releases/4.19.153/sched-features-fix-config_jump_label-case.patch

   1 From 02c2586bfbf3302dfdcbdfca4ee840928b64aa47 Mon Sep 17 00:00:00 2001
   2 From: Sasha Levin <sashal@kernel.org>
   3 Date: Tue, 13 Oct 2020 07:31:14 +0200
   4 Subject: sched/features: Fix !CONFIG_JUMP_LABEL case
   5
   6 From: Juri Lelli <juri.lelli@redhat.com>
   7
   8 [ Upstream commit a73f863af4ce9730795eab7097fb2102e6854365 ]
   9
  10 Commit:
  11
  12   765cc3a4b224e ("sched/core: Optimize sched_feat() for !CONFIG_SCHED_DEBUG builds")
  13
  14 made sched features static for !CONFIG_SCHED_DEBUG configurations, but
  15 overlooked the CONFIG_SCHED_DEBUG=y and !CONFIG_JUMP_LABEL cases.
  16
  17 For the latter echoing changes to /sys/kernel/debug/sched_features has
  18 the nasty effect of effectively changing what sched_features reports,
  19 but without actually changing the scheduler behaviour (since different
  20 translation units get different sysctl_sched_features).
  21
  22 Fix CONFIG_SCHED_DEBUG=y and !CONFIG_JUMP_LABEL configurations by properly
  23 restructuring ifdefs.
  24
  25 Fixes: 765cc3a4b224e ("sched/core: Optimize sched_feat() for !CONFIG_SCHED_DEBUG builds")
  26 Co-developed-by: Daniel Bristot de Oliveira <bristot@redhat.com>
  27 Signed-off-by: Daniel Bristot de Oliveira <bristot@redhat.com>
  28 Signed-off-by: Juri Lelli <juri.lelli@redhat.com>
  29 Signed-off-by: Ingo Molnar <mingo@kernel.org>
  30 Acked-by: Patrick Bellasi <patrick.bellasi@matbug.net>
  31 Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
  32 Link: https://lore.kernel.org/r/20201013053114.160628-1-juri.lelli@redhat.com
  33 Signed-off-by: Sasha Levin <sashal@kernel.org>
  34 ---
  35  kernel/sched/core.c  |  2 +-
  36  kernel/sched/sched.h | 13 ++++++++++---
  37  2 files changed, 11 insertions(+), 4 deletions(-)
  38
  39 diff --git a/kernel/sched/core.c b/kernel/sched/core.c
  40 index faef74f632620..b166320f7633e 100644
  41 --- a/kernel/sched/core.c
  42 +++ b/kernel/sched/core.c
  43 @@ -24,7 +24,7 @@
  44
  45  DEFINE_PER_CPU_SHARED_ALIGNED(struct rq, runqueues);
  46
  47 -#if defined(CONFIG_SCHED_DEBUG) && defined(CONFIG_JUMP_LABEL)
  48 +#ifdef CONFIG_SCHED_DEBUG
  49  /*
  50   * Debugging: various feature bits
  51   *
  52 diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
  53 index 5f0eb4565957f..41b7954be68b7 100644
  54 --- a/kernel/sched/sched.h
  55 +++ b/kernel/sched/sched.h
  56 @@ -1361,7 +1361,7 @@ enum {
  57
  58  #undef SCHED_FEAT
  59
  60 -#if defined(CONFIG_SCHED_DEBUG) && defined(CONFIG_JUMP_LABEL)
  61 +#ifdef CONFIG_SCHED_DEBUG
  62
  63  /*
  64   * To support run-time toggling of sched features, all the translation units
  65 @@ -1369,6 +1369,7 @@ enum {
  66   */
  67  extern const_debug unsigned int sysctl_sched_features;
  68
  69 +#ifdef CONFIG_JUMP_LABEL
  70  #define SCHED_FEAT(name, enabled)                                      \
  71  static __always_inline bool static_branch_##name(struct static_key *key) \
  72  {                                                                      \
  73 @@ -1381,7 +1382,13 @@ static __always_inline bool static_branch_##name(struct static_key *key) \
  74  extern struct static_key sched_feat_keys[__SCHED_FEAT_NR];
  75  #define sched_feat(x) (static_branch_##x(&sched_feat_keys[__SCHED_FEAT_##x]))
  76
  77 -#else /* !(SCHED_DEBUG && CONFIG_JUMP_LABEL) */
  78 +#else /* !CONFIG_JUMP_LABEL */
  79 +
  80 +#define sched_feat(x) (sysctl_sched_features & (1UL << __SCHED_FEAT_##x))
  81 +
  82 +#endif /* CONFIG_JUMP_LABEL */
  83 +
  84 +#else /* !SCHED_DEBUG */
  85
  86  /*
  87   * Each translation unit has its own copy of sysctl_sched_features to allow
  88 @@ -1397,7 +1404,7 @@ static const_debug __maybe_unused unsigned int sysctl_sched_features =
  89
  90  #define sched_feat(x) !!(sysctl_sched_features & (1UL << __SCHED_FEAT_##x))
  91
  92 -#endif /* SCHED_DEBUG && CONFIG_JUMP_LABEL */
  93 +#endif /* SCHED_DEBUG */
  94
  95  extern struct static_key_false sched_numa_balancing;
  96  extern struct static_key_false sched_schedstats;
  97 --
  98 2.25.1
  99