sched: Add snapshot of affinity changes

This snapshot is taken from msm-4.19 as of 'commit 5debecbe7195
("trace: filter out spurious preemption and IRQs disable traces")'.

Change-Id: I5b7bcbbc1da5dffb89932dfda392029159d17859
Signed-off-by: Satya Durga Srinivasu Prabhala <satyap@codeaurora.org>

drivers/cpufreq/cpufreq.c

@@ -29,6 +29,7 @@
 #include <linux/suspend.h>
 #include <linux/syscore_ops.h>
 #include <linux/tick.h>
+#include <linux/sched/sysctl.h>
 #include <trace/events/power.h>
 
 static LIST_HEAD(cpufreq_policy_list);
@@ -688,11 +689,35 @@ static ssize_t show_##file_name				\
 }
 
 show_one(cpuinfo_min_freq, cpuinfo.min_freq);
-show_one(cpuinfo_max_freq, cpuinfo.max_freq);
 show_one(cpuinfo_transition_latency, cpuinfo.transition_latency);
 show_one(scaling_min_freq, min);
 show_one(scaling_max_freq, max);
 
+unsigned int cpuinfo_max_freq_cached;
+
+static bool should_use_cached_freq(int cpu)
+{
+	if (!cpuinfo_max_freq_cached)
+		return false;
+
+	if (!(BIT(cpu) & sched_lib_mask_force))
+		return false;
+
+	return is_sched_lib_based_app(current->pid);
+}
+
+static ssize_t show_cpuinfo_max_freq(struct cpufreq_policy *policy, char *buf)
+{
+	unsigned int freq = policy->cpuinfo.max_freq;
+
+	if (should_use_cached_freq(policy->cpu))
+		freq = cpuinfo_max_freq_cached << 1;
+	else
+		freq = policy->cpuinfo.max_freq;
+
+	return scnprintf(buf, PAGE_SIZE, "%u\n", freq);
+}
+
 __weak unsigned int arch_freq_get_on_cpu(int cpu)
 {
 	return 0;

drivers/cpufreq/freq_table.c

@@ -54,6 +54,9 @@ int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy,
 	policy->min = policy->cpuinfo.min_freq = min_freq;
 	policy->max = policy->cpuinfo.max_freq = max_freq;
 
+	if (max_freq > cpuinfo_max_freq_cached)
+		cpuinfo_max_freq_cached = max_freq;
+
 	if (policy->min == ~0)
 		return -EINVAL;
 	else

include/linux/cpufreq.h

@@ -1000,4 +1000,6 @@ unsigned int cpufreq_generic_get(unsigned int cpu);
 void cpufreq_generic_init(struct cpufreq_policy *policy,
 		struct cpufreq_frequency_table *table,
 		unsigned int transition_latency);
+
+extern unsigned int cpuinfo_max_freq_cached;
 #endif /* _LINUX_CPUFREQ_H */

include/linux/sched/sysctl.h

@@ -101,4 +101,9 @@ extern int sched_energy_aware_handler(struct ctl_table *table, int write,
 				 loff_t *ppos);
 #endif
 
+#define LIB_PATH_LENGTH 512
+extern char sched_lib_name[LIB_PATH_LENGTH];
+extern unsigned int sched_lib_mask_force;
+extern bool is_sched_lib_based_app(pid_t pid);
+
 #endif /* _LINUX_SCHED_SYSCTL_H */

kernel/sched/core.c

@@ -5474,6 +5474,60 @@ out_put_task:
 	return retval;
 }
 
+char sched_lib_name[LIB_PATH_LENGTH];
+unsigned int sched_lib_mask_force;
+bool is_sched_lib_based_app(pid_t pid)
+{
+	const char *name = NULL;
+	struct vm_area_struct *vma;
+	char path_buf[LIB_PATH_LENGTH];
+	bool found = false;
+	struct task_struct *p;
+	struct mm_struct *mm;
+
+	if (strnlen(sched_lib_name, LIB_PATH_LENGTH) == 0)
+		return false;
+
+	rcu_read_lock();
+
+	p = find_process_by_pid(pid);
+	if (!p) {
+		rcu_read_unlock();
+		return false;
+	}
+
+	/* Prevent p going away */
+	get_task_struct(p);
+	rcu_read_unlock();
+
+	mm = get_task_mm(p);
+	if (!mm)
+		goto put_task_struct;
+
+	down_read(&mm->mmap_sem);
+	for (vma = mm->mmap; vma ; vma = vma->vm_next) {
+		if (vma->vm_file && vma->vm_flags & VM_EXEC) {
+			name = d_path(&vma->vm_file->f_path,
+					path_buf, LIB_PATH_LENGTH);
+			if (IS_ERR(name))
+				goto release_sem;
+
+			if (strnstr(name, sched_lib_name,
+					strnlen(name, LIB_PATH_LENGTH))) {
+				found = true;
+				break;
+			}
+		}
+	}
+
+release_sem:
+	up_read(&mm->mmap_sem);
+	mmput(mm);
+put_task_struct:
+	put_task_struct(p);
+	return found;
+}
+
 static int get_user_cpu_mask(unsigned long __user *user_mask_ptr, unsigned len,
 			     struct cpumask *new_mask)
 {

kernel/sysctl.c

@@ -139,6 +139,9 @@ static int ten_thousand = 10000;
 #ifdef CONFIG_PERF_EVENTS
 static int six_hundred_forty_kb = 640 * 1024;
 #endif
+#ifdef CONFIG_SCHED_WALT
+static int two_hundred_fifty_five = 255;
+#endif
 
 /* this is needed for the proc_doulongvec_minmax of vm_dirty_bytes */
 static unsigned long dirty_bytes_min = 2 * PAGE_SIZE;
@@ -499,6 +502,24 @@ static struct ctl_table kern_table[] = {
 		.extra2		= SYSCTL_ONE,
 	},
 #endif
+#ifdef CONFIG_SCHED_WALT
+	{
+		.procname	= "sched_lib_name",
+		.data		= sched_lib_name,
+		.maxlen		= LIB_PATH_LENGTH,
+		.mode		= 0644,
+		.proc_handler	= proc_dostring,
+	},
+	{
+		.procname	= "sched_lib_mask_force",
+		.data		= &sched_lib_mask_force,
+		.maxlen		= sizeof(unsigned int),
+		.mode		= 0644,
+		.proc_handler	= proc_douintvec_minmax,
+		.extra1		= SYSCTL_ZERO,
+		.extra2		= &two_hundred_fifty_five,
+	},
+#endif
 #ifdef CONFIG_PROVE_LOCKING
 	{
 		.procname	= "prove_locking",