Re: [PATCH 13/21] x86/intel_rdt/cqm: Add cpus file support

[Shivappa Vikas]

On Sun, 2 Jul 2017, Thomas Gleixner wrote:

On Mon, 26 Jun 2017, Vikas Shivappa wrote:

diff --git a/arch/x86/kernel/cpu/intel_rdt.h b/arch/x86/kernel/cpu/intel_rdt.h
index fdf3654..fec8ba9 100644
--- a/arch/x86/kernel/cpu/intel_rdt.h
+++ b/arch/x86/kernel/cpu/intel_rdt.h
@@ -37,6 +37,8 @@ struct mon_evt {
 extern bool rdt_alloc_enabled;
 extern int rdt_mon_features;

+DECLARE_PER_CPU_READ_MOSTLY(int, cpu_rmid);

u32

+DEFINE_PER_CPU_READ_MOSTLY(int, cpu_rmid);
 static inline struct rmid_entry *__rmid_entry(u32 rmid)

Bah. Please add a new line between the DEFINE... and the function.

But that whole thing is wrong. The per cpu default closid and rmid want to
be in a single place, not in two distinct per cpu variables.

struct rdt_cpu_default {
      u32       rmid;
      u32       closid;
};

DEFINE_PER_CPU_READ_MOSTLY(struct rdt_cpu_default, rdt_cpu_default);

or something like this. That way it's guaranteed that the context switch
code touches a single cache line for the per cpu defaults.

Will fix and add both rmid and closid into common struct.

Thanks,
Vikas

Thanks,

        tglx