* [patch 0/2] Directed yield.
@ 2006-09-15 11:30 Martin Schwidefsky
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From: Martin Schwidefsky @ 2006-09-15 11:30 UTC (permalink / raw)
To: linux-arch, mingo
Hi folks,
with CONFIG_PREEMPT=y the spin_lock/read_lock/write_lock functions are
defined in kernel/spinlock.c with a loop over _raw_##op##_trylock. If
the lock could not be taken cpu_relax is called. The architecture can't
choose to do something else instead of cpu_relax. To implement a
directed yield that gives up the timeslice of a virtual cpu in
favour of a specific cpu, the cpu_relax needs to be replaced with
something new: _raw_spin_relax, _raw_read_relax or _raw_write_relax.
Patch #01 introduces the new primitives and patch #02 has the s390
implementation for directed yield as example for the use of the
primitives.
--
blue skies,
Martin.
Martin Schwidefsky
Linux for zSeries Development & Services
IBM Deutschland Entwicklung GmbH
"Reality continues to ruin my life." - Calvin.
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2006-09-15 11:30 [patch 0/2] Directed yield Martin Schwidefsky
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