bwlock-3.6.patch

diff --git a/arch/x86/syscalls/syscall_64.tbl b/arch/x86/syscalls/syscall_64.tbl
index a582bfe..2091eb5 100644
--- a/arch/x86/syscalls/syscall_64.tbl
+++ b/arch/x86/syscalls/syscall_64.tbl
@@ -319,7 +319,7 @@
 310	64	process_vm_readv	sys_process_vm_readv
 311	64	process_vm_writev	sys_process_vm_writev
 312	common	kcmp			sys_kcmp
-
+323	64	bwlock			sys_bwlock
 #
 # x32-specific system call numbers start at 512 to avoid cache impact
 # for native 64-bit operation.
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 23bddac..a2de20b 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1253,6 +1253,10 @@ struct task_struct {
 	struct task_group *sched_task_group;
 #endif
 
+#ifdef CONFIG_BWLOCK
+	int bwlock_val;
+#endif
+
 #ifdef CONFIG_PREEMPT_NOTIFIERS
 	/* list of struct preempt_notifier: */
 	struct hlist_head preempt_notifiers;
diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index 19439c7..bd9efd7 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -860,4 +860,6 @@ asmlinkage long sys_process_vm_writev(pid_t pid,
 
 asmlinkage long sys_kcmp(pid_t pid1, pid_t pid2, int type,
 			 unsigned long idx1, unsigned long idx2);
+
+asmlinkage long sys_bwlock(pid_t pid, int val);
 #endif
diff --git a/init/Kconfig b/init/Kconfig
index af6c7f8..5436bbc 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -848,6 +848,11 @@ config DEBUG_BLK_CGROUP
 
 endif # CGROUPS
 
+config BWLOCK
+	bool "Enable BWLOCK: Memory Bandwidth Lock"
+	help
+	  Enable BWLOCK: Memory Bandwidth Lock (work with MemGuard)
+
 config CHECKPOINT_RESTORE
 	bool "Checkpoint/restore support" if EXPERT
 	default n
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 649c9f8..26260f8 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -1906,10 +1906,20 @@ fire_sched_out_preempt_notifiers(struct task_struct *curr,
  * prepare_task_switch sets up locking and calls architecture specific
  * hooks.
  */
+
+#if CONFIG_BWLOCK
+atomic_t bwlock_core_cnt; 
+EXPORT_SYMBOL(bwlock_core_cnt);
+
 static inline void
 prepare_task_switch(struct rq *rq, struct task_struct *prev,
 		    struct task_struct *next)
 {
+	/* if (prev->bwlock_val > 0 && next->bwlock_val == 0) */
+	/* 	atomic_dec(&bwlock_core_cnt); */
+	/* else if (prev->bwlock_val == 0 && next->bwlock_val > 0) */
+	/* 	atomic_inc(&bwlock_core_cnt); */
+
 	trace_sched_switch(prev, next);
 	sched_info_switch(prev, next);
 	perf_event_task_sched_out(prev, next);
@@ -1918,6 +1928,20 @@ prepare_task_switch(struct rq *rq, struct task_struct *prev,
 	prepare_arch_switch(next);
 }
 
+#else /* !CONFIG_BWLOCK */
+static inline void
+prepare_task_switch(struct rq *rq, struct task_struct *prev,
+		    struct task_struct *next)
+{
+	trace_sched_switch(prev, next);
+	sched_info_switch(prev, next);
+	perf_event_task_sched_out(prev, next);
+	fire_sched_out_preempt_notifiers(prev, next);
+	prepare_lock_switch(rq, next);
+	prepare_arch_switch(next);
+}
+#endif
+
 /**
  * finish_task_switch - clean up after a task-switch
  * @rq: runqueue associated with task-switch
@@ -2092,6 +2116,18 @@ context_switch(struct rq *rq, struct task_struct *prev,
 	finish_task_switch(this_rq(), prev);
 }
 
+
+int nr_bwlocked_cores(void)
+{
+	unsigned long i, sum = 0;
+
+	for_each_online_cpu(i)
+		sum += cpu_rq(i)->curr->bwlock_val;
+	return sum;
+}
+
+EXPORT_SYMBOL(nr_bwlocked_cores);
+
 /*
  * nr_running, nr_uninterruptible and nr_context_switches:
  *
@@ -4451,6 +4487,33 @@ do_sched_setscheduler(pid_t pid, int policy, struct sched_param __user *param)
 	return retval;
 }
 
+
+/**
+ * sys_bwlock - memory bandwidth lock
+ * @pid: pid of the process
+ * @val: bwlock value. 0 - unlock, 1 or bigger - locked
+ */
+SYSCALL_DEFINE2(bwlock, pid_t, pid, int, val)
+{
+	struct task_struct *p;
+	if (pid == 0 || current->pid == pid)
+		p = current;
+	else
+		p = find_process_by_pid(pid);
+
+	if (!p)
+		return -1;
+
+	/* if (val > 0 && p->bwlock_val == 0 && p->state == TASK_RUNNING) */
+	/* 	atomic_inc(&bwlock_core_cnt); */
+	/* else if (val == 0 && p->bwlock_val > 0 && p->state == TASK_RUNNING) */
+	/* 	atomic_dec(&bwlock_core_cnt); */
+
+	p->bwlock_val = val;
+
+	return 0; 
+}
+
 /**
  * sys_sched_setscheduler - set/change the scheduler policy and RT priority
  * @pid: the pid in question.
@@ -7211,6 +7274,10 @@ void __init sched_init(void)
 	int i, j;
 	unsigned long alloc_size = 0, ptr;
 
+#ifdef CONFIG_BWLOCK
+	atomic_set(&bwlock_core_cnt, 0);
+#endif
+
 #ifdef CONFIG_FAIR_GROUP_SCHED
 	alloc_size += 2 * nr_cpu_ids * sizeof(void **);
 #endif