This replaces Optional<T>(U&&) which clang-tidy complained may hide the
regular copy and move constructors. That's a good point, clang-tidy,
and I appreciate you pointing that out!
Remove the global hash tables and replace them with InlineLinkedLists.
This significantly reduces the kernel heap pressure from doing many
small mmap()'s.
Using a HashTable to track "all instances of Foo" is only useful if we
actually need to look up entries by some kind of index. And since they
are HashTable (not HashMap), the pointer *is* the index.
Since we have the pointer, we can just use it directly. Duh.
This increase sizeof(VMObject) by two pointers, but removes a global
table that had an entry for every VMObject, where the cost was higher.
It also avoids all the general hash tabling business when creating or
destroying VMObjects. Generally we should do more of this. :^)
This is a very simple version of the nc (netcat) command. It only
supports outgoing TCP connections, and has no options aside from the
target host and port.
This is comprised of five small changes:
* Keep a counter for tx/rx packets/bytes per TCP socket
* Keep a counter for tx/rx packets/bytes per network adapter
* Expose that data in /proc/net_tcp and /proc/netadapters
* Convert /proc/netadapters to JSON
* Fix up ifconfig to read the JSON from netadapters
When assigning properties, we were relying on the JSON serialization
code to wrap strings in double-quotes ("). JsonValue::to_string() does
not wrap string values, so what we want here is serialized(). :^)
This broke due to a change in JsonValue API. JsonValue::to_string() now
returns the value serialized to a string, which may become "undefined".
You kinda want JsonValue::as_string(), but that is only callable when
the JsonValue *is* a string. Thankfully there is now as_string_or(alt).
We were only doing this in Process::deallocate_region(), which meant
that kernel-only Regions never gave back their VM.
With this patch, we can start reusing freed-up address space! :^)
This is not perfect as it uses a lot of VM, but since the buffers are
supposed to be temporary it's not super terrible.
This could be improved by giving back the unused VM to the kernel's
RangeAllocator after finishing the buffer building.
Each Function is a heap allocation, so let's make an effort to avoid
doing that during scheduling. Because of header dependencies, I had to
put the runnables iteration helpers in Thread.h, which is a bit meh but
at least this cuts out all the kmalloc() traffic in pick_next().
If kmalloc backtraces are enabled during backtracing, things don't go
super well when the backtrace code calls kmalloc()..
With this fixed, it's basically possible to get all kmalloc backtraces
on the debugger by running (as root):
sysctl kmalloc_stacks=1
This makes VMObject 8 bytes smaller since we can use the array size as
the page count.
The size() is now also computed from the page count instead of being
a separate value. This makes sizes always be a multiple of PAGE_SIZE,
which is sane.
InodeVMObject is a VMObject with an underlying Inode in the filesystem.
AnonymousVMObject has no Inode.
I'm happy that InodeVMObject::inode() can now return Inode& instead of
VMObject::inode() return Inode*. :^)
This wasn't really thought-through, I was just trying anything to see
if it would make WindowServer faster. This doesn't seem to make much of
a difference either way, so let's just not do it for now.
It's easy to bring back if we think we need it in the future.
The VMObject name was always either the owning region's name, or the
absolute path of the underlying inode.
We can reconstitute this information if wanted, no need to keep copies
of these strings around.
This allows us to take advantage of the now-optimized (to do memmove())
Vector::append(const T*, int count) for collecting these strings.
This is a ~15% speedup on the load_4chan_catalog benchmark.
This can definitely be improved with better trivial type detection and
by using the TypedTransfer template in more places.
It's a bit annoying that we can't get <type_traits> in Vector.h since
it's included in the toolchain compilation before we have libstdc++.
This class works by eagerly allocating 1MB of virtual memory but only
adding physical pages on demand. In other words, when you append to it,
its memory usage will increase by 1 page whenever you append across a
page boundary (4KB.)
Instead of dumping the dying thread's backtrace in the signal handling
code, wait until we're finalizing the thread. Since signalling happens
during scheduling, the less work we do there the better.
Basically the less that happens during a scheduler pass the better. :^)
This has several significant changes to the networking stack.
* Significant refactoring of the TCP state machine. Right now it's
probably more fragile than it used to be, but handles quite a lot
more of the handshake process.
* `TCPSocket` holds a `NetworkAdapter*`, assigned during `connect()` or
`bind()`, whichever comes first.
* `listen()` is now virtual in `Socket` and intended to be implemented
in its child classes
* `listen()` no longer works without `bind()` - this is a bit of a
regression, but listening sockets didn't work at all before, so it's
not possible to observe the regression.
* A file is exposed at `/proc/net_tcp`, which is a JSON document listing
the current TCP sockets with a bit of metadata.
* There's an `ETHERNET_VERY_DEBUG` flag for dumping packet's content out
to `kprintf`. It is, indeed, _very debug_.
KBuffers are now zero-filled on demand instead of up front. This means
that you can create a huge KBuffer and it will only take up VM, not
physical pages (until you access them.)
We were short-circuiting the page fault handler a little too eagerly
for page-not-present faults in kernel memory.
If the current page directory already has up-to-date mapps for kernel
memory, allow it to progress to checking for zero-fill conditions.
This will enable us to have lazily populated kernel regions.
