From 069b4fb65ec13741c40356c16c312a50771fb589 Mon Sep 17 00:00:00 2001
From: Justus Winter <4winter@informatik.uni-hamburg.de>
Date: Sun, 5 Jan 2014 19:51:11 +0100
Subject: kern: explain the significance of the chosen length

* kern/slab.h (KMEM_CACHE_NAME_SIZE): Explain the significance of the
chosen length.
---
 kern/slab.h | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

(limited to 'kern/slab.h')

diff --git a/kern/slab.h b/kern/slab.h
index a4219c4..fd65893 100644
--- a/kern/slab.h
+++ b/kern/slab.h
@@ -147,7 +147,9 @@ typedef vm_offset_t (*kmem_slab_alloc_fn_t)(vm_size_t);
 typedef void (*kmem_slab_free_fn_t)(vm_offset_t, vm_size_t);
 
 /*
- * Cache name buffer size.
+ * Cache name buffer size.  The size is chosen so that struct
+ * kmem_cache fits into two cache lines.  The size of a cache line on
+ * a typical CPU is 64 bytes.
  */
 #define KMEM_CACHE_NAME_SIZE 24
 
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