Revert "sched/psi: Fix avgs_work re-arm in psi_avgs_work()"

This reverts commit 7d8bba4da1 which is
commit 2fcd7bbae90a6d844da8660a9d27079281dfbba2 upstream.

It is part of a patch series that breaks the Android API.  If this
series is needed in Android devices in the future, it can come back in
an ABI-safe manner.

Bug: 161946584
Change-Id: I6737a0ee4a39082058be5a63caee994af70a262e
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
This commit is contained in:
Greg Kroah-Hartman 2023-09-07 10:48:39 +00:00
parent d18fe3efda
commit 469cf75fcc
2 changed files with 3 additions and 30 deletions

View File

@ -72,9 +72,6 @@ enum psi_states {
/* Use one bit in the state mask to track TSK_ONCPU */
#define PSI_ONCPU (1 << NR_PSI_STATES)
/* Flag whether to re-arm avgs_work, see details in get_recent_times() */
#define PSI_STATE_RESCHEDULE (1 << (NR_PSI_STATES + 1))
enum psi_aggregators {
PSI_AVGS = 0,
PSI_POLL,

View File

@ -243,8 +243,6 @@ static void get_recent_times(struct psi_group *group, int cpu,
u32 *pchanged_states)
{
struct psi_group_cpu *groupc = per_cpu_ptr(group->pcpu, cpu);
int current_cpu = raw_smp_processor_id();
unsigned int tasks[NR_PSI_TASK_COUNTS];
u64 now, state_start;
enum psi_states s;
unsigned int seq;
@ -259,8 +257,6 @@ static void get_recent_times(struct psi_group *group, int cpu,
memcpy(times, groupc->times, sizeof(groupc->times));
state_mask = groupc->state_mask;
state_start = groupc->state_start;
if (cpu == current_cpu)
memcpy(tasks, groupc->tasks, sizeof(groupc->tasks));
} while (read_seqcount_retry(&groupc->seq, seq));
/* Calculate state time deltas against the previous snapshot */
@ -285,28 +281,6 @@ static void get_recent_times(struct psi_group *group, int cpu,
if (delta)
*pchanged_states |= (1 << s);
}
/*
* When collect_percpu_times() from the avgs_work, we don't want to
* re-arm avgs_work when all CPUs are IDLE. But the current CPU running
* this avgs_work is never IDLE, cause avgs_work can't be shut off.
* So for the current CPU, we need to re-arm avgs_work only when
* (NR_RUNNING > 1 || NR_IOWAIT > 0 || NR_MEMSTALL > 0), for other CPUs
* we can just check PSI_NONIDLE delta.
*/
if (current_work() == &group->avgs_work.work) {
bool reschedule;
if (cpu == current_cpu)
reschedule = tasks[NR_RUNNING] +
tasks[NR_IOWAIT] +
tasks[NR_MEMSTALL] > 1;
else
reschedule = *pchanged_states & (1 << PSI_NONIDLE);
if (reschedule)
*pchanged_states |= PSI_STATE_RESCHEDULE;
}
}
static void calc_avgs(unsigned long avg[3], int missed_periods,
@ -442,6 +416,7 @@ static void psi_avgs_work(struct work_struct *work)
struct delayed_work *dwork;
struct psi_group *group;
u32 changed_states;
bool nonidle;
u64 now;
dwork = to_delayed_work(work);
@ -452,6 +427,7 @@ static void psi_avgs_work(struct work_struct *work)
now = sched_clock();
collect_percpu_times(group, PSI_AVGS, &changed_states);
nonidle = changed_states & (1 << PSI_NONIDLE);
/*
* If there is task activity, periodically fold the per-cpu
* times and feed samples into the running averages. If things
@ -462,7 +438,7 @@ static void psi_avgs_work(struct work_struct *work)
if (now >= group->avg_next_update)
group->avg_next_update = update_averages(group, now);
if (changed_states & PSI_STATE_RESCHEDULE) {
if (nonidle) {
schedule_delayed_work(dwork, nsecs_to_jiffies(
group->avg_next_update - now) + 1);
}