diff options
| -rw-r--r-- | sys/dev/hwpmc/hwpmc_amd.c | 13 |
1 files changed, 9 insertions, 4 deletions
diff --git a/sys/dev/hwpmc/hwpmc_amd.c b/sys/dev/hwpmc/hwpmc_amd.c index 6285f7f..3d92829 100644 --- a/sys/dev/hwpmc/hwpmc_amd.c +++ b/sys/dev/hwpmc/hwpmc_amd.c @@ -693,9 +693,14 @@ amd_intr(int cpu, uintptr_t eip, int usermode) * and which has a valid 'struct pmc' association * * If found, we call a helper to process the interrupt. + * + * If multiple PMCs interrupt at the same time, the AMD64 + * processor appears to deliver as many NMIs as there are + * outstanding PMC interrupts. Thus we need to only process + * one interrupt at a time. */ - for (i = 0; i < AMD_NPMCS-1; i++) { + for (i = 0; retval == 0 && i < AMD_NPMCS-1; i++) { ri = i + 1; /* row index; TSC is at ri == 0 */ @@ -712,6 +717,8 @@ amd_intr(int cpu, uintptr_t eip, int usermode) continue; } + retval = 1; /* found an interrupting PMC */ + /* stop the PMC, reload count */ evsel = AMD_PMC_EVSEL_0 + i; perfctr = AMD_PMC_PERFCTR_0 + i; @@ -726,12 +733,10 @@ amd_intr(int cpu, uintptr_t eip, int usermode) wrmsr(evsel, config & ~AMD_PMC_ENABLE); wrmsr(perfctr, AMD_RELOAD_COUNT_TO_PERFCTR_VALUE(v)); - /* restart if there was no error during logging */ + /* restart the counter if there was no error during logging */ error = pmc_process_interrupt(cpu, pm, eip, usermode); if (error == 0) wrmsr(evsel, config | AMD_PMC_ENABLE); - - retval = 1; /* found an interrupting PMC */ } atomic_add_int(retval ? &pmc_stats.pm_intr_processed : |
