From 560857de3064eb196a8f0f8b8df693b9cc07d9ac Mon Sep 17 00:00:00 2001 From: Josh Hunt Date: Mon, 19 Aug 2019 19:13:31 -0400 Subject: [PATCH] perf/x86/intel: Restrict period on Nehalem [ Upstream commit 44d3bbb6f5e501b873218142fe08cdf62a4ac1f3 ] We see our Nehalem machines reporting 'perfevents: irq loop stuck!' in some cases when using perf: perfevents: irq loop stuck! WARNING: CPU: 0 PID: 3485 at arch/x86/events/intel/core.c:2282 intel_pmu_handle_irq+0x37b/0x530 ... RIP: 0010:intel_pmu_handle_irq+0x37b/0x530 ... Call Trace: ? perf_event_nmi_handler+0x2e/0x50 ? intel_pmu_save_and_restart+0x50/0x50 perf_event_nmi_handler+0x2e/0x50 nmi_handle+0x6e/0x120 default_do_nmi+0x3e/0x100 do_nmi+0x102/0x160 end_repeat_nmi+0x16/0x50 ... ? native_write_msr+0x6/0x20 ? native_write_msr+0x6/0x20 intel_pmu_enable_event+0x1ce/0x1f0 x86_pmu_start+0x78/0xa0 x86_pmu_enable+0x252/0x310 __perf_event_task_sched_in+0x181/0x190 ? __switch_to_asm+0x41/0x70 ? __switch_to_asm+0x35/0x70 ? __switch_to_asm+0x41/0x70 ? __switch_to_asm+0x35/0x70 finish_task_switch+0x158/0x260 __schedule+0x2f6/0x840 ? hrtimer_start_range_ns+0x153/0x210 schedule+0x32/0x80 schedule_hrtimeout_range_clock+0x8a/0x100 ? hrtimer_init+0x120/0x120 ep_poll+0x2f7/0x3a0 ? wake_up_q+0x60/0x60 do_epoll_wait+0xa9/0xc0 __x64_sys_epoll_wait+0x1a/0x20 do_syscall_64+0x4e/0x110 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7fdeb1e96c03 ... Signed-off-by: Peter Zijlstra (Intel) Cc: acme@kernel.org Cc: Josh Hunt Cc: bpuranda@akamai.com Cc: mingo@redhat.com Cc: jolsa@redhat.com Cc: tglx@linutronix.de Cc: namhyung@kernel.org Cc: alexander.shishkin@linux.intel.com Link: https://lkml.kernel.org/r/1566256411-18820-1-git-send-email-johunt@akamai.com Signed-off-by: Sasha Levin --- arch/x86/events/intel/core.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/arch/x86/events/intel/core.c b/arch/x86/events/intel/core.c index db5a2ba61753..2dd8b0d64295 100644 --- a/arch/x86/events/intel/core.c +++ b/arch/x86/events/intel/core.c @@ -3319,6 +3319,11 @@ static u64 bdw_limit_period(struct perf_event *event, u64 left) return left; } +static u64 nhm_limit_period(struct perf_event *event, u64 left) +{ + return max(left, 32ULL); +} + PMU_FORMAT_ATTR(event, "config:0-7" ); PMU_FORMAT_ATTR(umask, "config:8-15" ); PMU_FORMAT_ATTR(edge, "config:18" ); @@ -4115,6 +4120,7 @@ __init int intel_pmu_init(void) x86_pmu.pebs_constraints = intel_nehalem_pebs_event_constraints; x86_pmu.enable_all = intel_pmu_nhm_enable_all; x86_pmu.extra_regs = intel_nehalem_extra_regs; + x86_pmu.limit_period = nhm_limit_period; x86_pmu.cpu_events = nhm_events_attrs; -- GitLab