Goal is to have vmstat_shepherd to transfer from per-CPU counters to global counters remotely. For this, an atomic this_cpu_cmpxchg is necessary. Following the kernel convention for cmpxchg/cmpxchg_local, change ARM's this_cpu_cmpxchg_ helpers to be atomic, and add this_cpu_cmpxchg_local_ helpers which are not atomic. Signed-off-by: Marcelo Tosatti <mtosatti@xxxxxxxxxx> Index: linux-vmstat-remote/arch/arm64/include/asm/percpu.h =================================================================== --- linux-vmstat-remote.orig/arch/arm64/include/asm/percpu.h +++ linux-vmstat-remote/arch/arm64/include/asm/percpu.h @@ -232,13 +232,23 @@ PERCPU_RET_OP(add, add, ldadd) _pcp_protect_return(xchg_relaxed, pcp, val) #define this_cpu_cmpxchg_1(pcp, o, n) \ - _pcp_protect_return(cmpxchg_relaxed, pcp, o, n) + _pcp_protect_return(cmpxchg, pcp, o, n) #define this_cpu_cmpxchg_2(pcp, o, n) \ - _pcp_protect_return(cmpxchg_relaxed, pcp, o, n) + _pcp_protect_return(cmpxchg, pcp, o, n) #define this_cpu_cmpxchg_4(pcp, o, n) \ - _pcp_protect_return(cmpxchg_relaxed, pcp, o, n) + _pcp_protect_return(cmpxchg, pcp, o, n) #define this_cpu_cmpxchg_8(pcp, o, n) \ + _pcp_protect_return(cmpxchg, pcp, o, n) + +#define this_cpu_cmpxchg_local_1(pcp, o, n) \ _pcp_protect_return(cmpxchg_relaxed, pcp, o, n) +#define this_cpu_cmpxchg_local_2(pcp, o, n) \ + _pcp_protect_return(cmpxchg_relaxed, pcp, o, n) +#define this_cpu_cmpxchg_local_4(pcp, o, n) \ + _pcp_protect_return(cmpxchg_relaxed, pcp, o, n) +#define this_cpu_cmpxchg_local_8(pcp, o, n) \ + _pcp_protect_return(cmpxchg_relaxed, pcp, o, n) + #ifdef __KVM_NVHE_HYPERVISOR__ extern unsigned long __hyp_per_cpu_offset(unsigned int cpu);
