pSeries run as a guest and might need pv-qspinlock.
Signed-off-by: Pan Xinhui
---
arch/powerpc/kernel/Makefile | 1 +
arch/powerpc/platforms/pseries/Kconfig | 8
2 files changed, 9 insertions(+)
diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile
index fe
The default pv-qspinlock uses qspinlock(native version of pv-qspinlock).
pv_lock initialization should be done in bootstage with irq disabled.
And if we run as a guest with powerKVM/pHyp shared_processor mode,
restore pv_lock_ops callbacks to pv-qspinlock(pv version) which makes
full use of virtual
Add two corresponding helper functions to support pv-qspinlock.
For normal use, __spin_yield_cpu will confer current vcpu slices to the
target vcpu(say, a lock holder). If target vcpu is not specified or it
is in running state, such conferging to lpar happens or not depends.
Because hcall itself
This patch add basic code to enable qspinlock on powerpc. qspinlock is
one kind of fairlock implemention. And seen some performance improvement
under some scenarios.
queued_spin_unlock() release the lock by just one write of NULL to the
->locked field which sits at different places in the two endi
pseries will use qspinlock by default.
Signed-off-by: Pan Xinhui
---
arch/powerpc/platforms/pseries/Kconfig | 1 +
1 file changed, 1 insertion(+)
diff --git a/arch/powerpc/platforms/pseries/Kconfig
b/arch/powerpc/platforms/pseries/Kconfig
index bec90fb..f669323 100644
--- a/arch/powerpc/platfo
cmpxchg_release() is more lighweight than cmpxchg() on some archs(e.g.
PPC), moreover, in __pv_queued_spin_unlock() we only needs a RELEASE in
the fast path(pairing with *_try_lock() or *_lock()). And the slow path
has smp_store_release too. So it's safe to use cmpxchg_release here.
Suggested-by:
Hi All,
this is the fairlock patchset. You can apply them and build successfully.
patches are based on 4.8-rc4.
qspinlock can avoid waiter starved issue. It has about the same speed in
single-thread and it can be much faster in high contention situations
especially when the spinlock is embedded
*
** Apologize if you receive multiple copies of this email, or if its content is
irrelevant for you.
*
** Please forward for your contacts. Thank you very much!
*
-
WorldCIST'17 - 5th World Conference on Information Systems and Technologies
Porto santo Isalnd, Madeira, Portugal
11th-13
