grub2/0002-mm-Defer-the-disk-cache-invalidation.patch

From 4284d40799aaf5aab11c690f232ce0a191dcfbdb Mon Sep 17 00:00:00 2001
From: Gary Lin <glin@suse.com>
Date: Fri, 16 Sep 2022 10:59:55 +0800
Subject: [PATCH 2/2] mm: Defer the disk cache invalidation

When the heap memory is used up, the memory management code invalidates
the disk caches first and then requests the additional memory regioins.
Although this could minimize the memory usage, it hurts the loading time
since the disk caches may always miss.

This patch defers the disk cache invalidation to avoid the possible
delays.

Signen-off-by: Gary Lin <glin@suse.com>
---
 grub-core/kern/mm.c | 22 +++++++---------------
 1 file changed, 7 insertions(+), 15 deletions(-)

diff --git a/grub-core/kern/mm.c b/grub-core/kern/mm.c
index 0bd9f75..5280e8c 100644
--- a/grub-core/kern/mm.c
+++ b/grub-core/kern/mm.c
@@ -355,20 +355,6 @@ grub_memalign (grub_size_t align, grub_size_t size)
   switch (count)
     {
     case 0:
-      /* Invalidate disk caches.  */
-      grub_disk_cache_invalidate_all ();
-      count++;
-      goto again;
-
-#if 0
-    case 1:
-      /* Unload unneeded modules.  */
-      grub_dl_unload_unneeded ();
-      count++;
-      goto again;
-#endif
-
-    case 1:
       /* Request additional pages, contiguous */
       count++;
 
@@ -378,7 +364,7 @@ grub_memalign (grub_size_t align, grub_size_t size)
 
       /* fallthrough  */
 
-    case 2:
+    case 1:
       /* Request additional pages, anything at all */
       count++;
 
@@ -394,6 +380,12 @@ grub_memalign (grub_size_t align, grub_size_t size)
 
       /* fallthrough */
 
+    case 2:
+      /* Invalidate disk caches.  */
+      grub_disk_cache_invalidate_all ();
+      count++;
+      goto again;
+
     default:
       break;
     }
-- 
2.35.3