It's now possible to get purgeable memory by using mmap(MAP_PURGEABLE).
Purgeable memory has a "volatile" flag that can be set using madvise():
- madvise(..., MADV_SET_VOLATILE)
- madvise(..., MADV_SET_NONVOLATILE)
When in the "volatile" state, the kernel may take away the underlying
physical memory pages at any time, without notifying the owner.
This gives you a guilt discount when caching very large things. :^)
Setting a purgeable region to non-volatile will return whether or not
the memory has been taken away by the kernel while being volatile.
Basically, if madvise(..., MADV_SET_NONVOLATILE) returns 1, that means
the memory was purged while volatile, and whatever was in that piece
of memory needs to be reconstructed before use.
Using int was a mistake. This patch changes String, StringImpl,
StringView and StringBuilder to use size_t instead of int for lengths.
Obviously a lot of code needs to change as a result of this.
The main thread of each kernel/user process will take the name of
the process. Extra threads will get a fancy new name
"ProcessName[<tid>]".
Thread backtraces now list the thread name in addtion to tid.
Add the thread name to /proc/all (should it get its own proc
file?).
Add two new syscalls, set_thread_name and get_thread_name.
This patch adds these I/O counters to each thread:
- (Inode) file read bytes
- (Inode) file write bytes
- Unix socket read bytes
- Unix socket write bytes
- IPv4 socket read bytes
- IPv4 socket write bytes
These are then exposed in /proc/all and seen in SystemMonitor.
This defaults to 1500 for all adapters, but LoopbackAdapter increases
it to 65536 on construction.
If an IPv4 packet is larger than the MTU, we'll need to break it into
smaller fragments before transmitting it. This part is a FIXME. :^)
Turns out we can use abi::__cxa_demangle() for this, and all we need to
provide is sprintf(), realloc() and free(), so this patch exposes them.
We now have fully demangled C++ backtraces :^)
Previously it was not possible to see what each thread in a process was
up to, or how much CPU it was consuming. This patch fixes that.
SystemMonitor and "top" now show threads instead of just processes.
"ps" is gonna need some more fixing, but it at least builds for now.
Fixes#66.
Scheduling priority is now set at the thread level instead of at the
process level.
This is a step towards allowing processes to set different priorities
for threads. There's no userspace API for that yet, since only the main
thread's priority is affected by sched_setparam().
Add dedicated internal types for Int64 and UnsignedInt64. This makes it
a bit more straightforward to work with 64-bit numbers (instead of just
implicitly storing them as doubles.)
Previously, procfs$pid_fds would return nothing when called
for a process that had either no open files or a non-existent
handle. This could cause problems when a userspace program
expected a valid Json response.
Procfs$pid_fs now returns an empty array in the aforementioned
cases.
This patch adds three separate per-process fault counters:
- Inode faults
An inode fault happens when we've memory-mapped a file from disk
and we end up having to load 1 page (4KB) of the file into memory.
- Zero faults
Memory returned by mmap() is lazily zeroed out. Every time we have
to zero out 1 page, we count a zero fault.
- CoW faults
VM objects can be shared by multiple mappings that make their own
unique copy iff they want to modify it. The typical reason here is
memory shared between a parent and child process.
This is a freelist allocator with static size classes that works as a
complement to the generic kmalloc(). It's a lot faster than kmalloc()
since allocation just means popping from the freelist.
It's also significantly more compact when there are a lot of objects
smaller than the minimum kmalloc chunk size (32 bytes.)
This patch enables it for the Region and PhysicalPage classes.
In the PhysicalPage (8 bytes) case, it's a huge improvement since we
no longer waste 75% of the storage allocated.
There are also a number of ways this can be improved, so let's keep
working on it going forward.
The complication is around /proc/sys/ variables, which were attached
to inodes. Now they're their own thing, and the corresponding inodes
are lazily created (as all other ProcFS inodes are) and simply refer
to them by index.
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 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
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.
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.
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 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_.
