[PATCH v2 26/33] Task fork and exit for rdtgroup

[Fenghua Yu]

From: Fenghua Yu <fenghua.yu@xxxxxxxxx>

When a task is forked, it inherites its parent rdtgroup. The task
can be moved to other rdtgroup during its run time.

When the task exits, it's deleted from it's current rdtgroup's task
list.

Signed-off-by: Fenghua Yu <fenghua.yu@xxxxxxxxx>
Reviewed-by: Tony Luck <tony.luck@xxxxxxxxx>
---
 arch/x86/kernel/cpu/intel_rdt_rdtgroup.c | 22 ++++++++++++++++++++++
 kernel/exit.c                            |  2 ++
 kernel/fork.c                            |  2 ++
 3 files changed, 26 insertions(+)

diff --git a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
index 7842194..acea62c 100644
--- a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
+++ b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
@@ -956,3 +956,25 @@ int __init rdtgroup_init(void)
 
 	return 0;
 }
+
+void rdtgroup_fork(struct task_struct *child)
+{
+	struct rdtgroup *rdtgrp;
+
+	INIT_LIST_HEAD(&child->rg_list);
+	if (!rdtgroup_mounted)
+		return;
+
+	mutex_lock(&rdtgroup_mutex);
+
+	rdtgrp = current->rdtgroup;
+	if (!rdtgrp)
+		goto out;
+
+	list_add_tail(&child->rg_list, &rdtgrp->pset.tasks);
+	child->rdtgroup = rdtgrp;
+	atomic_inc(&rdtgrp->refcount);
+
+out:
+	mutex_unlock(&rdtgroup_mutex);
+}
diff --git a/kernel/exit.c b/kernel/exit.c
index 091a78b..270ede6 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -54,6 +54,7 @@
 #include <linux/writeback.h>
 #include <linux/shm.h>
 #include <linux/kcov.h>
+#include <linux/resctrl.h>
 
 #include <asm/uaccess.h>
 #include <asm/unistd.h>
@@ -837,6 +838,7 @@ void do_exit(long code)
 	perf_event_exit_task(tsk);
 
 	cgroup_exit(tsk);
+	rdtgroup_exit(tsk);
 
 	/*
 	 * FIXME: do that only when needed, using sched_exit tracepoint
diff --git a/kernel/fork.c b/kernel/fork.c
index beb3172..79bfc99 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -76,6 +76,7 @@
 #include <linux/compiler.h>
 #include <linux/sysctl.h>
 #include <linux/kcov.h>
+#include <linux/resctrl.h>
 
 #include <asm/pgtable.h>
 #include <asm/pgalloc.h>
@@ -1426,6 +1427,7 @@ static struct task_struct *copy_process(unsigned long clone_flags,
 	p->io_context = NULL;
 	p->audit_context = NULL;
 	cgroup_fork(p);
+	rdtgroup_fork(p);
 #ifdef CONFIG_NUMA
 	p->mempolicy = mpol_dup(p->mempolicy);
 	if (IS_ERR(p->mempolicy)) {
-- 
2.5.0