Initial import

1 files changed, 93 insertions, 0 deletions

diff --git a/include/linux/quicklist.h b/include/linux/quicklist.h
new file mode 100644
index 000000000..bd466439c
--- /dev/null
+++ b/include/linux/quicklist.h
@@ -0,0 +1,93 @@
+#ifndef LINUX_QUICKLIST_H
+#define LINUX_QUICKLIST_H
+/*
+ * Fast allocations and disposal of pages. Pages must be in the condition
+ * as needed after allocation when they are freed. Per cpu lists of pages
+ * are kept that only contain node local pages.
+ *
+ * (C) 2007, SGI. Christoph Lameter <clameter@sgi.com>
+ */
+#include <linux/kernel.h>
+#include <linux/gfp.h>
+#include <linux/percpu.h>
+
+#ifdef CONFIG_QUICKLIST
+
+struct quicklist {
+	void *page;
+	int nr_pages;
+};
+
+DECLARE_PER_CPU(struct quicklist, quicklist)[CONFIG_NR_QUICK];
+
+/*
+ * The two key functions quicklist_alloc and quicklist_free are inline so
+ * that they may be custom compiled for the platform.
+ * Specifying a NULL ctor can remove constructor support. Specifying
+ * a constant quicklist allows the determination of the exact address
+ * in the per cpu area.
+ *
+ * The fast patch in quicklist_alloc touched only a per cpu cacheline and
+ * the first cacheline of the page itself. There is minmal overhead involved.
+ */
+static inline void *quicklist_alloc(int nr, gfp_t flags, void (*ctor)(void *))
+{
+	struct quicklist *q;
+	void **p = NULL;
+
+	q =&get_cpu_var(quicklist)[nr];
+	p = q->page;
+	if (likely(p)) {
+		q->page = p[0];
+		p[0] = NULL;
+		q->nr_pages--;
+	}
+	put_cpu_var(quicklist);
+	if (likely(p))
+		return p;
+
+	p = (void *)__get_free_page(flags | __GFP_ZERO);
+	if (ctor && p)
+		ctor(p);
+	return p;
+}
+
+static inline void __quicklist_free(int nr, void (*dtor)(void *), void *p,
+	struct page *page)
+{
+	struct quicklist *q;
+
+	q = &get_cpu_var(quicklist)[nr];
+	*(void **)p = q->page;
+	q->page = p;
+	q->nr_pages++;
+	put_cpu_var(quicklist);
+}
+
+static inline void quicklist_free(int nr, void (*dtor)(void *), void *pp)
+{
+	__quicklist_free(nr, dtor, pp, virt_to_page(pp));
+}
+
+static inline void quicklist_free_page(int nr, void (*dtor)(void *),
+							struct page *page)
+{
+	__quicklist_free(nr, dtor, page_address(page), page);
+}
+
+void quicklist_trim(int nr, void (*dtor)(void *),
+	unsigned long min_pages, unsigned long max_free);
+
+unsigned long quicklist_total_size(void);
+
+#else
+
+static inline unsigned long quicklist_total_size(void)
+{
+	return 0;
+}
+
+#endif
+
+#endif /* LINUX_QUICKLIST_H */
+