[PATCH 4/7] BC: context inheriting and changing

[Kirill Korotaev <dev@sw.ru>]

Contains code responsible for setting BC on task,
it's inheriting and setting host context in interrupts.

Task references 2 beancounters:
1. exec_bc: current context. all resources are
            charged to this beancounter.
3. fork_bc: beancounter which is inherited by
            task's children on fork

Signed-off-by: Pavel Emelianov <xemul@sw.ru>
Signed-off-by: Kirill Korotaev <dev@sw.ru>

---

 include/bc/task.h       |   59 ++++++++++++++++++++++++++++++++++++++++++++++++
 include/linux/sched.h   |    5 ++++
 kernel/bc/Makefile      |    1 
 kernel/bc/beancounter.c |    3 ++
 kernel/bc/misc.c        |   32 ++++++++++++++++++++++++++
 kernel/fork.c           |   17 ++++++++++++-
 kernel/irq/handle.c     |    9 +++++++
 kernel/softirq.c        |    8 ++++++
 8 files changed, 132 insertions(+), 2 deletions(-)

--- /dev/null	2006-07-18 14:52:43.075228448 +0400
+++ ./include/bc/task.h	2006-08-28 12:54:48.000000000 +0400
@@ -0,0 +1,59 @@
+/*
+ *  include/bc/task.h
+ *
+ *  Copyright (C) 2006 OpenVZ. SWsoft Inc
+ *
+ */
+
+#ifndef __BC_TASK_H_
+#define __BC_TASK_H_
+
+struct beancounter;
+
+struct task_beancounter {
+	struct beancounter *exec_bc;
+	struct beancounter *fork_bc;
+};
+
+#ifdef CONFIG_BEANCOUNTERS
+
+#define get_exec_bc()		(current->task_bc.exec_bc)
+#define set_exec_bc(new)			\
+	({					\
+		 struct beancounter *old;	\
+		 struct task_beancounter *tbc;	\
+		 tbc = &current->task_bc;	\
+		 old = tbc->exec_bc;		\
+		 tbc->exec_bc = new;		\
+		 old;				\
+	 })
+#define reset_exec_bc(old, exp)			\
+	do {					\
+		struct task_beancounter *tbc;	\
+		tbc = &current->task_bc;	\
+		BUG_ON(tbc->exec_bc != exp);	\
+		tbc->exec_bc = old;		\
+	} while (0)
+
+int __must_check bc_task_charge(struct task_struct *parent,
+		struct task_struct *new);
+void bc_task_uncharge(struct task_struct *tsk);
+
+#else
+
+#define get_exec_bc()		(NULL)
+#define set_exec_bc(new)	(NULL)
+#define reset_exec_bc(new, exp)	do { } while (0)
+
+static inline __must_check int bc_task_charge(struct task_struct *parent,
+		struct task_struct *new)
+{
+	return 0;
+}
+
+static inline void bc_task_uncharge(struct task_struct *tsk)
+{
+}
+
+#endif
+#endif
--- ./include/linux/sched.h.bctask	2006-08-28 12:20:13.000000000 +0400
+++ ./include/linux/sched.h	2006-08-28 12:52:11.000000000 +0400
@@ -83,6 +83,8 @@ struct sched_param {
 #include <linux/timer.h>
 #include <linux/hrtimer.h>
 
+#include <bc/task.h>
+
 #include <asm/processor.h>
 
 struct exec_domain;
@@ -1048,6 +1050,9 @@ struct task_struct {
 	spinlock_t delays_lock;
 	struct task_delay_info *delays;
 #endif
+#ifdef CONFIG_BEANCOUNTERS
+	struct task_beancounter	task_bc;
+#endif
 };
 
 static inline pid_t process_group(struct task_struct *tsk)
--- ./kernel/bc/Makefile.bctask	2006-08-28 12:43:34.000000000 +0400
+++ ./kernel/bc/Makefile	2006-08-28 12:52:11.000000000 +0400
@@ -5,3 +5,4 @@
 #
 
 obj-$(CONFIG_BEANCOUNTERS) += beancounter.o
+obj-$(CONFIG_BEANCOUNTERS) += misc.o
--- ./kernel/bc/beancounter.c.bctask	2006-08-28 12:49:07.000000000 +0400
+++ ./kernel/bc/beancounter.c	2006-08-28 12:52:11.000000000 +0400
@@ -238,6 +238,9 @@ void __init bc_init_early(void)
 	spin_lock_init(&bc_hash_lock);
 	slot = &bc_hash[bc_hash_fn(bc->bc_id)];
 	hlist_add_head(&bc->hash, slot);
+
+	current->task_bc.exec_bc = get_beancounter(bc);
+	current->task_bc.fork_bc = get_beancounter(bc);
 }
 
 void __init bc_init_late(void)
--- /dev/null	2006-07-18 14:52:43.075228448 +0400
+++ ./kernel/bc/misc.c	2006-08-28 12:52:11.000000000 +0400
@@ -0,0 +1,32 @@
+/*
+ * kernel/bc/misc.c
+ *
+ * Copyright (C) 2006 OpenVZ. SWsoft Inc.
+ *
+ */
+
+#include <linux/sched.h>
+
+#include <bc/beancounter.h>
+#include <bc/task.h>
+
+int bc_task_charge(struct task_struct *parent, struct task_struct *new)
+{
+	struct task_beancounter *old_bc;
+	struct task_beancounter *new_bc;
+	struct beancounter *bc;
+
+	old_bc = &parent->task_bc;
+	new_bc = &new->task_bc;
+
+	bc = old_bc->fork_bc;
+	new_bc->exec_bc = get_beancounter(bc);
+	new_bc->fork_bc = get_beancounter(bc);
+	return 0;
+}
+
+void bc_task_uncharge(struct task_struct *tsk)
+{
+	put_beancounter(tsk->task_bc.exec_bc);
+	put_beancounter(tsk->task_bc.fork_bc);
+}
--- ./kernel/fork.c.bctask	2006-08-28 12:20:13.000000000 +0400
+++ ./kernel/fork.c	2006-08-28 12:52:11.000000000 +0400
@@ -49,6 +49,8 @@
 #include <linux/taskstats_kern.h>
 #include <linux/random.h>
 
+#include <bc/task.h>
+
 #include <asm/pgtable.h>
 #include <asm/pgalloc.h>
 #include <asm/uaccess.h>
@@ -103,12 +105,18 @@ kmem_cache_t *vm_area_cachep;
 /* SLAB cache for mm_struct structures (tsk->mm) */
 static kmem_cache_t *mm_cachep;
 
-void free_task(struct task_struct *tsk)
+static void __free_task(struct task_struct *tsk)
 {
 	free_thread_info(tsk->thread_info);
 	rt_mutex_debug_task_free(tsk);
 	free_task_struct(tsk);
 }
+
+void free_task(struct task_struct *tsk)
+{
+	bc_task_uncharge(tsk);
+	__free_task(tsk);
+}
 EXPORT_SYMBOL(free_task);
 
 void __put_task_struct(struct task_struct *tsk)
@@ -983,6 +991,9 @@ static struct task_struct *copy_process(
 	if (!p)
 		goto fork_out;
 
+	if (bc_task_charge(current, p))
+		goto bad_charge;
+
 #ifdef CONFIG_TRACE_IRQFLAGS
 	DEBUG_LOCKS_WARN_ON(!p->hardirqs_enabled);
 	DEBUG_LOCKS_WARN_ON(!p->softirqs_enabled);
@@ -1293,7 +1304,9 @@ bad_fork_cleanup_count:
 	atomic_dec(&p->user->processes);
 	free_uid(p->user);
 bad_fork_free:
-	free_task(p);
+	bc_task_uncharge(p);
+bad_charge:
+	__free_task(p);
 fork_out:
 	return ERR_PTR(retval);
 }
--- ./kernel/irq/handle.c.bctask	2006-07-10 12:39:20.000000000 +0400
+++ ./kernel/irq/handle.c	2006-08-28 12:52:11.000000000 +0400
@@ -16,6 +16,9 @@
 #include <linux/interrupt.h>
 #include <linux/kernel_stat.h>
 
+#include <bc/beancounter.h>
+#include <bc/task.h>
+
 #include "internals.h"
 
 /**
@@ -166,6 +169,9 @@ fastcall unsigned int __do_IRQ(unsigned 
 	struct irq_desc *desc = irq_desc + irq;
 	struct irqaction *action;
 	unsigned int status;
+	struct beancounter *bc;
+
+	bc = set_exec_bc(&init_bc);
 
 	kstat_this_cpu.irqs[irq]++;
 	if (CHECK_IRQ_PER_CPU(desc->status)) {
@@ -178,6 +184,8 @@ fastcall unsigned int __do_IRQ(unsigned 
 			desc->chip->ack(irq);
 		action_ret = handle_IRQ_event(irq, regs, desc->action);
 		desc->chip->end(irq);
+
+		reset_exec_bc(bc, &init_bc);
 		return 1;
 	}
 
@@ -246,6 +254,7 @@ out:
 	desc->chip->end(irq);
 	spin_unlock(&desc->lock);
 
+	reset_exec_bc(bc, &init_bc);
 	return 1;
 }
 
--- ./kernel/softirq.c.bctask	2006-08-28 12:20:13.000000000 +0400
+++ ./kernel/softirq.c	2006-08-28 12:52:11.000000000 +0400
@@ -18,6 +18,9 @@
 #include <linux/rcupdate.h>
 #include <linux/smp.h>
 
+#include <bc/beancounter.h>
+#include <bc/task.h>
+
 #include <asm/irq.h>
 /*
    - No shared variables, all the data are CPU local.
@@ -209,6 +212,9 @@ asmlinkage void __do_softirq(void)
 	__u32 pending;
 	int max_restart = MAX_SOFTIRQ_RESTART;
 	int cpu;
+	struct beancounter *bc;
+
+	bc = set_exec_bc(&init_bc);
 
 	pending = local_softirq_pending();
 	account_system_vtime(current);
@@ -247,6 +253,8 @@ restart:
 
 	account_system_vtime(current);
 	_local_bh_enable();
+
+	reset_exec_bc(bc, &init_bc);
 }
 
 #ifndef __ARCH_HAS_DO_SOFTIRQ