Commit 6301cb95 authored by Thomas Gleixner's avatar Thomas Gleixner

sched: fix nr_uninterruptible accounting of frozen tasks really

commit e3c8ca83 (sched: do not count frozen tasks toward load) broke
the nr_uninterruptible accounting on freeze/thaw. On freeze the task
is excluded from accounting with a check for (task->flags &
PF_FROZEN), but that flag is cleared before the task is thawed. So
while we prevent that the task with state TASK_UNINTERRUPTIBLE
is accounted to nr_uninterruptible on freeze we decrement
nr_uninterruptible on thaw.

Use a separate flag which is handled by the freezing task itself. Set
it before calling the scheduler with TASK_UNINTERRUPTIBLE state and
clear it after we return from frozen state.

Cc: <>
Signed-off-by: default avatarThomas Gleixner <>
parent a468d389
......@@ -209,7 +209,7 @@ extern unsigned long long time_sync_thresh;
((task->state & (__TASK_STOPPED | __TASK_TRACED)) != 0)
#define task_contributes_to_load(task) \
((task->state & TASK_UNINTERRUPTIBLE) != 0 && \
(task->flags & PF_FROZEN) == 0)
(task->flags & PF_FREEZING) == 0)
#define __set_task_state(tsk, state_value) \
do { (tsk)->state = (state_value); } while (0)
......@@ -1680,6 +1680,7 @@ extern cputime_t task_gtime(struct task_struct *p);
#define PF_MEMALLOC 0x00000800 /* Allocating memory */
#define PF_FLUSHER 0x00001000 /* responsible for disk writeback */
#define PF_USED_MATH 0x00002000 /* if unset the fpu must be initialized before use */
#define PF_FREEZING 0x00004000 /* freeze in progress. do not account to load */
#define PF_NOFREEZE 0x00008000 /* this thread should not be frozen */
#define PF_FROZEN 0x00010000 /* frozen for system suspend */
#define PF_FSTRANS 0x00020000 /* inside a filesystem transaction */
......@@ -44,12 +44,19 @@ void refrigerator(void)
recalc_sigpending(); /* We sent fake signal, clean it up */
/* prevent accounting of that task to load */
current->flags |= PF_FREEZING;
for (;;) {
if (!frozen(current))
/* Remove the accounting blocker */
current->flags &= ~PF_FREEZING;
pr_debug("%s left refrigerator\n", current->comm);
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