Hi,

This patch implements the bio cgroup on the memory cgroup.

Signed-off-by: Hirokazu Takahashi <taka@valinux.co.jp>


--- linux-2.6.25-rc5.pagecgroup2/include/linux/memcontrol.h	2008-03-18 12:45:14.000000000 +0900
+++ linux-2.6.25-rc5-mm1/include/linux/memcontrol.h	2008-03-18 12:55:59.000000000 +0900
@@ -54,6 +54,10 @@ struct page_cgroup {
 	struct list_head lru;		/* per cgroup LRU list */
 	struct mem_cgroup *mem_cgroup;
 #endif /* CONFIG_CGROUP_MEM_RES_CTLR */
+#ifdef  CONFIG_CGROUP_BIO
+	struct list_head blist;		/* for bio_cgroup page list */
+	struct bio_cgroup *bio_cgroup;
+#endif
 	struct page *page;
 	int ref_cnt;			/* cached, mapped, migrating */
 	int flags;
--- linux-2.6.25-rc5.pagecgroup2/include/linux/biocontrol.h	2008-03-17 22:06:49.000000000 +0900
+++ linux-2.6.25-rc5-mm1/include/linux/biocontrol.h	2008-03-18 14:19:53.000000000 +0900
@@ -0,0 +1,148 @@
+#include <linux/cgroup.h>
+#include <linux/mm.h>
+#include <linux/memcontrol.h>
+
+#ifndef _LINUX_BIOCONTROL_H
+#define _LINUX_BIOCONTROL_H
+
+#ifdef	CONFIG_CGROUP_BIO
+
+struct io_context;
+
+struct bio_cgroup {
+	struct cgroup_subsys_state css;
+	int id;
+	struct io_context *io_context;	/* default io_context */
+/*	struct radix_tree_root io_context_root; per device io_context */
+	spinlock_t		page_list_lock;
+	struct list_head	page_list;
+};
+
+static inline int bio_cgroup_disabled(void)
+{
+	return bio_cgroup_subsys.disabled;
+}
+
+extern void mm_init_bio_cgroup(struct mm_struct *, struct task_struct *);
+
+static inline void __bio_cgroup_add_page(struct page_cgroup *pc)
+{
+	struct bio_cgroup *biog = pc->bio_cgroup;
+	list_add(&pc->blist, &biog->page_list);
+}
+
+static inline void bio_cgroup_add_page(struct page_cgroup *pc)
+{
+	struct bio_cgroup *biog = pc->bio_cgroup;
+	unsigned long flags;
+	spin_lock_irqsave(&biog->page_list_lock, flags);
+	__bio_cgroup_add_page(pc);
+	spin_unlock_irqrestore(&biog->page_list_lock, flags);
+}
+
+static inline void __bio_cgroup_remove_page(struct page_cgroup *pc)
+{
+	list_del_init(&pc->blist);
+}
+
+static inline void bio_cgroup_remove_page(struct page_cgroup *pc)
+{
+	struct bio_cgroup *biog = pc->bio_cgroup;
+	unsigned long flags;
+	spin_lock_irqsave(&biog->page_list_lock, flags);
+	__bio_cgroup_remove_page(pc);
+	spin_unlock_irqrestore(&biog->page_list_lock, flags);
+}
+
+static inline void get_bio_cgroup(struct bio_cgroup *biog)
+{
+	css_get(&biog->css);
+}
+
+static inline void put_bio_cgroup(struct bio_cgroup *biog)
+{
+	css_put(&biog->css);
+}
+
+static inline void set_bio_cgroup(struct page_cgroup *pc,
+					struct bio_cgroup *biog)
+{
+	pc->bio_cgroup = biog;
+}
+
+static inline void clear_bio_cgroup(struct page_cgroup *pc)
+{
+	struct bio_cgroup *biog = pc->bio_cgroup;
+	pc->bio_cgroup = NULL;
+	put_bio_cgroup(biog);
+}
+
+/* This sould be called in an RCU-protected section. */
+static inline struct bio_cgroup *mm_get_bio_cgroup(struct mm_struct *mm)
+{
+	struct bio_cgroup *biog = rcu_dereference(mm->bio_cgroup);
+	get_bio_cgroup(biog);
+	return biog;
+}
+
+static inline void mm_free_bio_cgroup(struct mm_struct *mm)
+{
+	put_bio_cgroup(mm->bio_cgroup);
+}
+
+extern int get_bio_cgroup_id(struct page *page);
+
+#else	/* CONFIG_CGROUP_BIO */
+
+struct bio_cgroup;
+
+static inline int bio_cgroup_disabled(void)
+{
+        return 1;
+}
+
+static inline void mm_init_bio_cgroup(struct mm_struct *mm, struct task_struct *p)
+{
+}
+
+static inline void bio_cgroup_add_page(struct page_cgroup *pc)
+{
+}
+
+static inline void bio_cgroup_remove_page(struct page_cgroup *pc)
+{
+}
+
+static inline void get_bio_cgroup(struct bio_cgroup *biog)
+{
+}
+
+static inline void put_bio_cgroup(struct bio_cgroup *biog)
+{
+}
+
+static inline void set_bio_cgroup(struct page_cgroup *pc,
+					struct bio_cgroup *biog)
+{
+}
+
+static inline void clear_bio_cgroup(struct page_cgroup *pc)
+{
+}
+
+static inline struct bio_cgroup *mm_get_bio_cgroup(struct mm_struct *mm)
+{
+	return NULL;
+}
+
+static inline void mm_free_bio_cgroup(struct mm_struct *mm)
+{
+}
+
+static inline int get_bio_cgroup_id(struct page *page)
+{
+	return 0;
+}
+#endif	/* CONFIG_CGROUP_BIO */
+
+#endif /* _LINUX_BIOCONTROL_H */
--- linux-2.6.25-rc5.pagecgroup2/include/linux/cgroup_subsys.h	2008-03-18 12:45:14.000000000 +0900
+++ linux-2.6.25-rc5-mm1/include/linux/cgroup_subsys.h	2008-03-18 12:55:59.000000000 +0900
@@ -42,3 +42,9 @@ SUBSYS(mem_cgroup)
 #endif
 
 /* */
+
+#ifdef CONFIG_CGROUP_BIO
+SUBSYS(bio_cgroup)
+#endif
+
+/* */
--- linux-2.6.25-rc5.pagecgroup2/include/linux/mm_types.h	2008-03-18 12:45:14.000000000 +0900
+++ linux-2.6.25-rc5-mm1/include/linux/mm_types.h	2008-03-18 12:55:59.000000000 +0900
@@ -230,6 +230,9 @@ struct mm_struct {
 #ifdef CONFIG_CGROUP_MEM_RES_CTLR
 	struct mem_cgroup *mem_cgroup;
 #endif
+#ifdef CONFIG_CGROUP_BIO
+	struct bio_cgroup *bio_cgroup;
+#endif
 
 #ifdef CONFIG_PROC_FS
 	/* store ref to file /proc/<pid>/exe symlink points to */
--- linux-2.6.25-rc5.pagecgroup2/init/Kconfig	2008-03-18 12:45:14.000000000 +0900
+++ linux-2.6.25-rc5-mm1/init/Kconfig	2008-03-18 12:55:59.000000000 +0900
@@ -379,9 +379,15 @@ config CGROUP_MEM_RES_CTLR
 	  Only enable when you're ok with these trade offs and really
 	  sure you need the memory resource controller.
 
+config CGROUP_BIO
+        bool "Block I/O cgroup subsystem"
+        depends on CGROUPS
+        help
+          Provides a Resource Controller that manages Block I/O.
+
 config CGROUP_PAGE
         def_bool y
-        depends on CGROUP_MEM_RES_CTLR
+        depends on CGROUP_MEM_RES_CTLR || CGROUP_BIO
 
 config SYSFS_DEPRECATED
 	bool
--- linux-2.6.25-rc5.pagecgroup2/mm/Makefile	2008-03-18 12:45:14.000000000 +0900
+++ linux-2.6.25-rc5-mm1/mm/Makefile	2008-03-18 12:55:59.000000000 +0900
@@ -33,4 +33,5 @@ obj-$(CONFIG_MIGRATION) += migrate.o
 obj-$(CONFIG_SMP) += allocpercpu.o
 obj-$(CONFIG_QUICKLIST) += quicklist.o
 obj-$(CONFIG_CGROUP_PAGE) += memcontrol.o
+obj-$(CONFIG_CGROUP_BIO) += biocontrol.o
 
--- linux-2.6.25-rc5.pagecgroup2/mm/biocontrol.c	2008-03-17 22:06:49.000000000 +0900
+++ linux-2.6.25-rc5-mm1/mm/biocontrol.c	2008-03-18 12:55:59.000000000 +0900
@@ -0,0 +1,229 @@
+/* biocontrol.c - Block I/O Controller
+ *
+ * Copyright VA Linux Systems Japan, 2008
+ * Author Hirokazu Takahashi <taka@valinux.co.jp>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/module.h>
+#include <linux/cgroup.h>
+#include <linux/mm.h>
+#include <linux/smp.h>
+#include <linux/bit_spinlock.h>
+#include <linux/idr.h>
+#include <linux/err.h>
+#include <linux/biocontrol.h>
+
+/* return corresponding bio_cgroup object of a cgroup */
+static inline struct bio_cgroup *cgroup_bio(struct cgroup *cgrp)
+{
+	return container_of(cgroup_subsys_state(cgrp, bio_cgroup_subsys_id),
+			    struct bio_cgroup, css);
+}
+
+static inline struct bio_cgroup *bio_cgroup_from_task(struct task_struct *p)
+{
+	return container_of(task_subsys_state(p, bio_cgroup_subsys_id),
+				struct bio_cgroup, css);
+}
+
+void mm_init_bio_cgroup(struct mm_struct *mm, struct task_struct *p)
+{
+	struct bio_cgroup *biog;
+
+	biog = bio_cgroup_from_task(p);
+	get_bio_cgroup(biog);
+	mm->bio_cgroup = biog;
+}
+
+static struct idr bio_cgroup_id;
+static DEFINE_SPINLOCK(bio_cgroup_idr_lock);
+
+static struct cgroup_subsys_state *
+bio_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cgrp)
+{
+	struct bio_cgroup *biog;
+	int error;
+
+	biog = kzalloc(sizeof(*biog), GFP_KERNEL);
+	if (!biog)
+		return ERR_PTR(-ENOMEM);
+	if (!cgrp->parent) {
+		init_mm.bio_cgroup = biog;
+		idr_init(&bio_cgroup_id);
+		biog->id = 0;
+	} else {
+retry:
+		if (unlikely(!idr_pre_get(&bio_cgroup_id, GFP_KERNEL))) {
+			error = -EAGAIN;
+			goto out;
+		}
+		spin_lock_irq(&bio_cgroup_idr_lock);
+		error = idr_get_new_above(&bio_cgroup_id, (void *)biog, 1, &biog->id);
+		spin_unlock_irq(&bio_cgroup_idr_lock);
+		if (error == -EAGAIN)
+			goto retry;
+		else if (error)
+			goto out;
+	}
+
+	INIT_LIST_HEAD(&biog->page_list);
+	spin_lock_init(&biog->page_list_lock);
+
+	/* Bind the cgroup to bio_cgroup object we just created */
+	biog->css.cgroup = cgrp;
+
+	return &biog->css;
+out:
+	kfree(biog);
+	return ERR_PTR(error);
+}
+
+#define FORCE_UNCHARGE_BATCH	(128)
+static void bio_cgroup_force_empty(struct bio_cgroup *biog)
+{
+	struct page_cgroup *pc;
+	struct page *page;
+	int count = FORCE_UNCHARGE_BATCH;
+	struct list_head *list = &biog->page_list;
+	unsigned long flags;
+
+	spin_lock_irqsave(&biog->page_list_lock, flags);
+	while (!list_empty(list)) {
+		pc = list_entry(list->prev, struct page_cgroup, blist);
+		page = pc->page;
+		get_page(page);
+		spin_unlock_irqrestore(&biog->page_list_lock, flags);
+		mem_cgroup_uncharge_page(page);
+		put_page(page);
+		if (--count <= 0) {
+			count = FORCE_UNCHARGE_BATCH;
+			cond_resched();
+		}
+		spin_lock_irqsave(&biog->page_list_lock, flags);
+	}
+	spin_unlock_irqrestore(&biog->page_list_lock, flags);
+	return;
+}
+
+static void bio_cgroup_pre_destroy(struct cgroup_subsys *ss, struct cgroup *cgrp)
+{
+	struct bio_cgroup *biog = cgroup_bio(cgrp);
+	bio_cgroup_force_empty(biog);
+}
+
+static void bio_cgroup_destroy(struct cgroup_subsys *ss, struct cgroup *cgrp)
+{
+	struct bio_cgroup *biog = cgroup_bio(cgrp);
+
+        spin_lock_irq(&bio_cgroup_idr