[PATCH 4/10] BC: context inheriting and changing

[Kirill Korotaev <dev@openvz.org>]

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

Signed-off-by: Pavel Emelianov <xemul@openvz.org>
Signed-off-by: Kirill Korotaev <dev@openvz.org>

---

 include/bc/task.h     |   51 ++++++++++++++++++++++++++++++++++++
 include/linux/sched.h |    5 +++
 kernel/bc/misc.c      |   70 ++++++++++++++++++++++++++++++++++++++++++++++++++
 kernel/fork.c         |    5 +++
 kernel/irq/handle.c   |    6 ++++
 kernel/softirq.c      |    5 +++
 6 files changed, 142 insertions(+)

--- /dev/null	2006-07-18 14:52:43.075228448 +0400
+++ ./include/bc/task.h	2006-10-05 12:11:44.000000000 +0400
@@ -0,0 +1,51 @@
+/*
+ * include/bc/beancounter.h
+ *
+ * Copyright (C) 2006 OpenVZ SWsoft Inc
+ *
+ */
+
+#ifndef __BC_TASK_H__
+#define __BC_TASK_H__
+
+struct beancounter;
+struct task_struct;
+
+#ifdef CONFIG_BEANCOUNTERS
+#define get_exec_bc()	(current->exec_bc)
+
+#define set_exec_bc(bc)	({			\
+		struct task_struct *t;		\
+		struct beancounter *old;	\
+		t = current;			\
+		old = t->exec_bc;		\
+		t->exec_bc = bc;		\
+		old;				\
+	})
+
+#define reset_exec_bc(old, expected)	do {	\
+		struct task_struct *t;		\
+		t = current;			\
+		BUG_ON(t->exec_bc != expected);\
+		t->exec_bc = old;		\
+	} while (0)
+
+extern struct beancounter init_bc;
+
+void copy_beancounter(struct task_struct *tsk, struct task_struct *parent);
+void free_beancounter(struct task_struct *tsk);
+int bc_task_move(struct task_struct *tsk, struct beancounter *bc);
+#else
+static inline void copy_beancounter(struct task_struct *tsk,
+		struct task_struct *parent)
+{
+}
+
+static inline void free_beancounter(struct task_struct *tsk)
+{
+}
+
+#define set_exec_bc(bc)		(NULL)
+#define reset_exec_bc(bc, exp)	do { } while (0)
+#endif
+#endif
--- ./include/linux/sched.h.bc_task	2006-10-05 11:42:43.000000000 +0400
+++ ./include/linux/sched.h	2006-10-05 12:11:44.000000000 +0400
@@ -77,6 +77,8 @@ struct sched_param {
 #include <linux/futex.h>
 #include <linux/rtmutex.h>
 
+#include <bc/task.h>
+
 #include <linux/time.h>
 #include <linux/param.h>
 #include <linux/resource.h>
@@ -1055,6 +1057,9 @@ struct task_struct {
 #ifdef	CONFIG_TASK_DELAY_ACCT
 	struct task_delay_info *delays;
 #endif
+#ifdef CONFIG_BEANCOUNTERS
+	struct beancounter *exec_bc;
+#endif
 };
 
 static inline pid_t process_group(struct task_struct *tsk)
--- /dev/null	2006-07-18 14:52:43.075228448 +0400
+++ ./kernel/bc/misc.c	2006-10-05 12:11:44.000000000 +0400
@@ -0,0 +1,70 @@
+/*
+ * kernel/bc/misc.c
+ *
+ * Copyright (C) 2006 OpenVZ SWsoft Inc
+ *
+ */
+
+#include <linux/sched.h>
+#include <linux/stop_machine.h>
+
+#include <bc/beancounter.h>
+#include <bc/task.h>
+
+void copy_beancounter(struct task_struct *tsk, struct task_struct *parent)
+{
+	tsk->exec_bc = bc_get(parent->exec_bc);
+}
+
+void free_beancounter(struct task_struct *tsk)
+{
+	bc_put(tsk->exec_bc);
+	tsk->exec_bc = NULL;
+}
+
+struct set_bcid_data {
+	struct beancounter *bc;
+	struct mm_struct *mm;
+};
+
+static int do_set_bcid(void *data)
+{
+	struct set_bcid_data *d;
+	struct mm_struct *mm;
+	struct task_struct *g, *p;
+
+	d = (struct set_bcid_data *)data;
+	mm = d->mm;
+
+	do_each_thread (g, p) {
+		if (p->mm == mm) {
+			bc_put(p->exec_bc);
+			p->exec_bc = bc_get(d->bc);
+		}
+	} while_each_thread (g, p);
+
+	bc_put(mm->mm_bc);
+	mm->mm_bc = bc_get(d->bc);
+	return 0;
+}
+
+int bc_task_move(struct task_struct *tsk, struct beancounter *bc)
+{
+	int err;
+	struct set_bcid_data data;
+	struct mm_struct *mm;
+
+	mm = get_task_mm(tsk);
+	if (mm == NULL)
+		return -EINVAL;
+
+	data.bc = bc;
+	data.mm = mm;
+
+	down_write(&mm->mmap_sem);
+	err = stop_machine_run(do_set_bcid, &data, NR_CPUS);
+	up_write(&mm->mmap_sem);
+
+	mmput(mm);
+	return err;
+}
--- ./kernel/fork.c.bc_task	2006-10-05 11:42:43.000000000 +0400
+++ ./kernel/fork.c	2006-10-05 12:11:44.000000000 +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>
@@ -105,6 +107,7 @@ static kmem_cache_t *mm_cachep;
 
 void free_task(struct task_struct *tsk)
 {
+	free_beancounter(tsk);
 	free_thread_info(tsk->thread_info);
 	rt_mutex_debug_task_free(tsk);
 	free_task_struct(tsk);
@@ -984,6 +987,8 @@ static struct task_struct *copy_process(
 	if (!p)
 		goto fork_out;
 
+	copy_beancounter(p, current);
+
 #ifdef CONFIG_TRACE_IRQFLAGS
 	DEBUG_LOCKS_WARN_ON(!p->hardirqs_enabled);
 	DEBUG_LOCKS_WARN_ON(!p->softirqs_enabled);
--- ./kernel/irq/handle.c.bc_task	2006-10-05 11:42:43.000000000 +0400
+++ ./kernel/irq/handle.c	2006-10-05 12:11:44.000000000 +0400
@@ -16,6 +16,8 @@
 #include <linux/interrupt.h>
 #include <linux/kernel_stat.h>
 
+#include <bc/task.h>
+
 #include "internals.h"
 
 /**
@@ -172,6 +174,7 @@ fastcall unsigned int __do_IRQ(unsigned 
 	struct irq_desc *desc = irq_desc + irq;
 	struct irqaction *action;
 	unsigned int status;
+	struct beancounter *bc;
 
 	kstat_this_cpu.irqs[irq]++;
 	if (CHECK_IRQ_PER_CPU(desc->status)) {
@@ -228,6 +231,8 @@ fastcall unsigned int __do_IRQ(unsigned 
 	 * useful for irq hardware that does not mask cleanly in an
 	 * SMP environment.
 	 */
+
+	bc = set_exec_bc(&init_bc);
 	for (;;) {
 		irqreturn_t action_ret;
 
@@ -242,6 +247,7 @@ fastcall unsigned int __do_IRQ(unsigned 
 			break;
 		desc->status &= ~IRQ_PENDING;
 	}
+	reset_exec_bc(bc, &init_bc);
 	desc->status &= ~IRQ_INPROGRESS;
 
 out:
--- ./kernel/softirq.c.bc_task	2006-10-05 11:42:43.000000000 +0400
+++ ./kernel/softirq.c	2006-10-05 12:11:44.000000000 +0400
@@ -18,6 +18,8 @@
 #include <linux/rcupdate.h>
 #include <linux/smp.h>
 
+#include <bc/task.h>
+
 #include <asm/irq.h>
 /*
    - No shared variables, all the data are CPU local.
@@ -209,6 +211,7 @@ asmlinkage void __do_softirq(void)
 	__u32 pending;
 	int max_restart = MAX_SOFTIRQ_RESTART;
 	int cpu;
+	struct beancounter *bc;
 
 	pending = local_softirq_pending();
 	account_system_vtime(current);
@@ -225,6 +228,7 @@ restart:
 
 	h = softirq_vec;
 
+	bc = set_exec_bc(&init_bc);
 	do {
 		if (pending & 1) {
 			h->action(h);
@@ -233,6 +237,7 @@ restart:
 		h++;
 		pending >>= 1;
 	} while (pending);
+	reset_exec_bc(bc, &init_bc);
 
 	local_irq_disable();