perfmon: add polling overflow implementation in perfmon

1 files changed, 4 insertions, 34 deletions

diff --git a/arch/x86/machine/pmu_amd.c b/arch/x86/machine/pmu_amd.c
index 34df620..8e56bfa 100644
--- a/arch/x86/machine/pmu_amd.c
+++ b/arch/x86/machine/pmu_amd.c
@@ -21,6 +21,7 @@
 #include <stdint.h>
 
 #include <kern/init.h>
+#include <kern/clock.h>
 #include <kern/log.h>
 #include <kern/perfmon.h>
 #include <machine/cpu.h>
@@ -175,7 +176,6 @@ pmu_amd_start(unsigned int pmc_id, unsigned int raw_event_id)
     /* TODO Handle PERFMON_EF_KERN/PERFMON_EF_USER */
     high = code->event_select >> 8;
     low = PMU_AMD_EVTSEL_EN
-          | PMU_AMD_EVTSEL_INT
           | PMU_AMD_EVTSEL_OS
           | PMU_AMD_EVTSEL_USR
           | (code->umask << 8)
@@ -205,38 +205,6 @@ pmu_amd_write(unsigned int pmc_id, uint64_t value)
     cpu_set_msr64(PMU_AMD_MSR_PERCTR0 + pmc_id, value);
 }
 
-/*
- * TODO Make the perfmon module handle basic overflow handling by polling
- * counters.
- */
-static void
-pmu_amd_handle_of_intr_v1(void)
-{
-    struct pmu_amd *pmu;
-    uint64_t value, prev;
-    unsigned int mask;
-
-    pmu = pmu_amd_get();
-
-    for (unsigned int pmc_id = 0; pmc_id != PMU_AMD_NR_PMCS; pmc_id++) {
-        mask = (1U << pmc_id);
-
-        if (pmu->pmc_bm & mask) {
-            continue;
-        }
-
-        value = pmu_amd_read(pmc_id);
-        prev = perfmon_cpu_pmc_get_prev(pmc_id);
-
-        if (prev > value) {
-            /* Overflow */
-            perfmon_cpu_pmc_inc_of(pmc_id);
-            /* Prevents us from overflowing twice */
-            perfmon_cpu_pmc_set_prev(pmc_id, value);
-        }
-    }
-}
-
 static int __init
 pmu_amd_setup(void)
 {
@@ -259,7 +227,9 @@ pmu_amd_setup(void)
     pmu->pmc_bm = (1U << PMU_AMD_NR_PMCS) - 1;
 
     pmu_driver.pmc_width = PMU_AMD_PMC_WIDTH;
-    pmu_driver.of_max_ticks = 1UL << (pmu_driver.pmc_width - 1);
+    /* Set max_tick to half the number of instruction per seconds. */
+    pmu_driver.of_max_ticks =
+        (1UL << (pmu_driver.pmc_width - 1)) / (cpu_get_freq() / CLOCK_FREQ);
 
     pmu_driver.ops.info = pmu_amd_info;
     pmu_driver.ops.translate = pmu_amd_translate;