linux-stable.git/kernel/sched, branch v4.19.63

sched/fair: Fix "runnable_avg_yN_inv" not used warnings

2019-07-26T07:14:08+00:00

[ Upstream commit 509466b7d480bc5d22e90b9fbe6122ae0e2fbe39 ]

runnable_avg_yN_inv[] is only used in kernel/sched/pelt.c but was
included in several other places because they need other macros all
came from kernel/sched/sched-pelt.h which was generated by
Documentation/scheduler/sched-pelt. As the result, it causes compilation
a lot of warnings,

  kernel/sched/sched-pelt.h:4:18: warning: 'runnable_avg_yN_inv' defined but not used [-Wunused-const-variable=]
  kernel/sched/sched-pelt.h:4:18: warning: 'runnable_avg_yN_inv' defined but not used [-Wunused-const-variable=]
  kernel/sched/sched-pelt.h:4:18: warning: 'runnable_avg_yN_inv' defined but not used [-Wunused-const-variable=]
  ...

Silence it by appending the __maybe_unused attribute for it, so all
generated variables and macros can still be kept in the same file.

Signed-off-by: Qian Cai 
Signed-off-by: Peter Zijlstra (Intel) 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Link: https://lkml.kernel.org/r/1559596304-31581-1-git-send-email-cai@lca.pw
Signed-off-by: Ingo Molnar 
Signed-off-by: Sasha Levin

sched/core: Add __sched tag for io_schedule()

2019-07-26T07:14:08+00:00

[ Upstream commit e3b929b0a184edb35531153c5afcaebb09014f9d ]

Non-inline io_schedule() was introduced in:

  commit 10ab56434f2f ("sched/core: Separate out io_schedule_prepare() and io_schedule_finish()")

Keep in line with io_schedule_timeout(), otherwise "/proc//wchan" will
report io_schedule() rather than its callers when waiting for IO.

Reported-by: Jilong Kou 
Signed-off-by: Gao Xiang 
Signed-off-by: Peter Zijlstra (Intel) 
Acked-by: Tejun Heo 
Cc: Andrew Morton 
Cc: Linus Torvalds 
Cc: Miao Xie 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Fixes: 10ab56434f2f ("sched/core: Separate out io_schedule_prepare() and io_schedule_finish()")
Link: https://lkml.kernel.org/r/20190603091338.2695-1-gaoxiang25@huawei.com
Signed-off-by: Ingo Molnar 
Signed-off-by: Sasha Levin

jump_label: move 'asm goto' support test to Kconfig

2019-06-04T06:02:34+00:00

commit e9666d10a5677a494260d60d1fa0b73cc7646eb3 upstream.

Currently, CONFIG_JUMP_LABEL just means "I _want_ to use jump label".

The jump label is controlled by HAVE_JUMP_LABEL, which is defined
like this:

  #if defined(CC_HAVE_ASM_GOTO) && defined(CONFIG_JUMP_LABEL)
  # define HAVE_JUMP_LABEL
  #endif

We can improve this by testing 'asm goto' support in Kconfig, then
make JUMP_LABEL depend on CC_HAS_ASM_GOTO.

Ugly #ifdef HAVE_JUMP_LABEL will go away, and CONFIG_JUMP_LABEL will
match to the real kernel capability.

Signed-off-by: Masahiro Yamada 
Acked-by: Michael Ellerman  (powerpc)
Tested-by: Sedat Dilek 
[nc: Fix trivial conflicts in 4.19
     arch/xtensa/kernel/jump_label.c doesn't exist yet
     Ensured CC_HAVE_ASM_GOTO and HAVE_JUMP_LABEL were sufficiently
     eliminated]
Signed-off-by: Nathan Chancellor 
Signed-off-by: Greg Kroah-Hartman

sched/core: Handle overflow in cpu_shares_write_u64

2019-05-31T13:46:19+00:00

[ Upstream commit 5b61d50ab4ef590f5e1d4df15cd2cea5f5715308 ]

Bit shift in scale_load() could overflow shares. This patch saturates
it to MAX_SHARES like following sched_group_set_shares().

Example:

 # echo 9223372036854776832 > cpu.shares
 # cat cpu.shares

Before patch: 1024
After pattch: 262144

Signed-off-by: Konstantin Khlebnikov 
Acked-by: Peter Zijlstra 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Link: http://lkml.kernel.org/r/155125501891.293431.3345233332801109696.stgit@buzz
Signed-off-by: Ingo Molnar 
Signed-off-by: Sasha Levin

sched/rt: Check integer overflow at usec to nsec conversion

2019-05-31T13:46:19+00:00

[ Upstream commit 1a010e29cfa00fee2888fd2fd4983f848cbafb58 ]

Example of unhandled overflows:

 # echo 18446744073709651 > cpu.rt_runtime_us
 # cat cpu.rt_runtime_us
 99

 # echo 18446744073709900 > cpu.rt_period_us
 # cat cpu.rt_period_us
 348

After this patch they will fail with -EINVAL.

Signed-off-by: Konstantin Khlebnikov 
Acked-by: Peter Zijlstra 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Link: http://lkml.kernel.org/r/155125501739.293431.5252197504404771496.stgit@buzz
Signed-off-by: Ingo Molnar 
Signed-off-by: Sasha Levin

sched/core: Check quota and period overflow at usec to nsec conversion

2019-05-31T13:46:19+00:00

[ Upstream commit 1a8b4540db732ca16c9e43ac7c08b1b8f0b252d8 ]

Large values could overflow u64 and pass following sanity checks.

 # echo 18446744073750000 > cpu.cfs_period_us
 # cat cpu.cfs_period_us
 40448

 # echo 18446744073750000 > cpu.cfs_quota_us
 # cat cpu.cfs_quota_us
 40448

After this patch they will fail with -EINVAL.

Signed-off-by: Konstantin Khlebnikov 
Acked-by: Peter Zijlstra 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Link: http://lkml.kernel.org/r/155125502079.293431.3947497929372138600.stgit@buzz
Signed-off-by: Ingo Molnar 
Signed-off-by: Sasha Levin

sched/nohz: Run NOHZ idle load balancer on HK_FLAG_MISC CPUs

2019-05-31T13:46:14+00:00

[ Upstream commit 9b019acb72e4b5741d88e8936d6f200ed44b66b2 ]

The NOHZ idle balancer runs on the lowest idle CPU. This can
interfere with isolated CPUs, so confine it to HK_FLAG_MISC
housekeeping CPUs.

HK_FLAG_SCHED is not used for this because it is not set anywhere
at the moment. This could be folded into HK_FLAG_SCHED once that
option is fixed.

The problem was observed with increased jitter on an application
running on CPU0, caused by NOHZ idle load balancing being run on
CPU1 (an SMT sibling).

Signed-off-by: Nicholas Piggin 
Signed-off-by: Peter Zijlstra (Intel) 
Cc: Frederic Weisbecker 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Link: https://lkml.kernel.org/r/20190412042613.28930-1-npiggin@gmail.com
Signed-off-by: Ingo Molnar 
Signed-off-by: Sasha Levin

sched/cpufreq: Fix kobject memleak

2019-05-25T16:23:45+00:00

[ Upstream commit 9a4f26cc98d81b67ecc23b890c28e2df324e29f3 ]

Currently the error return path from kobject_init_and_add() is not
followed by a call to kobject_put() - which means we are leaking
the kobject.

Fix it by adding a call to kobject_put() in the error path of
kobject_init_and_add().

Signed-off-by: Tobin C. Harding 
Cc: Greg Kroah-Hartman 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Rafael J. Wysocki 
Cc: Thomas Gleixner 
Cc: Tobin C. Harding 
Cc: Vincent Guittot 
Cc: Viresh Kumar 
Link: http://lkml.kernel.org/r/20190430001144.24890-1-tobin@kernel.org
Signed-off-by: Ingo Molnar 
Signed-off-by: Sasha Levin

sched/deadline: Correctly handle active 0-lag timers

2019-05-02T07:58:56+00:00

commit 1b02cd6a2d7f3e2a6a5262887d2cb2912083e42f upstream.

syzbot reported the following warning:

   [ ] WARNING: CPU: 4 PID: 17089 at kernel/sched/deadline.c:255 task_non_contending+0xae0/0x1950

line 255 of deadline.c is:

	WARN_ON(hrtimer_active(&dl_se->inactive_timer));

in task_non_contending().

Unfortunately, in some cases (for example, a deadline task
continuosly blocking and waking immediately) it can happen that
a task blocks (and task_non_contending() is called) while the
0-lag timer is still active.

In this case, the safest thing to do is to immediately decrease
the running bandwidth of the task, without trying to re-arm the 0-lag timer.

Signed-off-by: luca abeni 
Signed-off-by: Peter Zijlstra (Intel) 
Acked-by: Juri Lelli 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: chengjian (D) 
Link: https://lkml.kernel.org/r/20190325131530.34706-1-luca.abeni@santannapisa.it
Signed-off-by: Ingo Molnar 
Signed-off-by: Greg Kroah-Hartman

sched/numa: Fix a possible divide-by-zero

2019-05-02T07:58:54+00:00

commit a860fa7b96e1a1c974556327aa1aee852d434c21 upstream.

sched_clock_cpu() may not be consistent between CPUs. If a task
migrates to another CPU, then se.exec_start is set to that CPU's
rq_clock_task() by update_stats_curr_start(). Specifically, the new
value might be before the old value due to clock skew.

So then if in numa_get_avg_runtime() the expression:

  'now - p->last_task_numa_placement'

ends up as -1, then the divider '*period + 1' in task_numa_placement()
is 0 and things go bang. Similar to update_curr(), check if time goes
backwards to avoid this.

[ peterz: Wrote new changelog. ]
[ mingo: Tweaked the code comment. ]

Signed-off-by: Xie XiuQi 
Signed-off-by: Peter Zijlstra (Intel) 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: cj.chengjian@huawei.com
Cc: 
Link: http://lkml.kernel.org/r/20190425080016.GX11158@hirez.programming.kicks-ass.net
Signed-off-by: Ingo Molnar 
Signed-off-by: Greg Kroah-Hartman