Re: [PATCH v4 10/10] tracing/hyper-v: trace hyperv_mmu_flush_tlb_others()

Steven Rostedt
2017-06-05T15:50:54Z

On Wed, 24 May 2017 14:04:05 +0200
Vitaly Kuznetsov <vkuznets@redhat.com> wrote:

> Add Hyper-V tracing subsystem and trace hyperv_mmu_flush_tlb_others().
> Tracing is done the same way we do xen_mmu_flush_tlb_others().
>
> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
> Acked-by: K. Y. Srinivasan <kys@microsoft.com>
> Tested-by: Simon Xiao <sixiao@microsoft.com>
> Tested-by: Srikanth Myakam <v-srm@microsoft.com>
> ---
> MAINTAINERS | 1 +
> arch/x86/hyperv/mmu.c | 8 ++++++++
> arch/x86/include/asm/trace/hyperv.h | 34 ++++++++++++++++++++++++++++++++++
> 3 files changed, 43 insertions(+)
> create mode 100644 arch/x86/include/asm/trace/hyperv.h
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 9e98464..045e10a 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -6168,6 +6168,7 @@ M: Stephen Hemminger <sthemmin@microsoft.com>
> L: devel@linuxdriverproject.org
> S: Maintained
> F: arch/x86/include/asm/mshyperv.h
> +F: arch/x86/include/asm/trace/hyperv.h
> F: arch/x86/include/uapi/asm/hyperv.h
> F: arch/x86/kernel/cpu/mshyperv.c
> F: arch/x86/hyperv
> diff --git a/arch/x86/hyperv/mmu.c b/arch/x86/hyperv/mmu.c
> index c9cecb3..f6b5211 100644
> --- a/arch/x86/hyperv/mmu.c
> +++ b/arch/x86/hyperv/mmu.c
> @@ -6,6 +6,10 @@
> #include <asm/tlbflush.h>
> #include <asm/msr.h>
> #include <asm/fpu/api.h>
> +#include <asm/trace/hyperv.h>
> +
> +#define CREATE_TRACE_POINTS
> +DEFINE_TRACE(hyperv_mmu_flush_tlb_others);

The above looks very wrong. Why are you using "DEFINE_TRACE()" here?

The typical case is:

#define CREATE_TRACE_POINTS
#include <asm/trace/hyperv.h>

Does your patch even work?

-- Steve

>
> /* HvFlushVirtualAddressSpace, HvFlushVirtualAddressList hypercalls */
> struct hv_flush_pcpu {
> @@ -75,6 +79,8 @@ static void hyperv_flush_tlb_others(const struct cpumask *cpus,
> u64 status = -1ULL;
> int cpu, vcpu, gva_n, max_gvas;
>
> + trace_hyperv_mmu_flush_tlb_others(cpus, mm, start, end);
> +
> if (!pcpu_flush || !hv_hypercall_pg)
> goto do_native;
>
> @@ -161,6 +167,8 @@ static void hyperv_flush_tlb_others_ex(const struct cpumask *cpus,
> u64 status = -1ULL;
> int nr_bank = 0, max_gvas, gva_n;
>
> + trace_hyperv_mmu_flush_tlb_others(cpus, mm, start, end);
> +
> if (!pcpu_flush_ex || !hv_hypercall_pg)
> goto do_native;
>
> diff --git a/arch/x86/include/asm/trace/hyperv.h b/arch/x86/include/asm/trace/hyperv.h
> new file mode 100644
> index 0000000..e46a351
> --- /dev/null
> +++ b/arch/x86/include/asm/trace/hyperv.h
> @@ -0,0 +1,34 @@
> +#undef TRACE_SYSTEM
> +#define TRACE_SYSTEM hyperv
> +
> +#if !defined(_TRACE_HYPERV_H) || defined(TRACE_HEADER_MULTI_READ)
> +#define _TRACE_HYPERV_H
> +
> +#include <linux/tracepoint.h>
> +
> +#if IS_ENABLED(CONFIG_HYPERV)
> +
> +TRACE_EVENT(hyperv_mmu_flush_tlb_others,
> + TP_PROTO(const struct cpumask *cpus, struct mm_struct *mm,
> + unsigned long addr, unsigned long end),
> + TP_ARGS(cpus, mm, addr, end),
> + TP_STRUCT__entry(
> + __field(unsigned int, ncpus)
> + __field(struct mm_struct *, mm)
> + __field(unsigned long, addr)
> + __field(unsigned long, end)
> + ),
> + TP_fast_assign(__entry->ncpus = cpumask_weight(cpus);
> + __entry->mm = mm;
> + __entry->addr = addr,
> + __entry->end = end),
> + TP_printk("ncpus %d mm %p addr %lx, end %lx",
> + __entry->ncpus, __entry->mm, __entry->addr, __entry->end)
> + );
> +
> +#endif /* CONFIG_HYPERV */
> +
> +#endif /* _TRACE_HYPERV_H */
> +
> +/* This part must be outside protection */
> +#include <trace/define_trace.h>