Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752876AbaBCM5Z (ORCPT ); Mon, 3 Feb 2014 07:57:25 -0500 Received: from mail-wg0-f42.google.com ([74.125.82.42]:40712 "EHLO mail-wg0-f42.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752497AbaBCM4f (ORCPT ); Mon, 3 Feb 2014 07:56:35 -0500 From: Stephane Eranian To: linux-kernel@vger.kernel.org Cc: peterz@infradead.org, mingo@elte.hu, acme@redhat.com, ak@linux.intel.com, zheng.z.yan@intel.com Subject: [PATCH v1 09/10] perf/x86/uncore: add hrtimer to SNB uncore IMC PMU Date: Mon, 3 Feb 2014 13:55:41 +0100 Message-Id: <1391432142-18723-10-git-send-email-eranian@google.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1391432142-18723-1-git-send-email-eranian@google.com> References: <1391432142-18723-1-git-send-email-eranian@google.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This patch is needed because that PMU uses 32-bit free running counters with no interrupt capabilities. On SNB/IVB/HSW, we used 20GB/s theoretical peak to calculate the hrtimer timeout necessary to avoid missing an overflow. That delay is set to 5s to be on the cautious side. The SNB IMC uses free running counters, which are handled via pseudo fixed counters. The SNB IMC PMU implementation supports an arbitrary number of events, because the counters are read-only. Therefore it is not possible to track active counters. Instead we put active events on a linked list which is then used by the hrtimer handler to update the SW counts. Signed-off-by: Stephane Eranian --- arch/x86/kernel/cpu/perf_event_intel_uncore.c | 12 ++++++++++++ arch/x86/kernel/cpu/perf_event_intel_uncore.h | 2 ++ 2 files changed, 14 insertions(+) diff --git a/arch/x86/kernel/cpu/perf_event_intel_uncore.c b/arch/x86/kernel/cpu/perf_event_intel_uncore.c index 8b1f81f..f76937e 100644 --- a/arch/x86/kernel/cpu/perf_event_intel_uncore.c +++ b/arch/x86/kernel/cpu/perf_event_intel_uncore.c @@ -1730,6 +1730,7 @@ static void snb_uncore_imc_init_box(struct intel_uncore_box *box) addr &= ~(PAGE_SIZE - 1); box->io_addr = ioremap(addr, SNB_UNCORE_PCI_IMC_MAP_SIZE); + box->hrtimer_duration = UNCORE_SNB_IMC_HRTIMER_INTERVAL; } static void snb_uncore_imc_enable_box(struct intel_uncore_box *box) @@ -3166,6 +3167,7 @@ static void uncore_perf_event_update(struct intel_uncore_box *box, struct perf_e static enum hrtimer_restart uncore_pmu_hrtimer(struct hrtimer *hrtimer) { struct intel_uncore_box *box; + struct perf_event *event; unsigned long flags; int bit; @@ -3178,6 +3180,14 @@ static enum hrtimer_restart uncore_pmu_hrtimer(struct hrtimer *hrtimer) */ local_irq_save(flags); + /* + * handle boxes with an active event list as opposed to active + * counters + */ + list_for_each_entry(event, &box->active_list, active_entry) { + uncore_perf_event_update(box, event); + } + for_each_set_bit(bit, box->active_mask, UNCORE_PMC_IDX_MAX) uncore_perf_event_update(box, box->events[bit]); @@ -3227,6 +3237,8 @@ static struct intel_uncore_box *uncore_alloc_box(struct intel_uncore_type *type, /* set default hrtimer timeout */ box->hrtimer_duration = UNCORE_PMU_HRTIMER_INTERVAL; + INIT_LIST_HEAD(&box->active_list); + return box; } diff --git a/arch/x86/kernel/cpu/perf_event_intel_uncore.h b/arch/x86/kernel/cpu/perf_event_intel_uncore.h index 0770da2..634de93 100644 --- a/arch/x86/kernel/cpu/perf_event_intel_uncore.h +++ b/arch/x86/kernel/cpu/perf_event_intel_uncore.h @@ -6,6 +6,7 @@ #define UNCORE_PMU_NAME_LEN 32 #define UNCORE_PMU_HRTIMER_INTERVAL (60LL * NSEC_PER_SEC) +#define UNCORE_SNB_IMC_HRTIMER_INTERVAL (5ULL * NSEC_PER_SEC) #define UNCORE_FIXED_EVENT 0xff #define UNCORE_PMC_IDX_MAX_GENERIC 8 @@ -492,6 +493,7 @@ struct intel_uncore_box { u64 hrtimer_duration; /* hrtimer timeout for this box */ struct hrtimer hrtimer; struct list_head list; + struct list_head active_list; void *io_addr; struct intel_uncore_extra_reg shared_regs[0]; }; -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/