From: "Aneesh Kumar K.V" <aneesh.kumar@xxxxxxxxxxxxxxxxxx>
This patch moves the hugetlbfs region tracking function to
common code. We will be using this in later patches in the
series.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxxxxxxx>
---
include/linux/region.h | 28 +++++++++
mm/Makefile | 2 +-
mm/region.c | 158 ++++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 187 insertions(+), 1 deletions(-)
create mode 100644 include/linux/region.h
create mode 100644 mm/region.c
diff --git a/include/linux/region.h b/include/linux/region.h
new file mode 100644
index 0000000..a8a5b46
--- /dev/null
+++ b/include/linux/region.h
@@ -0,0 +1,28 @@
+/*
+ * Copyright IBM Corporation, 2012
+ * Author Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of version 2.1 of the GNU Lesser General Public License
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it would be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ */
+
+#ifndef _LINUX_REGION_H
+#define _LINUX_REGION_H
+
+struct file_region {
+ struct list_head link;
+ long from;
+ long to;
+};
+
+extern long region_add(struct list_head *head, long from, long to);
+extern long region_chg(struct list_head *head, long from, long to);
+extern long region_truncate(struct list_head *head, long end);
+extern long region_count(struct list_head *head, long from, long to);
+#endif
diff --git a/mm/Makefile b/mm/Makefile
index 50ec00e..8828a1b 100644
--- a/mm/Makefile
+++ b/mm/Makefile
@@ -14,7 +14,7 @@ obj-y := filemap.o mempool.o oom_kill.o fadvise.o \
prio_tree.o util.o mmzone.o vmstat.o backing-dev.o \
page_isolation.o mm_init.o mmu_context.o percpu.o \
$(mmu-y)
-obj-y += init-mm.o
+obj-y += init-mm.o region.o
ifdef CONFIG_NO_BOOTMEM
obj-y += nobootmem.o
diff --git a/mm/region.c b/mm/region.c
new file mode 100644
index 0000000..ab59fe7
--- /dev/null
+++ b/mm/region.c
@@ -0,0 +1,158 @@
+/*
+ * Copyright IBM Corporation, 2012
+ * Author Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of version 2.1 of the GNU Lesser General Public License
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it would be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ */
+
+#include <linux/cgroup.h>
+#include <linux/slab.h>
+#include <linux/hugetlb.h>
+#include <linux/list.h>
+#include <linux/region.h>
+
+long region_add(struct list_head *head, long from, long to)
+{
+ struct file_region *rg, *nrg, *trg;
+
+ /* Locate the region we are either in or before. */
+ list_for_each_entry(rg, head, link)
+ if (from <= rg->to)
+ break;
+
+ /* Round our left edge to the current segment if it encloses us. */
+ if (from > rg->from)
+ from = rg->from;
+
+ /* Check for and consume any regions we now overlap with. */
+ nrg = rg;
+ list_for_each_entry_safe(rg, trg, rg->link.prev, link) {
+ if (&rg->link == head)
+ break;
+ if (rg->from > to)
+ break;
+
+ /* If this area reaches higher then extend our area to
+ * include it completely. If this is not the first area
+ * which we intend to reuse, free it. */
+ if (rg->to > to)
+ to = rg->to;
+ if (rg != nrg) {
+ list_del(&rg->link);
+ kfree(rg);
+ }
+ }
+ nrg->from = from;
+ nrg->to = to;
+ return 0;
+}
+
+long region_chg(struct list_head *head, long from, long to)
+{
+ struct file_region *rg, *nrg;
+ long chg = 0;
+
+ /* Locate the region we are before or in. */
+ list_for_each_entry(rg, head, link)
+ if (from <= rg->to)
+ break;
+
+ /* If we are below the current region then a new region is required.
+ * Subtle, allocate a new region at the position but make it zero
+ * size such that we can guarantee to record the reservation. */
+ if (&rg->link == head || to < rg->from) {
+ nrg = kmalloc(sizeof(*nrg), GFP_KERNEL);
+ if (!nrg)
+ return -ENOMEM;
+ nrg->from = from;
+ nrg->to = from;
+ INIT_LIST_HEAD(&nrg->link);
+ list_add(&nrg->link, rg->link.prev);
+
+ return to - from;
+ }
+
+ /* Round our left edge to the current segment if it encloses us. */
+ if (from > rg->from)
+ from = rg->from;
+ chg = to - from;
+
+ /* Check for and consume any regions we now overlap with. */
+ list_for_each_entry(rg, rg->link.prev, link) {
+ if (&rg->link == head)
+ break;
+ if (rg->from > to)
+ return chg;
+
+ /* We overlap with this area, if it extends further than
+ * us then we must extend ourselves. Account for its
+ * existing reservation. */
+ if (rg->to > to) {
+ chg += rg->to - to;
+ to = rg->to;
+ }
+ chg -= rg->to - rg->from;
+ }
+ return chg;
+}
+
+long region_truncate(struct list_head *head, long end)
+{
+ struct file_region *rg, *trg;
+ long chg = 0;
+
+ /* Locate the region we are either in or before. */
+ list_for_each_entry(rg, head, link)
+ if (end <= rg->to)
+ break;
+ if (&rg->link == head)
+ return 0;
+
+ /* If we are in the middle of a region then adjust it. */
+ if (end > rg->from) {
+ chg = rg->to - end;
+ rg->to = end;
+ rg = list_entry(rg->link.next, typeof(*rg), link);
+ }
+
+ /* Drop any remaining regions. */
+ list_for_each_entry_safe(rg, trg, rg->link.prev, link) {
+ if (&rg->link == head)
+ break;
+ chg += rg->to - rg->from;
+ list_del(&rg->link);
+ kfree(rg);
+ }
+ return chg;
+}
+
+long region_count(struct list_head *head, long from, long to)
+{
+ struct file_region *rg;
+ long chg = 0;
+
+ /* Locate each segment we overlap with, and count that overlap. */
+ list_for_each_entry(rg, head, link) {
+ int seg_from;
+ int seg_to;
+
+ if (rg->to <= from)
+ continue;
+ if (rg->from >= to)
+ break;
+
+ seg_from = max(rg->from, from);
+ seg_to = min(rg->to, to);
+
+ chg += seg_to - seg_from;
+ }
+
+ return chg;
+}
--
1.7.9
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