Module Name:    src
Committed By:   para
Date:           Sat Jul 21 11:45:04 UTC 2012

Modified Files:
        src/sys/kern: subr_kmem.c

Log Message:
split allocation lookup table to decrease overall memory used
making allocator more flexible for allocations larger then 4kb
move the encoded "size" under DEBUG back to the begining of allocated chunk

no objections on tech-kern@


To generate a diff of this commit:
cvs rdiff -u -r1.45 -r1.46 src/sys/kern/subr_kmem.c

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.

Modified files:

Index: src/sys/kern/subr_kmem.c
diff -u src/sys/kern/subr_kmem.c:1.45 src/sys/kern/subr_kmem.c:1.46
--- src/sys/kern/subr_kmem.c:1.45	Sun Apr 15 19:07:40 2012
+++ src/sys/kern/subr_kmem.c	Sat Jul 21 11:45:04 2012
@@ -1,4 +1,4 @@
-/*	$NetBSD: subr_kmem.c,v 1.45 2012/04/15 19:07:40 martin Exp $	*/
+/*	$NetBSD: subr_kmem.c,v 1.46 2012/07/21 11:45:04 para Exp $	*/
 
 /*-
  * Copyright (c) 2009 The NetBSD Foundation, Inc.
@@ -61,7 +61,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: subr_kmem.c,v 1.45 2012/04/15 19:07:40 martin Exp $");
+__KERNEL_RCSID(0, "$NetBSD: subr_kmem.c,v 1.46 2012/07/21 11:45:04 para Exp $");
 
 #include <sys/param.h>
 #include <sys/callback.h>
@@ -77,10 +77,12 @@ __KERNEL_RCSID(0, "$NetBSD: subr_kmem.c,
 
 #include <lib/libkern/libkern.h>
 
-static const struct kmem_cache_info {
+struct kmem_cache_info {
 	size_t		kc_size;
 	const char *	kc_name;
-} kmem_cache_sizes[] = {
+};
+
+static const struct kmem_cache_info kmem_cache_sizes[] = {
 	{  8, "kmem-8" },
 	{ 16, "kmem-16" },
 	{ 24, "kmem-24" },
@@ -103,24 +105,39 @@ static const struct kmem_cache_info {
 	{ 512, "kmem-512" },
 	{ 768, "kmem-768" },
 	{ 1024, "kmem-1024" },
+	{ 0, NULL }
+};
+
+static const struct kmem_cache_info kmem_cache_big_sizes[] = {
 	{ 2048, "kmem-2048" },
 	{ 4096, "kmem-4096" },
+	{ 8192, "kmem-8192" },
+	{ 16384, "kmem-16384" },
 	{ 0, NULL }
 };
 
 /*
  * KMEM_ALIGN is the smallest guaranteed alignment and also the
- * smallest allocateable quantum.  Every cache size is a multiply
- * of CACHE_LINE_SIZE and gets CACHE_LINE_SIZE alignment.
+ * smallest allocateable quantum.
+ * Every cache size >= CACHE_LINE_SIZE gets CACHE_LINE_SIZE alignment.
  */
 #define	KMEM_ALIGN		8
 #define	KMEM_SHIFT		3
-#define	KMEM_MAXSIZE		4096
+#define	KMEM_MAXSIZE		1024
 #define	KMEM_CACHE_COUNT	(KMEM_MAXSIZE >> KMEM_SHIFT)
 
 static pool_cache_t kmem_cache[KMEM_CACHE_COUNT] __cacheline_aligned;
 static size_t kmem_cache_maxidx __read_mostly;
 
+#define	KMEM_BIG_ALIGN		2048
+#define	KMEM_BIG_SHIFT		11
+#define	KMEM_BIG_MAXSIZE	16384
+#define	KMEM_CACHE_BIG_COUNT	(KMEM_BIG_MAXSIZE >> KMEM_BIG_SHIFT)
+
+static pool_cache_t kmem_cache_big[KMEM_CACHE_BIG_COUNT] __cacheline_aligned;
+static size_t kmem_cache_big_maxidx __read_mostly;
+
+
 #if defined(DEBUG) && defined(_HARDKERNEL)
 #ifndef KMEM_GUARD_DEPTH
 #define KMEM_GUARD_DEPTH 0
@@ -163,6 +180,10 @@ static void kmem_size_check(void *, size
 CTASSERT(KM_SLEEP == PR_WAITOK);
 CTASSERT(KM_NOSLEEP == PR_NOWAIT);
 
+/*
+ * kmem_intr_alloc: allocate wired memory.
+ */
+
 void *
 kmem_intr_alloc(size_t size, km_flag_t kmflags)
 {
@@ -178,28 +199,41 @@ kmem_intr_alloc(size_t size, km_flag_t k
 		    (kmflags & KM_SLEEP) != 0);
 	}
 #endif
-	allocsz = kmem_roundup_size(size) + REDZONE_SIZE + SIZE_SIZE;
-	index = (allocsz - 1) >> KMEM_SHIFT;
+	size = kmem_roundup_size(size);
+	allocsz = size + REDZONE_SIZE + SIZE_SIZE;
 
-	if (index >= kmem_cache_maxidx) {
+	if ((index = ((allocsz -1) >> KMEM_SHIFT))
+	    < kmem_cache_maxidx) {
+		pc = kmem_cache[index];
+	} else if ((index = ((allocsz - 1) >> KMEM_BIG_SHIFT))
+            < kmem_cache_big_maxidx) {
+		pc = kmem_cache_big[index];
+	} else {	
 		int ret = uvm_km_kmem_alloc(kmem_va_arena,
 		    (vsize_t)round_page(size),
 		    ((kmflags & KM_SLEEP) ? VM_SLEEP : VM_NOSLEEP)
 		     | VM_INSTANTFIT, (vmem_addr_t *)&p);
-		return ret ? NULL : p;
+		if (ret) {
+			return NULL;
+		}
+		FREECHECK_OUT(&kmem_freecheck, p);
+		return p;
 	}
 
-	pc = kmem_cache[index];
 	p = pool_cache_get(pc, kmflags);
 
 	if (__predict_true(p != NULL)) {
-		kmem_poison_check(p, kmem_roundup_size(size));
+		kmem_poison_check(p, size);
 		FREECHECK_OUT(&kmem_freecheck, p);
-		kmem_size_set(p, allocsz);
+		kmem_size_set(p, size);
 	}
-	return p;
+	return p + SIZE_SIZE;
 }
 
+/*
+ * kmem_intr_zalloc: allocate zeroed wired memory.
+ */
+
 void *
 kmem_intr_zalloc(size_t size, km_flag_t kmflags)
 {
@@ -212,6 +246,10 @@ kmem_intr_zalloc(size_t size, km_flag_t 
 	return p;
 }
 
+/*
+ * kmem_intr_free: free wired memory allocated by kmem_alloc.
+ */
+
 void
 kmem_intr_free(void *p, size_t size)
 {
@@ -227,22 +265,30 @@ kmem_intr_free(void *p, size_t size)
 		return;
 	}
 #endif
-	allocsz = kmem_roundup_size(size) + REDZONE_SIZE + SIZE_SIZE;
-	index = (allocsz - 1) >> KMEM_SHIFT;
+	size = kmem_roundup_size(size);
+	allocsz = size + REDZONE_SIZE + SIZE_SIZE;
 
-	if (index >= kmem_cache_maxidx) {
+	if ((index = ((allocsz -1) >> KMEM_SHIFT))
+	    < kmem_cache_maxidx) {
+		pc = kmem_cache[index];
+	} else if ((index = ((allocsz - 1) >> KMEM_BIG_SHIFT))
+            < kmem_cache_big_maxidx) {
+		pc = kmem_cache_big[index];
+	} else {
+		FREECHECK_IN(&kmem_freecheck, p);
 		uvm_km_kmem_free(kmem_va_arena, (vaddr_t)p,
 		    round_page(size));
 		return;
 	}
 
-	kmem_size_check(p, allocsz);
+	p = (uint8_t *)p - SIZE_SIZE;
+	kmem_size_check(p, size);
 	FREECHECK_IN(&kmem_freecheck, p);
-	LOCKDEBUG_MEM_CHECK(p, allocsz - (REDZONE_SIZE + SIZE_SIZE));
-	kmem_poison_check((uint8_t *)p + size, allocsz - size - SIZE_SIZE);
+	LOCKDEBUG_MEM_CHECK(p, size);
+	kmem_poison_check((uint8_t *)p + SIZE_SIZE + size,
+      	    allocsz - (SIZE_SIZE + size));
 	kmem_poison_fill(p, allocsz);
 
-	pc = kmem_cache[index];
 	pool_cache_put(pc, p);
 }
 
@@ -290,17 +336,19 @@ kmem_free(void *p, size_t size)
 	kmem_intr_free(p, size);
 }
 
-static void
+static size_t
 kmem_create_caches(const struct kmem_cache_info *array,
-    pool_cache_t alloc_table[], size_t maxsize)
+    pool_cache_t alloc_table[], size_t maxsize, int shift, int ipl)
 {
-	size_t table_unit = (1 << KMEM_SHIFT);
+	size_t maxidx = 0;
+	size_t table_unit = (1 << shift);
 	size_t size = table_unit;
 	int i;
 
 	for (i = 0; array[i].kc_size != 0 ; i++) {
 		const char *name = array[i].kc_name;
 		size_t cache_size = array[i].kc_size;
+		struct pool_allocator *pa;
 		int flags = PR_NOALIGN;
 		pool_cache_t pc;
 		size_t align;
@@ -316,27 +364,33 @@ kmem_create_caches(const struct kmem_cac
 			flags |= PR_NOTOUCH;
 
 		/* check if we reached the requested size */
-		if (cache_size > maxsize) {
+		if (cache_size > maxsize || cache_size > PAGE_SIZE) {
 			break;
 		}
-		if ((cache_size >> KMEM_SHIFT) > kmem_cache_maxidx) {
-			kmem_cache_maxidx = cache_size >> KMEM_SHIFT;
+		if ((cache_size >> shift) > maxidx) {
+			maxidx = cache_size >> shift;
+		}
+
+		if ((cache_size >> shift) > maxidx) {
+			maxidx = cache_size >> shift;
 		}
 
+		pa = &pool_allocator_kmem;
 #if defined(KMEM_POISON)
 		pc = pool_cache_init(cache_size, align, 0, flags,
-		    name, &pool_allocator_kmem, IPL_VM, kmem_poison_ctor,
+		    name, pa, ipl,kmem_poison_ctor,
 		    NULL, (void *)cache_size);
 #else /* defined(KMEM_POISON) */
 		pc = pool_cache_init(cache_size, align, 0, flags,
-		    name, &pool_allocator_kmem, IPL_VM, NULL, NULL, NULL);
+		    name, pa, ipl, NULL, NULL, NULL);
 #endif /* defined(KMEM_POISON) */
 
 		while (size <= cache_size) {
-			alloc_table[(size - 1) >> KMEM_SHIFT] = pc;
+			alloc_table[(size - 1) >> shift] = pc;
 			size += table_unit;
 		}
 	}
+	return maxidx;
 }
 
 void
@@ -347,7 +401,10 @@ kmem_init(void)
 	uvm_kmguard_init(&kmem_guard, &kmem_guard_depth, &kmem_guard_size,
 	    kmem_va_arena);
 #endif
-	kmem_create_caches(kmem_cache_sizes, kmem_cache, KMEM_MAXSIZE);
+	kmem_cache_maxidx = kmem_create_caches(kmem_cache_sizes,
+	    kmem_cache, KMEM_MAXSIZE, KMEM_SHIFT, IPL_VM);
+       	kmem_cache_big_maxidx = kmem_create_caches(kmem_cache_big_sizes,
+	    kmem_cache_big, PAGE_SIZE, KMEM_BIG_SHIFT, IPL_VM);
 }
 
 size_t
@@ -424,23 +481,19 @@ kmem_poison_check(void *p, size_t sz)
 static void
 kmem_size_set(void *p, size_t sz)
 {
-	void *szp;
-
-	szp = (uint8_t *)p + sz - SIZE_SIZE;
-	memcpy(szp, &sz, sizeof(sz));
+	
+	memcpy(p, &sz, sizeof(sz));
 }
 
 static void
 kmem_size_check(void *p, size_t sz)
 {
-	uint8_t *szp;
 	size_t psz;
 
-	szp = (uint8_t *)p + sz - SIZE_SIZE;
-	memcpy(&psz, szp, sizeof(psz));
+	memcpy(&psz, p, sizeof(psz));
 	if (psz != sz) {
 		panic("kmem_free(%p, %zu) != allocated size %zu",
-		    (const uint8_t *)p + SIZE_SIZE, sz - SIZE_SIZE, psz);
+		    (const uint8_t *)p + SIZE_SIZE, sz, psz);
 	}
 }
 #endif	/* defined(KMEM_SIZE) */

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