From eacd93b32d29d351be2f66b6533d148180ee2626 Mon Sep 17 00:00:00 2001
From: Gleb Koval <gleb@koval.net>
Date: Wed, 16 Oct 2024 22:56:47 +0100
Subject: [PATCH] Optimise load_avg and recent_cpu updates - only run when BSD
 scheduler is enabled

---
 src/threads/thread.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/threads/thread.c b/src/threads/thread.c
index e4d392b..230789e 100644
--- a/src/threads/thread.c
+++ b/src/threads/thread.c
@@ -155,7 +155,7 @@ thread_tick (void)
 
   /* Update system load_avg and all threads recent_cpu every second. */
   int64_t ticks = timer_ticks ();
-  if (ticks % TIMER_FREQ == 0)
+  if (thread_mlfqs && (ticks % TIMER_FREQ == 0))
     {
       fp32_t old_coeff = fp_mul (fp_div_int (int_to_fp (59), 60), load_avg);
       fp32_t new_coeff = fp_div_int (int_to_fp (threads_ready ()), 60);
@@ -165,7 +165,7 @@ thread_tick (void)
     }
 
   /* Update current thread's recent_cpu. */
-  if (t != idle_thread)
+  if (thread_mlfqs && (t != idle_thread))
     {
       t->recent_cpu = fp_add_int (t->recent_cpu, 1);
       if (ticks % 4 == 0) // recent_cpu was updated, update priority.