ke: move priority out of thread

src/ex/work.zig

@@ -50,7 +50,7 @@ pub const WorkItem = struct {
         /// High priority work.
         High,
 
-        pub fn to_sched_prio(prio: Priority) ke.Thread.Priority {
+        pub fn to_sched_prio(prio: Priority) ke.Priority {
             return switch (prio) {
                 .Low => .LowBatch,
                 .Normal => .HighBatch,
@@ -128,7 +128,7 @@ const Pool = struct {
                 @ptrFromInt(ctx.value),
             );
 
-            td.kern.nice = -ke.Thread.Priority.nice_max;
+            td.kern.nice = -ke.Priority.nice_max;
 
             if (cpu != null) {
                 td.kern.last_cpu = cpu;

src/kern/root.zig

@@ -21,6 +21,7 @@ pub const Queue = p.queue.Queue;
 pub const Mutex = p.mutex.Mutex;
 pub const ShootdownState = p.shootdown.ShootdownState;
 pub const Tunable = p.tunable.Tunable;
+pub const Priority = p.thread.Priority;
 
 // === Exported Interfaces ===
 pub const panic = p.panic.panic;

src/kern/sched.zig

@@ -104,7 +104,7 @@ const pl = r.pl;
 const runqueues_n = 64;
 const interactivity_threshold = 30;
 const scaling_factor = 50;
-const preempt_threshold = @intFromEnum(ke.Thread.Priority.LowRealtime);
+const preempt_threshold = @intFromEnum(ke.Priority.LowRealtime);
 const balance_interval = @as(u64, config.sched_balance_interval);
 const steal_threshold = 1;
 const pct_window_target = 10 * std.time.us_per_s;
@@ -536,7 +536,7 @@ fn recompute_priority(td: *ke.Thread) void {
         // Choose a priority based on score, the lower the score,
         // the higher the priority it will be.
         // This is a simple formula I came up with that is probably good enough.
-        @intCast(@intFromEnum(ke.Thread.Priority.LowInteractive) +
+        @intCast(@intFromEnum(ke.Priority.LowInteractive) +
             ((interactivity_threshold - score) / 2))
     else blk: {
         // Thread is not interactive, compute priority from recent CPU usage.
@@ -544,7 +544,7 @@ fn recompute_priority(td: *ke.Thread) void {
         // thread has spent running, we want to punish threads that got to run
         // a lot and reward threads that got starved.
         const len = @max(1, td.acct.stamp - td.acct.pct_window_start);
-        const cpu_range = ke.Thread.Priority.cpu_range;
+        const cpu_range = ke.Priority.cpu_range;
 
         const cpu_pri_off: u8 = @intCast(@min(
             cpu_range - 1,
@@ -553,16 +553,16 @@ fn recompute_priority(td: *ke.Thread) void {
 
         // nice offset: negative nice increases priority value,
         // positive decreases it.
-        const nice_off: i16 = @as(i16, td.nice) + ke.Thread.Priority.nice_max;
+        const nice_off: i16 = @as(i16, td.nice) + ke.Priority.nice_max;
 
-        const raw: i16 = @as(i16, @intFromEnum(ke.Thread.Priority.HighBatch)) -
+        const raw: i16 = @as(i16, @intFromEnum(ke.Priority.HighBatch)) -
             @as(i16, cpu_pri_off) -
             nice_off;
 
         break :blk @intCast(std.math.clamp(
             raw,
-            @intFromEnum(ke.Thread.Priority.LowBatch),
+            @intFromEnum(ke.Priority.LowBatch),
-            @intFromEnum(ke.Thread.Priority.HighBatch),
+            @intFromEnum(ke.Priority.HighBatch),
         ));
     };
 
@@ -593,7 +593,7 @@ fn pick_realtime_thread(cpu: *PerCpu, minimum_prio: u8, migrate: bool) ?*ke.Thre
     if (runq.status == 0) return null;
 
     // Search higher priority queues first.
-    var i: usize = to_sched_prio(ke.Thread.Priority.max);
+    var i: usize = to_sched_prio(ke.Priority.max);
 
     qloop: while (i >= minprio and i > 0) : (i -= 1) {
         const bit = (@as(u64, 1) << @intCast(i));
@@ -754,7 +754,7 @@ fn insert_in_queue(cpu: *PerCpu, td: *ke.Thread, preempted: bool) void {
         // Insert in calendar queue.
         // The insertion index is determined by insidx and the the priority of the thread,
         // higher priority threads will be put closer to insidx, which ensures that they are ran more frequently.
-        var idx = (cpu.insidx + (@intFromEnum(ke.Thread.Priority.HighBatch) -
+        var idx = (cpu.insidx + (@intFromEnum(ke.Priority.HighBatch) -
             td.priority)) % runqueues_n;
 
         if (preempted) {
@@ -861,7 +861,7 @@ fn select_thread(cur: ?*ke.Thread, cpu: *PerCpu, migrate: bool) ?*ke.Thread {
 // Return whether or not a thread with given priority and interactivity should
 //  get preempted by `td`.
 fn should_prio_preempt(td: *ke.Thread, other_prio: u8, remote: bool) bool {
-    const class = ke.Thread.Priority.class_from_prio(other_prio);
+    const class = ke.Priority.class_from_prio(other_prio);
 
     if (td.priority <= other_prio) {
         // If our priority is lower or equal, ignore.
@@ -874,7 +874,7 @@ fn should_prio_preempt(td: *ke.Thread, other_prio: u8, remote: bool) bool {
     }
 
     if (class == .Timeshare and td.is_interactive() and
-        other_prio < @intFromEnum(ke.Thread.Priority.LowInteractive) and remote)
+        other_prio < @intFromEnum(ke.Priority.LowInteractive) and remote)
     {
         // Interactive threads always preempt batch non-interactive ones
         // on remote CPUs.

src/kern/thread.zig

@@ -5,62 +5,62 @@ const rtl = @import("rtl");
 const ke = r.ke;
 const ki = ke.private;
 
-/// Structure representing a kernel thread.
+pub const Priority = enum(u8) {
-pub const Thread = struct {
+    const Self = @This();
-    pub const Priority = enum(u8) {
-        const Self = @This();
 
-        /// Reserved for the idle thread.
+    /// Reserved for the idle thread.
-        IdleThread = 0,
+    IdleThread = 0,
-        /// Background kernel work.
+    /// Background kernel work.
-        Idle = 1,
+    Idle = 1,
-        /// Low priority CPU-bound work
+    /// Low priority CPU-bound work
-        LowBatch = 2,
+    LowBatch = 2,
-        /// High priority CPU-bound work
+    /// High priority CPU-bound work
-        HighBatch = 137,
+    HighBatch = 137,
-        /// Low priority interactive work.
+    /// Low priority interactive work.
-        LowInteractive = 138,
+    LowInteractive = 138,
-        /// High priority interactive work.
+    /// High priority interactive work.
-        HighInteractive = 223,
+    HighInteractive = 223,
-        /// The default thread priority.
+    /// The default thread priority.
-        Default = 117,
+    Default = 117,
-        /// Low priority real-time work.
+    /// Low priority real-time work.
-        LowRealtime = 224,
+    LowRealtime = 224,
-        /// Mid priority real-time work.
+    /// Mid priority real-time work.
-        MidRealtime = 239,
+    MidRealtime = 239,
-        /// High priority real-time work.
+    /// High priority real-time work.
-        HighRealtime = 255,
+    HighRealtime = 255,
-        _,
+    _,
 
-        pub const Class = enum(u8) {
+    pub const Class = enum(u8) {
-            Realtime,
+        Realtime,
-            Timeshare,
+        Timeshare,
-            Idle,
+        Idle,
-        };
-
-        pub const max = 255;
-        pub const nice_max = 20;
-
-        // The low and top 20 priorities from the batch range are reserved
-        // for nice.
-        pub const cpu_range = @intFromEnum(Self.HighBatch) - (nice_max * 2) - 1;
-
-        pub fn class_from_prio(prio: u8) Class {
-            if (prio >= @intFromEnum(Self.LowRealtime) and
-                prio <= @intFromEnum(Self.HighRealtime))
-                return .Realtime;
-
-            if (prio >= @intFromEnum(Self.LowBatch) and
-                prio < @intFromEnum(Self.LowRealtime))
-                return .Timeshare;
-
-            if (prio <= @intFromEnum(Self.Idle))
-                return .Idle;
-
-            unreachable;
-        }
     };
 
+    pub const max = 255;
+    pub const nice_max = 20;
+
+    // The low and top 20 priorities from the batch range are reserved
+    // for nice.
+    pub const cpu_range = @intFromEnum(Self.HighBatch) - (nice_max * 2) - 1;
+
+    pub fn class_from_prio(prio: u8) Class {
+        if (prio >= @intFromEnum(Self.LowRealtime) and
+            prio <= @intFromEnum(Self.HighRealtime))
+            return .Realtime;
+
+        if (prio >= @intFromEnum(Self.LowBatch) and
+            prio < @intFromEnum(Self.LowRealtime))
+            return .Timeshare;
+
+        if (prio <= @intFromEnum(Self.Idle))
+            return .Idle;
+
+        unreachable;
+    }
+};
+
+/// Structure representing a kernel thread.
+pub const Thread = struct {
     /// Thread state.
     pub const State = enum(u8) {
         /// The thread is ready to run.

src/proc/thread.zig

@@ -56,7 +56,7 @@ pub fn init() void {
 /// - `entry`: entry point.
 /// - `arg`: argument passed to `entry`.
 pub fn create_kernel(
-    prio: ke.Thread.Priority,
+    prio: ke.Priority,
     entry: *const fn (arg: ?*anyopaque) void,
     arg: ?*anyopaque,
 ) !*Thread {