kernel_samsung_sm7125

jenna

History

Heiko Carstens 36cd3c9f92 mutex: have non-spinning mutexes on s390 by default Impact: performance regression fix for s390 The adaptive spinning mutexes will not always do what one would expect on virtualized architectures like s390. Especially the cpu_relax() loop in mutex_spin_on_owner might hurt if the mutex holding cpu has been scheduled away by the hypervisor. We would end up in a cpu_relax() loop when there is no chance that the state of the mutex changes until the target cpu has been scheduled again by the hypervisor. For that reason we should change the default behaviour to no-spin on s390. We do have an instruction which allows to yield the current cpu in favour of a different target cpu. Also we have an instruction which allows us to figure out if the target cpu is physically backed. However we need to do some performance tests until we can come up with a solution that will do the right thing on s390. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> LKML-Reference: <20090409184834.7a0df7b2@osiris.boeblingen.de.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>		16 years ago
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appldata	…
boot	…
crypto	Merge branch 'for-linus' of git://git390.marist.edu/pub/scm/linux-2.6	16 years ago
hypfs	[S390] fix hypfs build failure	16 years ago
include/asm	Merge branch 'ipi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip	16 years ago
kernel	Simplify copy_thread()	16 years ago
kvm	Merge branch 'for-linus' of git://git390.marist.edu/pub/scm/linux-2.6	16 years ago
lib	…
math-emu	…
mm	[S390] cpumask: use mm_cpumask() wrapper	16 years ago
oprofile	…
Kconfig	mutex: have non-spinning mutexes on s390 by default	16 years ago
Kconfig.debug	generic debug pagealloc: build fix	16 years ago
Makefile	…
defconfig	…