RedBear-OS/local/patches/kernel/absorbed/P6-vruntime-context.patch

diff --git a/src/context/context.rs b/src/context/context.rs
index c97c516..a0814fa 100644
--- a/src/context/context.rs
+++ b/src/context/context.rs
@@ -18,7 +18,8 @@ use crate::{
     cpu_stats,
     ipi::{ipi, IpiKind, IpiTarget},
     memory::{
-        allocate_p2frame, deallocate_p2frame, Enomem, Frame, RaiiFrame, RmmA, RmmArch, PAGE_SIZE,
+        allocate_p2frame, deallocate_p2frame, Enomem, Frame, PhysicalAddress, RaiiFrame, RmmA,
+        RmmArch, PAGE_SIZE,
     },
     percpu::PercpuBlock,
     scheme::{CallerCtx, FileHandle, SchemeId},
@@ -62,6 +63,38 @@ impl Status {
     }
 }
 
+pub const SCHED_PRIORITY_LEVELS: usize = 40;
+pub const DEFAULT_SCHED_OTHER_PRIORITY: usize = 20;
+pub const DEFAULT_SCHED_RR_QUANTUM: u128 = 100_000_000;
+
+#[repr(u8)]
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+pub enum SchedPolicy {
+    Fifo = 0,
+    RoundRobin = 1,
+    Other = 2,
+}
+
+impl SchedPolicy {
+    pub fn try_from_raw(raw: u8) -> Option<Self> {
+        match raw {
+            0 => Some(Self::Fifo),
+            1 => Some(Self::RoundRobin),
+            2 => Some(Self::Other),
+            _ => None,
+        }
+    }
+}
+
+pub fn rt_priority_to_kernel_prio(rt_priority: u8) -> usize {
+    (SCHED_PRIORITY_LEVELS - 1)
+        .saturating_sub((usize::from(rt_priority.min(99)) * (SCHED_PRIORITY_LEVELS - 1)) / 99)
+}
+
+fn clamp_sched_other_prio(prio: usize) -> usize {
+    prio.min(SCHED_PRIORITY_LEVELS - 1)
+}
+
 #[derive(Clone, Debug)]
 pub enum HardBlockedReason {
     /// "SIGSTOP", only procmgr is allowed to switch contexts this state
@@ -140,6 +173,20 @@ pub struct Context {
     pub fmap_ret: Option<Frame>,
     /// Priority
     pub prio: usize,
+    pub sched_policy: SchedPolicy,
+    pub sched_rt_priority: u8,
+    pub sched_rr_ticks_consumed: u32,
+    pub sched_static_prio: usize,
+pub sched_rr_quantum: u128,
+    /// Virtual runtime for SCHED_OTHER fair scheduling.
+    /// CPU-bound threads accumulate vruntime faster; I/O-bound stay lower.
+    pub vruntime: u128,
+    #[allow(dead_code)]
+    pub futex_pi_boost: bool,
+    #[allow(dead_code)]
+    pub futex_pi_original_prio: usize,
+    #[allow(dead_code)]
+    pub futex_pi_waiters: Vec<PhysicalAddress>,
 
     // TODO: id can reappear after wraparound?
     pub owner_proc_id: Option<NonZeroUsize>,
@@ -148,6 +195,8 @@ pub struct Context {
     pub euid: u32,
     pub egid: u32,
     pub pid: usize,
+    /// Supplementary group IDs for access control decisions.
+    pub groups: Vec<u32>,
 
     // See [`PreemptGuard`]
     //
@@ -197,13 +246,23 @@ impl Context {
             files: Arc::new(RwLock::new(FdTbl::new())),
             userspace: false,
             fmap_ret: None,
-            prio: 20,
+            prio: DEFAULT_SCHED_OTHER_PRIORITY,
+            sched_policy: SchedPolicy::Other,
+            sched_rt_priority: 0,
+            sched_rr_ticks_consumed: 0,
+            sched_static_prio: DEFAULT_SCHED_OTHER_PRIORITY,
+            sched_rr_quantum: DEFAULT_SCHED_RR_QUANTUM,
+            vruntime: 0u128,
+            futex_pi_boost: false,
+            futex_pi_original_prio: DEFAULT_SCHED_OTHER_PRIORITY,
+            futex_pi_waiters: Vec::new(),
             being_sigkilled: false,
             owner_proc_id,
 
             euid: 0,
             egid: 0,
             pid: 0,
+            groups: Vec::new(),
 
             #[cfg(feature = "syscall_debug")]
             syscall_debug_info: crate::syscall::debug::SyscallDebugInfo::default(),
@@ -218,11 +277,47 @@ impl Context {
         self.preempt_locks == 0
     }
 
+    fn base_sched_prio(&self) -> usize {
+        match self.sched_policy {
+            SchedPolicy::Other => clamp_sched_other_prio(self.sched_static_prio),
+            SchedPolicy::Fifo | SchedPolicy::RoundRobin => {
+                rt_priority_to_kernel_prio(self.sched_rt_priority)
+            }
+        }
+    }
+
+    fn apply_sched_prio(&mut self) {
+        let base_prio = self.base_sched_prio();
+        if self.futex_pi_boost {
+            self.futex_pi_original_prio = base_prio;
+            self.prio = self.prio.min(base_prio);
+        } else {
+            self.futex_pi_original_prio = base_prio;
+            self.prio = base_prio;
+        }
+    }
+
+    pub fn set_sched_other_prio(&mut self, prio: usize) {
+        self.sched_static_prio = clamp_sched_other_prio(prio);
+        self.apply_sched_prio();
+    }
+
+    pub fn set_sched_policy(&mut self, sched_policy: SchedPolicy, rt_priority: u8) {
+        self.sched_policy = sched_policy;
+        self.sched_rt_priority = match sched_policy {
+            SchedPolicy::Other => 0,
+            SchedPolicy::Fifo | SchedPolicy::RoundRobin => rt_priority.min(99),
+        };
+        self.sched_rr_ticks_consumed = 0;
+        self.apply_sched_prio();
+    }
+
     /// Block the context, and return true if it was runnable before being blocked
     pub fn block(&mut self, reason: &'static str) -> bool {
         if self.status.is_runnable() {
             self.status = Status::Blocked;
             self.status_reason = reason;
+            self.sched_rr_ticks_consumed = 0;
             true
         } else {
             false
@@ -232,6 +327,7 @@ impl Context {
     pub fn hard_block(&mut self, reason: HardBlockedReason) -> bool {
         if self.status.is_runnable() {
             self.status = Status::HardBlocked { reason };
+            self.sched_rr_ticks_consumed = 0;
 
             true
         } else {
@@ -261,6 +357,7 @@ impl Context {
         if self.status.is_soft_blocked() {
             self.status = Status::Runnable;
             self.status_reason = "";
+            self.sched_rr_ticks_consumed = 0;
 
             true
         } else {
@@ -479,6 +576,7 @@ impl Context {
             uid: self.euid,
             gid: self.egid,
             pid: self.pid,
+            groups: self.groups.clone(),
         }
     }
 }