Second Extended Filesystem (ext2) and other improvements (#33)

[lunaix-os.git] / lunaix-os / kernel / process / preemption.c

diff --git a/lunaix-os/kernel/process/preemption.c b/lunaix-os/kernel/process/preemption.c
new file mode 100644 (file)
index 0000000..e89a593
--- /dev/null
+++ b/lunaix-os/kernel/process/preemption.c
@@ -0,0 +1,82 @@
+#include <lunaix/kpreempt.h>
+#include <lunaix/process.h>
+#include <lunaix/switch.h>
+#include <lunaix/syslog.h>
+#include <lunaix/trace.h>
+
+LOG_MODULE("preempt");
+
+#ifdef CONFIG_CHECK_STALL
+bool
+preempt_check_stalled(struct thread* th)
+{
+    // we can't access the hart state here
+    //  as th might be in other address space
+
+    if (thread_flags_test(th, TH_STALLED))
+    {
+        // alrady stalled, no need to concern
+        return false;
+    }
+
+    struct thread_stats* stats;
+    stats   = &th->stats;
+
+    if (!stats->kpreempt_count) {
+        return false;
+    }
+
+    if (stats->at_user) {
+        return false;
+    }
+
+#if defined(CONFIG_STALL_MAX_PREEMPTS) && CONFIG_STALL_MAX_PREEMPTS
+    if (stats->kpreempt_count > CONFIG_STALL_MAX_PREEMPTS) {
+        return true;
+    }
+#endif
+
+    ticks_t total_elapsed;
+    total_elapsed = thread_stats_kernel_elapse(th);
+
+    return total_elapsed > ticks_seconds(CONFIG_STALL_TIMEOUT);
+}
+
+#else 
+bool
+preempt_check_stalled(struct thread* th)
+{
+    return false;
+}
+
+#endif
+
+void
+preempt_handle_stalled(struct signpost_result* result)
+{
+    if (!thread_flags_test(current_thread, TH_STALLED))
+    {
+        continue_switch(result);
+        return;
+    }
+
+    kprintf("+++++ ");
+    kprintf(" stalling detected (pid: %d, tid: %d)", 
+                __current->pid, current_thread->tid);
+    kprintf(" (preempted: %d, elapsed: %dms)", 
+                current_thread->stats.kpreempt_count, 
+                thread_stats_kernel_elapse(current_thread));
+    kprintf("   are you keeping Luna too busy?");
+    kprintf("+++++ ");
+
+    kprintf("last known state:");
+    trace_dump_state(current_thread->hstate);
+
+    kprintf("trace from the point of stalling:");
+    trace_printstack_isr(current_thread->hstate);
+
+    kprintf("thread is blocked");
+
+    block_current_thread();
+    giveup_switch(result);
+}
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