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SubjectRe: [PATCH V5] perf: Add PERF_SAMPLE_PHYS_ADDR
On Thu, Aug 17, 2017 at 02:17:23PM -0400, kan.liang@intel.com wrote:
> diff --git a/arch/x86/events/intel/ds.c b/arch/x86/events/intel/ds.c
> index a322fed..f0e8d9c 100644
> --- a/arch/x86/events/intel/ds.c
> +++ b/arch/x86/events/intel/ds.c
> @@ -1065,6 +1065,35 @@ static inline u64 intel_hsw_transaction(struct pebs_record_skl *pebs)
> return txn;
> }
>
> +static u64 dla_to_phys(u64 dla)
> +{
> + u64 phys_addr = 0;
> + struct page *p = NULL;
> +
> + if (dla >= TASK_SIZE) {
> + /* If it's vmalloc()d memory, leave phys_addr as 0 */
> + if (virt_addr_valid(dla) &&
> + !(dla >= VMALLOC_START && dla < VMALLOC_END))
> + phys_addr = (u64)virt_to_phys((void *)(uintptr_t)dla);
> + } else {
> + /*
> + * Walking the pages tables for user address.
> + * Interrupts are disabled, so it prevents any tear down
> + * of the page tables.
> + * Try IRQ-safe __get_user_pages_fast first.
> + * If failed, leave phys_addr as 0.
> + */
> + if ((current->mm != NULL) &&
> + (__get_user_pages_fast(dla, 1, 0, &p) == 1))
> + phys_addr = page_to_phys(p) + dla % PAGE_SIZE;
> +
> + if (p)
> + put_page(p);
> + }
> +
> + return phys_addr;
> +}

Is this in any way x86 specific? AFAICT this should work in generic code
as long as data->addr is provided.

> static void setup_pebs_sample_data(struct perf_event *event,
> struct pt_regs *iregs, void *__pebs,
> struct perf_sample_data *data,
> @@ -1179,6 +1208,9 @@ static void setup_pebs_sample_data(struct perf_event *event,
> x86_pmu.intel_cap.pebs_format >= 1)
> data->addr = pebs->dla;
>
> + if ((sample_type & PERF_SAMPLE_PHYS_ADDR) && (data->addr != 0))
> + data->phys_addr = dla_to_phys(data->addr);
> +
> if (x86_pmu.intel_cap.pebs_format >= 2) {
> /* Only set the TSX weight when no memory weight. */
> if ((sample_type & PERF_SAMPLE_WEIGHT) && !fll)


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