From 022fcc44c5059e7debf3b2442b554ee0bc36212a Mon Sep 17 00:00:00 2001
From: Christoph Lameter <clameter@sgi.com>
Date: Sat, 28 Jul 2007 12:35:30 -0700
Subject: [PATCH] Simple Performance Counters: SLUB instrumentation

With this patch SLUB will perform tests on bootup and display results.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
---
 mm/slub.c |   97 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++----
 1 file changed, 92 insertions(+), 5 deletions(-)

Index: linux-2.6/mm/slub.c
===================================================================
--- linux-2.6.orig/mm/slub.c	2007-07-28 22:42:49.000000000 -0700
+++ linux-2.6/mm/slub.c	2007-07-28 22:44:21.000000000 -0700
@@ -20,6 +20,7 @@
 #include <linux/mempolicy.h>
 #include <linux/ctype.h>
 #include <linux/kallsyms.h>
+#include <linux/perf.h>
 
 /*
  * Lock order:
@@ -152,6 +153,7 @@ static inline void ClearSlabDebug(struct
 
 /* Enable to test recovery from slab corruption on boot */
 #undef SLUB_RESILIENCY_TEST
+#undef SLUB_PERFORMANCE_TEST
 
 #if PAGE_SHIFT <= 12
 
@@ -2869,9 +2871,97 @@ static long validate_slab_cache(struct k
 	return count;
 }
 
-#ifdef SLUB_RESILIENCY_TEST
 static void resiliency_test(void)
 {
+#ifdef SLUB_PERFORMANCE_TEST
+#define TEST_COUNT 10000
+	int size, i;
+	struct pc x;
+	void **v = kmalloc(TEST_COUNT * sizeof(void *), GFP_KERNEL);
+
+	printk(KERN_INFO "SLUB Performance testing\n");
+	printk(KERN_INFO "========================\n");
+	printk(KERN_INFO "1. Kmalloc: Repeatedly allocate then free test\n");
+	for (size = 8; size <= PAGE_SIZE << 2; size <<= 1) {
+		pc_start(&x);
+		for(i = 0; i < TEST_COUNT; i++) {
+			v[i] = kmalloc(size, GFP_KERNEL);
+		}
+		printk(KERN_INFO "%i times kmalloc(%d) = ", i, size);
+		pc_stop_printk(&x);
+		pc_start(&x);
+		for(i = 0; i < TEST_COUNT; i++)
+			kfree(v[i]);
+		printk(" kfree() = ");
+		pc_stop_printk(&x);
+		printk("\n");
+	}
+
+	printk(KERN_INFO "2. Kmalloc: alloc/free test\n");
+	for (size = 8; size <= PAGE_SIZE << 2; size <<= 1) {
+		pc_start(&x);
+		for(i = 0; i < TEST_COUNT; i++)
+			kfree(kmalloc(size, GFP_KERNEL));
+		printk(KERN_INFO "%i times kmalloc(%d)/kfree = ", i, size);
+		pc_stop_printk(&x);
+		printk("\n");
+	}
+	printk(KERN_INFO "3. kmem_cache_alloc: Repeatedly allocate then free test\n");
+	for (size = 3; size <= PAGE_SHIFT; size ++) {
+		pc_start(&x);
+		for(i = 0; i < TEST_COUNT; i++) {
+			v[i] = kmem_cache_alloc(kmalloc_caches + size, GFP_KERNEL);
+		}
+		printk(KERN_INFO "%d times kmem_cache_alloc(%d) = ", i, 1 << size);
+		pc_stop_printk(&x);
+		pc_start(&x);
+		for(i = 0; i < TEST_COUNT; i++)
+			kmem_cache_free(kmalloc_caches + size, v[i]);
+		printk(" kmem_cache_free() = ");
+		pc_stop_printk(&x);
+		printk("\n");
+	}
+
+	printk(KERN_INFO "4. kmem_cache_alloc: alloc/free test\n");
+	for (size = 3; size <= PAGE_SHIFT; size++) {
+		pc_start(&x);
+		for(i = 0; i < TEST_COUNT; i++)
+			kmem_cache_free(kmalloc_caches + size,
+				kmem_cache_alloc(kmalloc_caches + size,
+							GFP_KERNEL));
+		printk(KERN_INFO "%d times kmem_cache_alloc(%d)/kmem_cache_free = ", i, 1 << size);
+		pc_stop_printk(&x);
+		printk("\n");
+	}
+	printk(KERN_INFO "5. kmem_cache_zalloc: Repeatedly allocate then free test\n");
+	for (size = 3; size <= PAGE_SHIFT; size ++) {
+		pc_start(&x);
+		for(i = 0; i < TEST_COUNT; i++) {
+			v[i] = kmem_cache_zalloc(kmalloc_caches + size, GFP_KERNEL);
+		}
+		printk(KERN_INFO "%d times kmem_cache_zalloc(%d) = ", i, 1 << size);
+		pc_stop_printk(&x);
+		pc_start(&x);
+		for(i = 0; i < TEST_COUNT; i++)
+			kmem_cache_free(kmalloc_caches + size, v[i]);
+		printk(" kmem_cache_free() = ");
+		pc_stop_printk(&x);
+		printk("\n");
+	}
+
+	printk(KERN_INFO "6. kmem_cache_zalloc: alloc/free test\n");
+	for (size = 3; size <= PAGE_SHIFT; size++) {
+		pc_start(&x);
+		for(i = 0; i < TEST_COUNT; i++)
+			kmem_cache_free(kmalloc_caches + size,
+				kmem_cache_zalloc(kmalloc_caches + size,
+							GFP_KERNEL));
+		printk(KERN_INFO "%d times kmem_cache_zalloc(%d)/kmem_cache_free = ", i, 1 << size);
+		pc_stop_printk(&x);
+		printk("\n");
+	}
+#endif
+#ifdef SLUB_RESILIENCY_TEST
 	u8 *p;
 
 	printk(KERN_ERR "SLUB resiliency testing\n");
@@ -2919,11 +3009,8 @@ static void resiliency_test(void)
 	p[512] = 0xab;
 	printk(KERN_ERR "\n3. kmalloc-512: Clobber redzone 0xab->0x%p\n\n", p);
 	validate_slab_cache(kmalloc_caches + 9);
-}
-#else
-static void resiliency_test(void) {};
 #endif
-
+}
 /*
  * Generate lists of code addresses where slabcache objects are allocated
  * and freed.