---

yaml
---
r: 54214
b: refs/heads/master
c: 6225e93
h: refs/heads/master
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: c09d87517298fd01543739ba26987645deb4e6a9
+refs/heads/master: 6225e93735acaa09865bce746958f1046c2e0bc3

trunk/include/linux/quicklist.h

@@ -0,0 +1,94 @@
+#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;
+	int nid = page_to_nid(page);
+
+	if (unlikely(nid != numa_node_id())) {
+		if (dtor)
+			dtor(p);
+		__free_page(page);
+		return;
+	}
+
+	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);
+
+#endif
+
+#endif /* LINUX_QUICKLIST_H */
+

trunk/mm/Kconfig

@@ -163,3 +163,8 @@ config ZONE_DMA_FLAG
 	default "0" if !ZONE_DMA
 	default "1"
 
+config NR_QUICK
+	int
+	depends on QUICKLIST
+	default "1"
+

trunk/mm/Makefile

@@ -30,3 +30,5 @@ obj-$(CONFIG_MEMORY_HOTPLUG) += memory_hotplug.o
 obj-$(CONFIG_FS_XIP) += filemap_xip.o
 obj-$(CONFIG_MIGRATION) += migrate.o
 obj-$(CONFIG_SMP) += allocpercpu.o
+obj-$(CONFIG_QUICKLIST) += quicklist.o
+

trunk/mm/quicklist.c

@@ -0,0 +1,88 @@
+/*
+ * Quicklist support.
+ *
+ * Quicklists are light weight lists of pages that have a defined state
+ * on alloc and free. Pages must be in the quicklist specific defined state
+ * (zero by default) when the page is freed. It seems that the initial idea
+ * for such lists first came from Dave Miller and then various other people
+ * improved on it.
+ *
+ * Copyright (C) 2007 SGI,
+ * 	Christoph Lameter <clameter@sgi.com>
+ * 		Generalized, added support for multiple lists and
+ * 		constructors / destructors.
+ */
+#include <linux/kernel.h>
+
+#include <linux/mm.h>
+#include <linux/mmzone.h>
+#include <linux/module.h>
+#include <linux/quicklist.h>
+
+DEFINE_PER_CPU(struct quicklist, quicklist)[CONFIG_NR_QUICK];
+
+#define FRACTION_OF_NODE_MEM	16
+
+static unsigned long max_pages(unsigned long min_pages)
+{
+	unsigned long node_free_pages, max;
+
+	node_free_pages = node_page_state(numa_node_id(),
+			NR_FREE_PAGES);
+	max = node_free_pages / FRACTION_OF_NODE_MEM;
+	return max(max, min_pages);
+}
+
+static long min_pages_to_free(struct quicklist *q,
+	unsigned long min_pages, long max_free)
+{
+	long pages_to_free;
+
+	pages_to_free = q->nr_pages - max_pages(min_pages);
+
+	return min(pages_to_free, max_free);
+}
+
+/*
+ * Trim down the number of pages in the quicklist
+ */
+void quicklist_trim(int nr, void (*dtor)(void *),
+	unsigned long min_pages, unsigned long max_free)
+{
+	long pages_to_free;
+	struct quicklist *q;
+
+	q = &get_cpu_var(quicklist)[nr];
+	if (q->nr_pages > min_pages) {
+		pages_to_free = min_pages_to_free(q, min_pages, max_free);
+
+		while (pages_to_free > 0) {
+			/*
+			 * We pass a gfp_t of 0 to quicklist_alloc here
+			 * because we will never call into the page allocator.
+			 */
+			void *p = quicklist_alloc(nr, 0, NULL);
+
+			if (dtor)
+				dtor(p);
+			free_page((unsigned long)p);
+			pages_to_free--;
+		}
+	}
+	put_cpu_var(quicklist);
+}
+
+unsigned long quicklist_total_size(void)
+{
+	unsigned long count = 0;
+	int cpu;
+	struct quicklist *ql, *q;
+
+	for_each_online_cpu(cpu) {
+		ql = per_cpu(quicklist, cpu);
+		for (q = ql; q < ql + CONFIG_NR_QUICK; q++)
+			count += q->nr_pages;
+	}
+	return count;
+}
+