
read_into_cache() no longer does anything if the requested size is 0.
Fixed a bug in cache_prefetch_vnode(): if the cache couldn't be retrieved,
it put the vnode, but didn't own it (the caller does).
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@13904 a95241bf-73f2-0310-859d-f6bbb57e9c96
Removed vfs_vnode_release_ref(), as vfs_put_vnode() already does the same thing.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@13867 a95241bf-73f2-0310-859d-f6bbb57e9c96
into account when remapping the pages read-only; it could have overwritten valid
page mappings this way. This was also the reason for the Terminal to crash - it
does now work as it should, although some keys don't work (like tab completion)).
vm_copy_area() no longer always sets B_KERNEL_WRITE_AREA if no kernel protection
was specified, but mirrors the userland protection (for example, the x86 MMU is
not able to have a page writable in kernel but not in userland). This caused
some areas to be read/write when read-only would have been enough.
vm_copy_area() now panics when vm_copy_on_write_area() fails - that's of course
no real solution, but it's bettern than letting it silently fail.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@13768 a95241bf-73f2-0310-859d-f6bbb57e9c96
time of the idle thread. IOW Pulse now works :-)
Renamed the idle thread/stack to start with 1 instead of 0 (first idle thread will
be called "idle thread 1").
Minor cleanup.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@13373 a95241bf-73f2-0310-859d-f6bbb57e9c96
will return true in the former case).
vm_delete_areas() is now using this information to print out a warning
in this case (so that a missing vm_put_area() can now be found easier).
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@12693 a95241bf-73f2-0310-859d-f6bbb57e9c96
following 1152 MB - that area only guarantees that the heap can grow this much before
the application need the memory for something else. And even then, the heap range
is reused from top-to-bottom, allowing for maximum heap usage. Of course, if the
memory after the heap range is not claimed yet, it can still be claimed by the heap,
too. Added new syscall to create the reserved range.
Fixed a bug in vm_delete_areas(): when it removed reserved areas, the area list
could get messed up.
Fixed a bug in resize_area(): resized areas could never be deleted (missing vm_put_area())!
resize_area() now supports reserved regions (but not perfectly yet, see ToDo items).
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@12692 a95241bf-73f2-0310-859d-f6bbb57e9c96
only if memory becomes tight, and then the range is used from end to
start.
This is useful to reserve heap address ranges.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@12675 a95241bf-73f2-0310-859d-f6bbb57e9c96
along the protection flags).
Changed the handling of B_STACK_AREA types and anonymous vm_areas: now
every area can overcommit if B_OVERCOMMITTING_AREA was specified.
B_STACK_AREA areas are still automatically overcommitting, but
B_KERNEL_STACK_AREA areas no longer.
vm_store_anonymous_noswap.c now only tests for guard pages if there were
any specified which is only done for B_STACK_AREA areas.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@12673 a95241bf-73f2-0310-859d-f6bbb57e9c96
If anything is still broken (and was not before :)), please shout.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@12361 a95241bf-73f2-0310-859d-f6bbb57e9c96
