vasilito
4789d546e2
Wire up three new ContextHandle variants and their /proc/<pid>/{name,
sched-policy, priority} paths so that userspace (libredox, relibc's
pthread_setname_np / pthread_setschedparam / setpriority) can read
and write these per-context fields.
Changes:
ContextHandle enum (proc.rs:103-153):
- Add SchedPolicy (write: [policy, rt_priority] u8,u8;
read: [policy, rt_priority] u8,u8)
- Add Name (write: up-to-32-byte UTF-8 string, NUL-trimmed;
read: the stored ArrayString bytes)
- Add Priority (write: i32 nice value, range-checked to -20..=19;
read: i32 nice value computed from context.prio)
openat_context paths (proc.rs:251-254):
- 'sched-policy' -> ContextHandle::SchedPolicy
- 'name' -> ContextHandle::Name
- 'priority' -> ContextHandle::Priority
Attr write handler (proc.rs:1286):
- Switched from 'guard.prio = (info.prio as usize).min(39)'
to 'guard.set_sched_other_prio(info.prio as usize)' so that
both prio AND sched_static_prio are kept in sync. Previously
sched_static_prio (used by the DWRR weight table) was never
updated from userspace, so the kernel's fair-scheduling
weight stayed at the initial value forever.
Combined with the prior commit 'add Context::set_sched_policy and
set_sched_other_prio', this completes the userspace API for
threading control:
- pthread_setname_np -> /proc/<tid>/name
- sched_setscheduler -> /proc/<tid>/sched-policy
- setpriority / nice -> /proc/<tid>/priority
- pthread_setschedparam -> /proc/<tid>/sched-policy + /proc/<tid>/priority
cargo check: now exits 0 with 0 errors. 37 warnings remain (all
pre-existing, none blocking).
Upstream check: verified via the bg_27f3578a audit that upstream
Redox kernel has NONE of these features; the local fork is the
sole implementation.
Kernel
Redox OS Microkernel
Requirements
nasmneeds to be available on the PATH at build time.
Building The Documentation
Use this command:
cargo doc --open --target x86_64-unknown-none
Debugging
QEMU
Running QEMU with the -s flag will set up QEMU to listen on port 1234 for a GDB client to connect to it. To debug the redox kernel run.
make qemu gdb=yes
This will start a virtual machine with and listen on port 1234 for a GDB or LLDB client.
GDB
If you are going to use GDB, run these commands to load debug symbols and connect to your running kernel:
(gdb) symbol-file build/kernel.sym
(gdb) target remote localhost:1234
LLDB
If you are going to use LLDB, run these commands to start debugging:
(lldb) target create -s build/kernel.sym build/kernel
(lldb) gdb-remote localhost:1234
After connecting to your kernel you can set some interesting breakpoints and continue
the process. See your debuggers man page for more information on useful commands to run.
Notes
-
Always use
foo.get(n)instead offoo[n]and try to cover for the possibility ofOption::None. Doing the regular way may work fine for applications, but never in the kernel. No possible panics should ever exist in kernel space, because then the whole OS would just stop working. -
If you receive a kernel panic in QEMU, use
pkill qemu-systemto kill the frozen QEMU process.
How To Contribute
To learn how to contribute to this system component you need to read the following document:
Development
To learn how to do development with this system component inside the Redox build system you need to read the Build System and Coding and Building pages.
How To Build
To build this system component you need to download the Redox build system, you can learn how to do it on the Building Redox page.
This is necessary because they only work with cross-compilation to a Redox virtual machine, but you can do some testing from Linux.
Funding - Unix-style Signals and Process Management
This project is funded through NGI Zero Core, a fund established by NLnet with financial support from the European Commission's Next Generation Internet program. Learn more at the NLnet project page.
