Skip to main content
  • Home
  • Development
  • Documentation
  • Donate
  • Operational login
  • Browse the archive

swh logo
SoftwareHeritage
Software
Heritage
Archive
Features
  • Search

  • Downloads

  • Save code now

  • Add forge now

  • Help

  • 9650ed3
  • /
  • kernel
  • /
  • sched
  • /
  • features.h
Raw File Download

To reference or cite the objects present in the Software Heritage archive, permalinks based on SoftWare Hash IDentifiers (SWHIDs) must be used.
Select below a type of object currently browsed in order to display its associated SWHID and permalink.

  • content
  • directory
content badge
swh:1:cnt:319ed0e8a3477fca87edd42afbf7726b4ea36f0a
directory badge
swh:1:dir:4334fcbd1e56f78eb2fa018341aac67d7a67a81f

This interface enables to generate software citations, provided that the root directory of browsed objects contains a citation.cff or codemeta.json file.
Select below a type of object currently browsed in order to generate citations for them.

  • content
  • directory
(requires biblatex-software package)
Generating citation ...
(requires biblatex-software package)
Generating citation ...
features.h
/*
 * 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)
SCHED_FEAT(LB_BIAS, true)

/*
 * 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, true)
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)

back to top

Software Heritage — Copyright (C) 2015–2026, The Software Heritage developers. License: GNU AGPLv3+.
The source code of Software Heritage itself is available on our development forge.
The source code files archived by Software Heritage are available under their own copyright and licenses.
Terms of use: Archive access, API— Content policy— Contact— JavaScript license information— Web API