[RFC][PATCH 3/7] UBC: ub context and inheritance

[Kirill Korotaev <dev@sw.ru>]

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

Task references three beancounters:
  1. exec_ub  current context. all resources are
              charged to this beancounter.
  2. task_ub  beancounter to which task_struct is
              charged itself.
  3. fork_sub 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/linux/sched.h   |    5 +++++
 include/ub/task.h       |   42 ++++++++++++++++++++++++++++++++++++++++++
 kernel/fork.c           |   21 ++++++++++++++++-----
 kernel/irq/handle.c     |    9 +++++++++
 kernel/softirq.c        |    8 ++++++++
 kernel/ub/Makefile      |    1 +
 kernel/ub/beancounter.c |    4 ++++
 kernel/ub/misc.c        |   34 ++++++++++++++++++++++++++++++++++
 8 files changed, 119 insertions(+), 5 deletions(-)

--- ./include/linux/sched.h.ubfork	2006-07-17 17:01:12.000000000 +0400
+++ ./include/linux/sched.h	2006-07-31 16:01:54.000000000 +0400
@@ -81,6 +81,8 @@ struct sched_param {
 #include <linux/timer.h>
 #include <linux/hrtimer.h>
 
+#include <ub/task.h>
+
 #include <asm/processor.h>
 
 struct exec_domain;
@@ -997,6 +999,9 @@ struct task_struct {
 	spinlock_t delays_lock;
 	struct task_delay_info *delays;
 #endif
+#ifdef CONFIG_USER_RESOURCE
+	struct task_beancounter	task_bc;
+#endif
 };
 
 static inline pid_t process_group(struct task_struct *tsk)
--- ./include/ub/task.h.ubfork	2006-07-28 18:53:52.000000000 +0400
+++ ./include/ub/task.h	2006-08-01 15:26:08.000000000 +0400
@@ -0,0 +1,42 @@
+/*
+ *  include/ub/task.h
+ *
+ *  Copyright (C) 2006 OpenVZ. SWsoft Inc
+ *
+ */
+
+#ifndef __UB_TASK_H_
+#define __UB_TASK_H_
+
+#include <linux/config.h>
+
+struct user_beancounter;
+
+struct task_beancounter {
+	struct user_beancounter *exec_ub;
+	struct user_beancounter *task_ub;
+	struct user_beancounter *fork_sub;
+};
+
+#ifdef CONFIG_USER_RESOURCE
+#define get_exec_ub()		(current->task_bc.exec_ub)
+#define set_exec_ub(newub)			\
+	({					\
+		 struct user_beancounter *old;	\
+		 struct task_beancounter *tbc;	\
+		 tbc = &current->task_bc;	\
+		 old = tbc->exec_ub;		\
+		 tbc->exec_ub = newub;		\
+		 old;				\
+	 })
+
+int ub_task_charge(struct task_struct *parent, struct task_struct *new);
+void ub_task_uncharge(struct task_struct *tsk);
+
+#else /* CONFIG_USER_RESOURCE */
+#define get_exec_ub()		(NULL)
+#define set_exec_ub(__ub)	(NULL)
+#define ub_task_charge(p, t)	(0)
+#define ub_task_uncharge(t)	do { } while (0)
+#endif /* CONFIG_USER_RESOURCE */
+#endif /* __UB_TASK_H_ */
--- ./kernel/irq/handle.c.ubirq	2006-07-10 12:39:20.000000000 +0400
+++ ./kernel/irq/handle.c	2006-08-01 12:39:34.000000000 +0400
@@ -16,6 +16,9 @@
 #include <linux/interrupt.h>
 #include <linux/kernel_stat.h>
 
+#include <ub/beancounter.h>
+#include <ub/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 user_beancounter *ub;
+
+	ub = set_exec_ub(&ub0);
 
 	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);
+
+		(void) set_exec_ub(ub);
 		return 1;
 	}
 
@@ -246,6 +254,7 @@ out:
 	desc->chip->end(irq);
 	spin_unlock(&desc->lock);
 
+	(void) set_exec_ub(ub);
 	return 1;
 }
 
--- ./kernel/softirq.c.ubirq	2006-07-17 17:01:12.000000000 +0400
+++ ./kernel/softirq.c	2006-08-01 12:40:44.000000000 +0400
@@ -18,6 +18,9 @@
 #include <linux/rcupdate.h>
 #include <linux/smp.h>
 
+#include <ub/beancounter.h>
+#include <ub/task.h>
+
 #include <asm/irq.h>
 /*
    - No shared variables, all the data are CPU local.
@@ -191,6 +194,9 @@ asmlinkage void __do_softirq(void)
 	__u32 pending;
 	int max_restart = MAX_SOFTIRQ_RESTART;
 	int cpu;
+	struct user_beancounter *ub;
+
+	ub = set_exec_ub(&ub0);
 
 	pending = local_softirq_pending();
 	account_system_vtime(current);
@@ -229,6 +235,8 @@ restart:
 
 	account_system_vtime(current);
 	_local_bh_enable();
+
+	(void) set_exec_ub(ub);
 }
 
 #ifndef __ARCH_HAS_DO_SOFTIRQ
--- ./kernel/fork.c.ubfork	2006-07-17 17:01:12.000000000 +0400
+++ ./kernel/fork.c	2006-08-01 12:58:36.000000000 +0400
@@ -46,6 +46,8 @@
 #include <linux/delayacct.h>
 #include <linux/taskstats_kern.h>
 
+#include <ub/task.h>
+
 #include <asm/pgtable.h>
 #include <asm/pgalloc.h>
 #include <asm/uaccess.h>
@@ -102,6 +104,7 @@ static kmem_cache_t *mm_cachep;
 
 void free_task(struct task_struct *tsk)
 {
+	ub_task_uncharge(tsk);
 	free_thread_info(tsk->thread_info);
 	rt_mutex_debug_task_free(tsk);
 	free_task_struct(tsk);
@@ -162,18 +165,19 @@ static struct task_struct *dup_task_stru
 
 	tsk = alloc_task_struct();
 	if (!tsk)
-		return NULL;
+		goto out;
 
 	ti = alloc_thread_info(tsk);
-	if (!ti) {
-		free_task_struct(tsk);
-		return NULL;
-	}
+	if (!ti)
+		goto out_tsk;
 
 	*tsk = *orig;
 	tsk->thread_info = ti;
 	setup_thread_stack(tsk, orig);
 
+	if (ub_task_charge(orig, tsk))
+		goto out_ti;
+
 	/* One for us, one for whoever does the "release_task()" (usually parent) */
 	atomic_set(&tsk->usage,2);
 	atomic_set(&tsk->fs_excl, 0);
@@ -180,6 +184,13 @@ static struct task_struct *dup_task_stru
 #endif
 	tsk->splice_pipe = NULL;
 	return tsk;
+
+out_ti:
+	free_thread_info(ti);
+out_tsk:
+	free_task_struct(tsk);
+out:
+	return NULL;
 }
 
 #ifdef CONFIG_MMU
--- ./kernel/ub/Makefile.ubcore	2006-08-03 16:24:56.000000000 +0400
+++ ./kernel/ub/Makefile	2006-08-01 11:08:39.000000000 +0400
@@ -5,3 +5,4 @@
 #
 
 obj-$(CONFIG_USER_RESOURCE) += beancounter.o
+obj-$(CONFIG_USER_RESOURCE) += misc.o
--- ./kernel/ub/beancounter.c.ubcore	2006-07-28 13:07:44.000000000 +0400
+++ ./kernel/ub/beancounter.c	2006-08-03 16:14:17.000000000 +0400
@@ -395,6 +395,10 @@
 	spin_lock_init(&ub_hash_lock);
 	slot = &ub_hash[ub_hash_fun(ub->ub_uid)];
 	hlist_add_head(&ub->hash, slot);
+
+	current->task_bc.exec_ub = ub;
+	current->task_bc.task_ub = get_beancounter(ub);
+	current->task_bc.fork_sub = get_beancounter(ub);
 }
 
 void __init ub_init_late(void)
--- ./kernel/ub/misc.c.ubfork	2006-07-31 16:23:44.000000000 +0400
+++ ./kernel/ub/misc.c	2006-07-31 16:28:47.000000000 +0400
@@ -0,0 +1,34 @@
+/*
+ * kernel/ub/misc.c
+ *
+ * Copyright (C) 2006 OpenVZ. SWsoft Inc.
+ *
+ */
+
+#include <linux/sched.h>
+
+#include <ub/beancounter.h>
+#include <ub/task.h>
+
+int ub_task_charge(struct task_struct *parent, struct task_struct *new)
+{
+	struct task_beancounter *old_bc;
+	struct task_beancounter *new_bc;
+	struct user_beancounter *ub;
+
+	old_bc = &parent->task_bc;
+	new_bc = &new->task_bc;
+
+	ub = old_bc->fork_sub;
+	new_bc->exec_ub = get_beancounter(ub);
+	new_bc->task_ub = get_beancounter(ub);
+	new_bc->fork_sub = get_beancounter(ub);
+	return 0;
+}
+
+void ub_task_uncharge(struct task_struct *tsk)
+{
+	put_beancounter(tsk->task_bc.exec_ub);
+	put_beancounter(tsk->task_bc.task_ub);
+	put_beancounter(tsk->task_bc.fork_sub);
+}