Displaying 2 results from an estimated 2 matches for "spin_begin".
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pi_begin
2020 Jul 24
0
[PATCH v4 6/6] powerpc: implement smp_cond_load_relaxed
...h
+++ b/arch/powerpc/include/asm/barrier.h
@@ -76,6 +76,20 @@ do { \
___p1; \
})
+#define smp_cond_load_relaxed(ptr, cond_expr) ({ \
+ typeof(ptr) __PTR = (ptr); \
+ __unqual_scalar_typeof(*ptr) VAL; \
+ VAL = READ_ONCE(*__PTR); \
+ if (unlikely(!(cond_expr))) { \
+ spin_begin(); \
+ do { \
+ VAL = READ_ONCE(*__PTR); \
+ } while (!(cond_expr)); \
+ spin_end(); \
+ } \
+ (typeof(*ptr))VAL; \
+})
+
#ifdef CONFIG_PPC_BOOK3S_64
#define NOSPEC_BARRIER_SLOT nop
#elif defined(CONFIG_PPC_FSL_BOOK3E)
--
2.23.0
2020 Jul 24
8
[PATCH v4 0/6] powerpc: queued spinlocks and rwlocks
Updated with everybody's feedback (thanks all), and more performance
results.
What I've found is I might have been measuring the worst load point for
the paravirt case, and by looking at a range of loads it's clear that
queued spinlocks are overall better even on PV, doubly so when you look
at the generally much improved worst case latencies.
I have defaulted it to N even though