Revision 2db138bb9fa10f5652f55d3c3f427af54626a086 authored by Linus Torvalds on 07 February 2021, 17:37:37 UTC, committed by Linus Torvalds on 07 February 2021, 17:37:37 UTC
Pull Kbuild fixes from Masahiro Yamada:

 - Use the 'python3' command to invoke python scripts because some
   distributions do not provide the 'python' command any more.

 - Clean-up and update documents

 - Use pkg-config to search libcrypto

 - Fix duplicated debug flags

 - Ignore some more stubs in scripts/kallsyms.c

* tag 'kbuild-fixes-v5.11-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  kallsyms: fix nonconverging kallsyms table with lld
  kbuild: fix duplicated flags in DEBUG_CFLAGS
  scripts/clang-tools: switch explicitly to Python 3
  kbuild: remove PYTHON variable
  Documentation/llvm: Add a section about supported architectures
  Revert "checkpatch: add check for keyword 'boolean' in Kconfig definitions"
  scripts: use pkg-config to locate libcrypto
  kconfig: mconf: fix HOSTCC call
  doc: gcc-plugins: update gcc-plugins.rst
  kbuild: simplify GCC_PLUGINS enablement in dummy-tools/gcc
  Documentation/Kbuild: Remove references to gcc-plugin.sh
  scripts: switch explicitly to Python 3
2 parent s 825b599 + efe6e30
Raw File
features.h
/* SPDX-License-Identifier: GPL-2.0 */
/*
 * Only give sleepers 50% of their service deficit. This allows
 * them to run sooner, but does not allow tons of sleepers to
 * rip the spread apart.
 */
SCHED_FEAT(GENTLE_FAIR_SLEEPERS, true)

/*
 * Place new tasks ahead so that they do not starve already running
 * tasks
 */
SCHED_FEAT(START_DEBIT, true)

/*
 * Prefer to schedule the task we woke last (assuming it failed
 * wakeup-preemption), since its likely going to consume data we
 * touched, increases cache locality.
 */
SCHED_FEAT(NEXT_BUDDY, false)

/*
 * Prefer to schedule the task that ran last (when we did
 * wake-preempt) as that likely will touch the same data, increases
 * cache locality.
 */
SCHED_FEAT(LAST_BUDDY, true)

/*
 * Consider buddies to be cache hot, decreases the likelyness of a
 * cache buddy being migrated away, increases cache locality.
 */
SCHED_FEAT(CACHE_HOT_BUDDY, true)

/*
 * Allow wakeup-time preemption of the current task:
 */
SCHED_FEAT(WAKEUP_PREEMPTION, true)

SCHED_FEAT(HRTICK, false)
SCHED_FEAT(DOUBLE_TICK, false)

/*
 * Decrement CPU capacity based on time not spent running tasks
 */
SCHED_FEAT(NONTASK_CAPACITY, true)

/*
 * Queue remote wakeups on the target CPU and process them
 * using the scheduler IPI. Reduces rq->lock contention/bounces.
 */
SCHED_FEAT(TTWU_QUEUE, true)

/*
 * When doing wakeups, attempt to limit superfluous scans of the LLC domain.
 */
SCHED_FEAT(SIS_AVG_CPU, false)
SCHED_FEAT(SIS_PROP, true)

/*
 * Issue a WARN when we do multiple update_rq_clock() calls
 * in a single rq->lock section. Default disabled because the
 * annotations are not complete.
 */
SCHED_FEAT(WARN_DOUBLE_CLOCK, false)

#ifdef HAVE_RT_PUSH_IPI
/*
 * In order to avoid a thundering herd attack of CPUs that are
 * lowering their priorities at the same time, and there being
 * a single CPU that has an RT task that can migrate and is waiting
 * to run, where the other CPUs will try to take that CPUs
 * rq lock and possibly create a large contention, sending an
 * IPI to that CPU and let that CPU push the RT task to where
 * it should go may be a better scenario.
 */
SCHED_FEAT(RT_PUSH_IPI, true)
#endif

SCHED_FEAT(RT_RUNTIME_SHARE, false)
SCHED_FEAT(LB_MIN, false)
SCHED_FEAT(ATTACH_AGE_LOAD, true)

SCHED_FEAT(WA_IDLE, true)
SCHED_FEAT(WA_WEIGHT, true)
SCHED_FEAT(WA_BIAS, true)

/*
 * UtilEstimation. Use estimated CPU utilization.
 */
SCHED_FEAT(UTIL_EST, true)
SCHED_FEAT(UTIL_EST_FASTUP, true)
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