[PATCH 5/9] blkio-cgroup-v9: The body of blkio-cgroup

From: Ryo Tsuruta
Date: Tue Jul 21 2009 - 10:14:15 EST


The body of blkio-cgroup.

Signed-off-by: Hirokazu Takahashi <taka@xxxxxxxxxxxxx>
Signed-off-by: Ryo Tsuruta <ryov@xxxxxxxxxxxxx>

---
include/linux/biotrack.h | 97 +++++++++++++
include/linux/cgroup_subsys.h | 6
include/linux/page_cgroup.h | 23 +++
init/Kconfig | 13 +
mm/Makefile | 1
mm/biotrack.c | 300 ++++++++++++++++++++++++++++++++++++++++++
mm/page_cgroup.c | 20 +-
7 files changed, 451 insertions(+), 9 deletions(-)

Index: linux-2.6.31-rc3/include/linux/biotrack.h
===================================================================
--- /dev/null
+++ linux-2.6.31-rc3/include/linux/biotrack.h
@@ -0,0 +1,97 @@
+#include <linux/cgroup.h>
+#include <linux/mm.h>
+#include <linux/page_cgroup.h>
+
+#ifndef _LINUX_BIOTRACK_H
+#define _LINUX_BIOTRACK_H
+
+#ifdef CONFIG_CGROUP_BLKIO
+
+struct io_context;
+struct block_device;
+
+struct blkio_cgroup {
+ struct cgroup_subsys_state css;
+ struct io_context *io_context; /* default io_context */
+/* struct radix_tree_root io_context_root; per device io_context */
+};
+
+/**
+ * __init_blkio_page_cgroup() - initialize a blkio_page_cgroup
+ * @pc: page_cgroup of the page
+ *
+ * Reset the owner ID of a page.
+ */
+static inline void __init_blkio_page_cgroup(struct page_cgroup *pc)
+{
+ lock_page_cgroup(pc);
+ page_cgroup_set_id(pc, 0);
+ unlock_page_cgroup(pc);
+}
+
+/**
+ * blkio_cgroup_disabled() - check whether blkio_cgroup is disabled
+ *
+ * Returns true if disabled, false if not.
+ */
+static inline bool blkio_cgroup_disabled(void)
+{
+ if (blkio_cgroup_subsys.disabled)
+ return true;
+ return false;
+}
+
+extern void blkio_cgroup_set_owner(struct page *page, struct mm_struct *mm);
+extern void blkio_cgroup_reset_owner(struct page *page, struct mm_struct *mm);
+extern void blkio_cgroup_reset_owner_pagedirty(struct page *page,
+ struct mm_struct *mm);
+extern void blkio_cgroup_copy_owner(struct page *page, struct page *opage);
+
+extern struct io_context *get_blkio_cgroup_iocontext(struct bio *bio);
+extern unsigned long get_blkio_cgroup_id(struct bio *bio);
+extern struct cgroup *blkio_cgroup_lookup(int id);
+
+#else /* !CONFIG_CGROUP_BLKIO */
+
+struct blkio_cgroup;
+
+static inline void __init_blkio_page_cgroup(struct page_cgroup *pc)
+{
+}
+
+static inline bool blkio_cgroup_disabled(void)
+{
+ return true;
+}
+
+static inline void blkio_cgroup_set_owner(struct page *page, struct mm_struct *mm)
+{
+}
+
+static inline void blkio_cgroup_reset_owner(struct page *page,
+ struct mm_struct *mm)
+{
+}
+
+static inline void blkio_cgroup_reset_owner_pagedirty(struct page *page,
+ struct mm_struct *mm)
+{
+}
+
+static inline void blkio_cgroup_copy_owner(struct page *page, struct page *opage)
+{
+}
+
+static inline struct io_context *get_blkio_cgroup_iocontext(struct bio *bio)
+{
+ return NULL;
+}
+
+static inline unsigned long get_blkio_cgroup_id(struct bio *bio)
+{
+ return 0;
+}
+
+#endif /* CONFIG_CGROUP_BLKIO */
+
+#endif /* _LINUX_BIOTRACK_H */
Index: linux-2.6.31-rc3/include/linux/cgroup_subsys.h
===================================================================
--- linux-2.6.31-rc3.orig/include/linux/cgroup_subsys.h
+++ linux-2.6.31-rc3/include/linux/cgroup_subsys.h
@@ -43,6 +43,12 @@ SUBSYS(mem_cgroup)

/* */

+#ifdef CONFIG_CGROUP_BLKIO
+SUBSYS(blkio_cgroup)
+#endif
+
+/* */
+
#ifdef CONFIG_CGROUP_DEVICE
SUBSYS(devices)
#endif
Index: linux-2.6.31-rc3/include/linux/page_cgroup.h
===================================================================
--- linux-2.6.31-rc3.orig/include/linux/page_cgroup.h
+++ linux-2.6.31-rc3/include/linux/page_cgroup.h
@@ -140,4 +140,27 @@ static inline void swap_cgroup_swapoff(i
}

#endif
+
+#ifdef CONFIG_CGROUP_BLKIO
+/*
+ * use lower 16 bits for flags and reserve the rest for the page tracking id
+ */
+#define PCG_TRACKING_ID_SHIFT (16)
+#define PCG_TRACKING_ID_BITS \
+ (8 * sizeof(unsigned long) - PCG_TRACKING_ID_SHIFT)
+
+/* NOTE: must be called with page_cgroup() held */
+static inline unsigned long page_cgroup_get_id(struct page_cgroup *pc)
+{
+ return pc->flags >> PCG_TRACKING_ID_SHIFT;
+}
+
+/* NOTE: must be called with page_cgroup() held */
+static inline void page_cgroup_set_id(struct page_cgroup *pc, unsigned long id)
+{
+ WARN_ON(id >= (1UL << PCG_TRACKING_ID_BITS));
+ pc->flags &= (1UL << PCG_TRACKING_ID_SHIFT) - 1;
+ pc->flags |= (unsigned long)(id << PCG_TRACKING_ID_SHIFT);
+}
+#endif
#endif
Index: linux-2.6.31-rc3/init/Kconfig
===================================================================
--- linux-2.6.31-rc3.orig/init/Kconfig
+++ linux-2.6.31-rc3/init/Kconfig
@@ -614,9 +614,20 @@ config CGROUP_MEM_RES_CTLR_SWAP

endif # CGROUPS

+config CGROUP_BLKIO
+ bool "Block I/O cgroup subsystem"
+ depends on CGROUPS && BLOCK
+ select MM_OWNER
+ help
+ Provides a Resource Controller which enables to track the onwner
+ of every Block I/O requests.
+ The information this subsystem provides can be used from any
+ kind of module such as dm-ioband device mapper modules or
+ the cfq-scheduler.
+
config CGROUP_PAGE
def_bool y
- depends on CGROUP_MEM_RES_CTLR
+ depends on CGROUP_MEM_RES_CTLR || CGROUP_BLKIO

config MM_OWNER
bool
Index: linux-2.6.31-rc3/mm/biotrack.c
===================================================================
--- /dev/null
+++ linux-2.6.31-rc3/mm/biotrack.c
@@ -0,0 +1,300 @@
+/* biotrack.c - Block I/O Tracking
+ *
+ * Copyright (C) VA Linux Systems Japan, 2008-2009
+ * Developed by Hirokazu Takahashi <taka@xxxxxxxxxxxxx>
+ *
+ * Copyright (C) 2008 Andrea Righi <righi.andrea@xxxxxxxxx>
+ * Use part of page_cgroup->flags to store blkio-cgroup ID.
+ *
+ * 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/smp.h>
+#include <linux/bit_spinlock.h>
+#include <linux/blkdev.h>
+#include <linux/biotrack.h>
+#include <linux/mm_inline.h>
+
+/*
+ * The block I/O tracking mechanism is implemented on the cgroup memory
+ * controller framework. It helps to find the the owner of an I/O request
+ * because every I/O request has a target page and the owner of the page
+ * can be easily determined on the framework.
+ */
+
+/* Return the blkio_cgroup that associates with a cgroup. */
+static inline struct blkio_cgroup *cgroup_blkio(struct cgroup *cgrp)
+{
+ return container_of(cgroup_subsys_state(cgrp, blkio_cgroup_subsys_id),
+ struct blkio_cgroup, css);
+}
+
+/* Return the blkio_cgroup that associates with a process. */
+static inline struct blkio_cgroup *blkio_cgroup_from_task(struct task_struct *p)
+{
+ return container_of(task_subsys_state(p, blkio_cgroup_subsys_id),
+ struct blkio_cgroup, css);
+}
+
+static struct io_context default_blkio_io_context;
+static struct blkio_cgroup default_blkio_cgroup = {
+ .io_context = &default_blkio_io_context,
+};
+
+/**
+ * blkio_cgroup_set_owner() - set the owner ID of a page.
+ * @page: the page we want to tag
+ * @mm: the mm_struct of a page owner
+ *
+ * Make a given page have the blkio-cgroup ID of the owner of this page.
+ */
+void blkio_cgroup_set_owner(struct page *page, struct mm_struct *mm)
+{
+ struct blkio_cgroup *biog;
+ struct page_cgroup *pc;
+ unsigned long id;
+
+ if (blkio_cgroup_disabled())
+ return;
+ pc = lookup_page_cgroup(page);
+ if (unlikely(!pc))
+ return;
+
+ lock_page_cgroup(pc);
+ page_cgroup_set_id(pc, 0); /* 0: default blkio_cgroup id */
+ unlock_page_cgroup(pc);
+ if (!mm)
+ return;
+
+ rcu_read_lock();
+ biog = blkio_cgroup_from_task(rcu_dereference(mm->owner));
+ if (unlikely(!biog)) {
+ rcu_read_unlock();
+ return;
+ }
+ /*
+ * css_get(&bio->css) isn't called to increment the reference
+ * count of this blkio_cgroup "biog" so the css_id might turn
+ * invalid even if this page is still active.
+ * This approach is chosen to minimize the overhead.
+ */
+ id = css_id(&biog->css);
+ rcu_read_unlock();
+ lock_page_cgroup(pc);
+ page_cgroup_set_id(pc, id);
+ unlock_page_cgroup(pc);
+}
+
+/**
+ * blkio_cgroup_reset_owner() - reset the owner ID of a page
+ * @page: the page we want to tag
+ * @mm: the mm_struct of a page owner
+ *
+ * Change the owner of a given page if necessary.
+ */
+void blkio_cgroup_reset_owner(struct page *page, struct mm_struct *mm)
+{
+ blkio_cgroup_set_owner(page, mm);
+}
+
+/**
+ * blkio_cgroup_reset_owner_pagedirty() - reset the owner ID of a pagecache page
+ * @page: the page we want to tag
+ * @mm: the mm_struct of a page owner
+ *
+ * Change the owner of a given page if the page is in the pagecache.
+ */
+void blkio_cgroup_reset_owner_pagedirty(struct page *page, struct mm_struct *mm)
+{
+ if (!page_is_file_cache(page))
+ return;
+ if (current->flags & PF_MEMALLOC)
+ return;
+
+ blkio_cgroup_reset_owner(page, mm);
+}
+
+/**
+ * blkio_cgroup_copy_owner() - copy the owner ID of a page into another page
+ * @npage: the page where we want to copy the owner
+ * @opage: the page from which we want to copy the ID
+ *
+ * Copy the owner ID of @opage into @npage.
+ */
+void blkio_cgroup_copy_owner(struct page *npage, struct page *opage)
+{
+ struct page_cgroup *npc, *opc;
+ unsigned long id;
+
+ if (blkio_cgroup_disabled())
+ return;
+ npc = lookup_page_cgroup(npage);
+ if (unlikely(!npc))
+ return;
+ opc = lookup_page_cgroup(opage);
+ if (unlikely(!opc))
+ return;
+
+ lock_page_cgroup(opc);
+ lock_page_cgroup(npc);
+ id = page_cgroup_get_id(opc);
+ page_cgroup_set_id(npc, id);
+ unlock_page_cgroup(npc);
+ unlock_page_cgroup(opc);
+}
+
+/* Create a new blkio-cgroup. */
+static struct cgroup_subsys_state *
+blkio_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cgrp)
+{
+ struct blkio_cgroup *biog;
+ struct io_context *ioc;
+
+ if (!cgrp->parent) {
+ biog = &default_blkio_cgroup;
+ init_io_context(biog->io_context);
+ /* Increment the referrence count not to be released ever. */
+ atomic_inc(&biog->io_context->refcount);
+ return &biog->css;
+ }
+
+ biog = kzalloc(sizeof(*biog), GFP_KERNEL);
+ if (!biog)
+ return ERR_PTR(-ENOMEM);
+ ioc = alloc_io_context(GFP_KERNEL, -1);
+ if (!ioc) {
+ kfree(biog);
+ return ERR_PTR(-ENOMEM);
+ }
+ biog->io_context = ioc;
+ return &biog->css;
+}
+
+/* Delete the blkio-cgroup. */
+static void blkio_cgroup_destroy(struct cgroup_subsys *ss, struct cgroup *cgrp)
+{
+ struct blkio_cgroup *biog = cgroup_blkio(cgrp);
+
+ put_io_context(biog->io_context);
+ free_css_id(&blkio_cgroup_subsys, &biog->css);
+ kfree(biog);
+}
+
+/**
+ * get_blkio_cgroup_id() - determine the blkio-cgroup ID
+ * @bio: the &struct bio which describes the I/O
+ *
+ * Returns the blkio-cgroup ID of a given bio. A return value zero
+ * means that the page associated with the bio belongs to default_blkio_cgroup.
+ */
+unsigned long get_blkio_cgroup_id(struct bio *bio)
+{
+ struct page_cgroup *pc;
+ struct page *page = bio_iovec_idx(bio, 0)->bv_page;
+ unsigned long id = 0;
+
+ pc = lookup_page_cgroup(page);
+ if (pc) {
+ lock_page_cgroup(pc);
+ id = page_cgroup_get_id(pc);
+ unlock_page_cgroup(pc);
+ }
+ return id;
+}
+
+/**
+ * get_blkio_cgroup_iocontext() - determine the blkio-cgroup iocontext
+ * @bio: the &struct bio which describe the I/O
+ *
+ * Returns the iocontext of blkio-cgroup that issued a given bio.
+ */
+struct io_context *get_blkio_cgroup_iocontext(struct bio *bio)
+{
+ struct cgroup_subsys_state *css;
+ struct blkio_cgroup *biog;
+ struct io_context *ioc;
+ unsigned long id;
+
+ id = get_blkio_cgroup_id(bio);
+ rcu_read_lock();
+ css = css_lookup(&blkio_cgroup_subsys, id);
+ if (css)
+ biog = container_of(css, struct blkio_cgroup, css);
+ else
+ biog = &default_blkio_cgroup;
+ ioc = biog->io_context; /* default io_context for this cgroup */
+ atomic_inc(&ioc->refcount);
+ rcu_read_unlock();
+ return ioc;
+}
+
+/**
+ * blkio_cgroup_lookup() - lookup a cgroup by blkio-cgroup ID
+ * @id: blkio-cgroup ID
+ *
+ * Returns the cgroup associated with the specified ID, or NULL if lookup
+ * fails.
+ *
+ * Note:
+ * This function should be called under rcu_read_lock().
+ */
+struct cgroup *blkio_cgroup_lookup(int id)
+{
+ struct cgroup *cgrp;
+ struct cgroup_subsys_state *css;
+
+ if (blkio_cgroup_disabled())
+ return NULL;
+
+ css = css_lookup(&blkio_cgroup_subsys, id);
+ if (!css)
+ return NULL;
+ cgrp = css->cgroup;
+ return cgrp;
+}
+EXPORT_SYMBOL(get_blkio_cgroup_iocontext);
+EXPORT_SYMBOL(get_blkio_cgroup_id);
+EXPORT_SYMBOL(blkio_cgroup_lookup);
+
+static u64 blkio_id_read(struct cgroup *cgrp, struct cftype *cft)
+{
+ struct blkio_cgroup *biog = cgroup_blkio(cgrp);
+ unsigned long id;
+
+ rcu_read_lock();
+ id = css_id(&biog->css);
+ rcu_read_unlock();
+ return (u64)id;
+}
+
+
+static struct cftype blkio_files[] = {
+ {
+ .name = "id",
+ .read_u64 = blkio_id_read,
+ },
+};
+
+static int blkio_cgroup_populate(struct cgroup_subsys *ss, struct cgroup *cgrp)
+{
+ return cgroup_add_files(cgrp, ss, blkio_files,
+ ARRAY_SIZE(blkio_files));
+}
+
+struct cgroup_subsys blkio_cgroup_subsys = {
+ .name = "blkio",
+ .create = blkio_cgroup_create,
+ .destroy = blkio_cgroup_destroy,
+ .populate = blkio_cgroup_populate,
+ .subsys_id = blkio_cgroup_subsys_id,
+ .use_id = 1,
+};
Index: linux-2.6.31-rc3/mm/page_cgroup.c
===================================================================
--- linux-2.6.31-rc3.orig/mm/page_cgroup.c
+++ linux-2.6.31-rc3/mm/page_cgroup.c
@@ -9,6 +9,7 @@
#include <linux/vmalloc.h>
#include <linux/cgroup.h>
#include <linux/swapops.h>
+#include <linux/biotrack.h>

static void __meminit
__init_page_cgroup(struct page_cgroup *pc, unsigned long pfn)
@@ -16,6 +17,7 @@ __init_page_cgroup(struct page_cgroup *p
pc->flags = 0;
pc->page = pfn_to_page(pfn);
__init_mem_page_cgroup(pc);
+ __init_blkio_page_cgroup(pc);
}
static unsigned long total_usage;

@@ -73,7 +75,7 @@ void __init page_cgroup_init_flatmem(voi

int nid, fail;

- if (mem_cgroup_disabled())
+ if (mem_cgroup_disabled() && blkio_cgroup_disabled())
return;

for_each_online_node(nid) {
@@ -82,12 +84,13 @@ void __init page_cgroup_init_flatmem(voi
goto fail;
}
printk(KERN_INFO "allocated %ld bytes of page_cgroup\n", total_usage);
- printk(KERN_INFO "please try 'cgroup_disable=memory' option if you"
- " don't want memory cgroups\n");
+ printk(KERN_INFO "please try 'cgroup_disable=memory,blkio' option"
+ " if you don't want memory and blkio cgroups\n");
return;
fail:
printk(KERN_CRIT "allocation of page_cgroup failed.\n");
- printk(KERN_CRIT "please try 'cgroup_disable=memory' boot option\n");
+ printk(KERN_CRIT
+ "please try 'cgroup_disable=memory,blkio' boot option\n");
panic("Out of memory");
}

@@ -244,7 +247,7 @@ void __init page_cgroup_init(void)
unsigned long pfn;
int fail = 0;

- if (mem_cgroup_disabled())
+ if (mem_cgroup_disabled() && blkio_cgroup_disabled())
return;

for (pfn = 0; !fail && pfn < max_pfn; pfn += PAGES_PER_SECTION) {
@@ -253,14 +256,15 @@ void __init page_cgroup_init(void)
fail = init_section_page_cgroup(pfn);
}
if (fail) {
- printk(KERN_CRIT "try 'cgroup_disable=memory' boot option\n");
+ printk(KERN_CRIT
+ "try 'cgroup_disable=memory,blkio' boot option\n");
panic("Out of memory");
} else {
hotplug_memory_notifier(page_cgroup_callback, 0);
}
printk(KERN_INFO "allocated %ld bytes of page_cgroup\n", total_usage);
- printk(KERN_INFO "please try 'cgroup_disable=memory' option if you don't"
- " want memory cgroups\n");
+ printk(KERN_INFO "please try 'cgroup_disable=memory,blkio' option"
+ " if you don't want memory and blkio cgroups\n");
}

void __meminit pgdat_page_cgroup_init(struct pglist_data *pgdat)
Index: linux-2.6.31-rc3/mm/Makefile
===================================================================
--- linux-2.6.31-rc3.orig/mm/Makefile
+++ linux-2.6.31-rc3/mm/Makefile
@@ -41,5 +41,6 @@ endif
obj-$(CONFIG_QUICKLIST) += quicklist.o
obj-$(CONFIG_CGROUP_MEM_RES_CTLR) += memcontrol.o
obj-$(CONFIG_CGROUP_PAGE) += page_cgroup.o
+obj-$(CONFIG_CGROUP_BLKIO) += biotrack.o
obj-$(CONFIG_DEBUG_KMEMLEAK) += kmemleak.o
obj-$(CONFIG_DEBUG_KMEMLEAK_TEST) += kmemleak-test.o
--
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