linux-kernel - [PATCH] SLOB allocator imcompatible SLAB

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Date:	Fri, 22 Jun 2007 17:08:07 +0900
From:	Yoshinori Sato <ysato@...rs.sourceforge.jp>
To:	Matt Mackall <mpm@...enic.com>
Cc:	lkml <linux-kernel@...r.kernel.org>
Subject: [PATCH] SLOB allocator imcompatible SLAB

Because the page which SLOB allocator got does not have PG_slab,
I put back the result that kobjsize made a mistake in.

allocateしたページにPG_slabを付ける必要があるのでは無いでしょうか。
I need to add PG_slab to the allocate page, and will not there be it?

Signed-off-by: Yoshinori Sato <ysato@...rs.sourceforge.jp>

diff --git a/mm/slob.c b/mm/slob.c
index 71976c5..d10bcda 100644
--- a/mm/slob.c
+++ b/mm/slob.c
@@ -73,6 +73,21 @@ static DEFINE_SPINLOCK(block_lock);
 static void slob_free(void *b, int size);
 static void slob_timer_cbk(void);
 
+static inline void set_slabflags(const void *ptr, int order)
+{
+	int i;
+	struct page *page = virt_to_page(ptr);
+	for (i = 0; i < (1 << order); i++)
+		__SetPageSlab(page++);
+}
+
+static inline void clear_slabflags(const void *ptr, int order)
+{
+	int i;
+	struct page *page = virt_to_page(ptr);
+	for (i = 0; i < (1 << order); i++)
+		__ClearPageSlab(page++);
+}
 
 static void *slob_alloc(size_t size, gfp_t gfp, int align)
 {
@@ -180,6 +195,7 @@ void *__kmalloc(size_t size, gfp_t gfp)
 	bb->pages = (void *)__get_free_pages(gfp, bb->order);
 
 	if (bb->pages) {
+		set_slabflags(bb->pages, bb->order);
 		spin_lock_irqsave(&block_lock, flags);
 		bb->next = bigblocks;
 		bigblocks = bb;
@@ -240,6 +256,7 @@ void kfree(const void *block)
 			if (bb->pages == block) {
 				*last = bb->next;
 				spin_unlock_irqrestore(&block_lock, flags);
+				clear_slabflags(block, bb->order);
 				free_pages((unsigned long)block, bb->order);
 				slob_free(bb, sizeof(bigblock_t));
 				return;
@@ -323,9 +340,11 @@ void *kmem_cache_alloc(struct kmem_cache *c, gfp_t flags)
 
 	if (c->size < PAGE_SIZE)
 		b = slob_alloc(c->size, flags, c->align);
-	else
+	else {
 		b = (void *)__get_free_pages(flags, get_order(c->size));
-
+		if (b)
+			set_slabflags(b, get_order(c->size));
+	}
 	if (c->ctor)
 		c->ctor(b, c, 0);
 
@@ -347,8 +366,10 @@ static void __kmem_cache_free(void *b, int size)
 {
 	if (size < PAGE_SIZE)
 		slob_free(b, size);
-	else
+	else {
+		clear_slabflags(b, get_order(size));
 		free_pages((unsigned long)b, get_order(size));
+	}
 }
 
 static void kmem_rcu_free(struct rcu_head *head)

-- 
Yoshinori Sato
<ysato@...rs.sourceforge.jp>
-
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