bunnie 8d7065d741 implement hard-OOM handler ... A hard-OOM is what happens when the allocator really runs out of memory. To review, there are two types of OOMs handled by the swapper: - "OOM Doom": impending OOM. This is detected by a userspace process that can do more sophisticated processing and algorithms to predict an impending OOM. The OOM Doom handler is also interruptable, which allows other progresses to make progress while memory is being cleared up, hopefully allowing for a more graceful failure curve. - "Hard OOM": Literally no more pages are available. This is triggered when the page allocator can't map a single more page. The hard-OOM handler turns off all interrupts, and all the OOM process happens within the uninterruptable userspace context. This effectively turns the OOM handler "inside out" compared to the normal, interruptable userspace handler. In order to support this, a set of calls that implement the kernel space pre-amble and post-amble (i.e. StealPage and ReleaseMemory) are introduced. This does introduce an extra edge case in the exit path of the hard-OOM, namely, if the hard-OOM failed on a page that was swapped. Here, after clearing memory, we have an empty page, but no data; we have to again re-enter the userspace handler to fill that page. The twist here is we have to remember to re-instate interrupts on this edge case otherwise we lose pre-emption.		2024-05-21 01:13:13 +08:00
..
arch	improve debug output on entry/exit from irqs	2024-05-21 01:11:58 +08:00
debug	ok, format the kernel now that all in-line assembly has been checked	2024-01-14 19:27:14 +08:00
platform	update comments and add license headers	2024-05-13 14:21:53 +08:00
args.rs	ok, format the kernel now that all in-line assembly has been checked	2024-01-14 19:27:14 +08:00
io.rs	allow this trait to be unused	2024-05-10 00:38:41 +08:00
irq.rs	upgrade irq path to handle the new API	2024-03-23 11:59:31 +08:00
macros.rs
main.rs	move MinSet to utils so that we can test it	2024-05-18 00:22:50 +08:00
mem.rs	add hooks to hard-oom handler in the alloc_page_oomable routine	2024-05-21 01:07:13 +08:00
server.rs	ok, format the kernel now that all in-line assembly has been checked	2024-01-14 19:27:14 +08:00
services.rs	cleanup some warnings in other targets	2024-05-18 00:28:11 +08:00
swap.rs	implement hard-OOM handler	2024-05-21 01:13:13 +08:00
syscall.rs	add syscalls for "inverse" OOM'er	2024-05-21 01:03:42 +08:00
test.rs	add unit test for MinSet / renormalization	2024-05-18 00:24:01 +08:00
utils.rs	move MinSet to utils so that we can test it	2024-05-18 00:22:50 +08:00