Re: [PATCH v4 1/5] getcpu_cache system call: cache CPU number of running thread

On Tue, 23 Feb 2016, Mathieu Desnoyers wrote:

+/*
+ * If parent process has a thread-local ABI, the child inherits. Only applies
+ * when forking a process, not a thread.
+ */
+void getcpu_cache_fork(struct task_struct *t)
+{
+	t->cpu_cache = current->cpu_cache;
+}
+
+void getcpu_cache_execve(struct task_struct *t)
+{
+	t->cpu_cache = NULL;
+}
+
+void getcpu_cache_exit(struct task_struct *t)
+{
+	t->cpu_cache = NULL;
+}

That's hardly worth a function call. Please inline.

+/*
+ * sys_getcpu_cache - setup getcpu cache for caller thread
+ */
+SYSCALL_DEFINE3(getcpu_cache, int, cmd, int32_t __user * __user *, cpu_cachep,
+		int, flags)
+{
+	if (unlikely(flags))
+		return -EINVAL;

New line for readability sake.

+	switch (cmd) {
+	case GETCPU_CACHE_GET:

Other than that: Reviewed-by: Thomas Gleixner [off-list ref]