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ANDROID: cpu: Don't prevent hotplug from DL/BATCH/IDLE

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Commit c6e5f9d7cf ("ANDROID: cpu-hotplug: Always use real time
scheduling when hotplugging a CPU") tried to speed-up hotplug of
SCHED_NORMAL tasks by temporarily elevating them to SCHED_FIFO. But
while at it, it also prevented hotplug from SCHED_IDLE, SCHED_BATCH or
SCHED_DEADLINE for no apparent reason.

Since this is a userspace-visible change, and is unlikely to actually be
needed, change the patch logic to only optimize for SCHED_NORMAL tasks
and leave the others untouched.

Bug: 169238689
Fixes: c6e5f9d7cf ("ANDROID: cpu-hotplug: Always use real time
scheduling when hotplugging a CPU")
Signed-off-by: Quentin Perret <qperret@google.com>
Change-Id: I4d9e88b15fee56e7d234826e2eaea306a69328bb
This commit is contained in:
Quentin Perret 2020-10-26 17:00:34 +00:00 committed by Greg Kroah-Hartman
parent d8d3d3b4db
commit 9da1f37103
1 changed files with 1 additions and 5 deletions
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6
kernel/cpu.c
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@ -1195,10 +1195,8 @@ static int switch_to_rt_policy(void)
if (policy == SCHED_NORMAL)
/* Switch to SCHED_FIFO from SCHED_NORMAL. */
return sched_setscheduler_nocheck(current, SCHED_FIFO, &param);
else if (policy == SCHED_FIFO || policy == SCHED_RR)
return 1;
else
return -EPERM;
return 1;
}
static int switch_to_fair_policy(void)
@ -1293,8 +1291,6 @@ static int cpu_up(unsigned int cpu, enum cpuhp_state target)
*/
switch_err = switch_to_rt_policy();
if (switch_err < 0)
return switch_err;
err = try_online_node(cpu_to_node(cpu));
if (err)