From patchwork Fri Dec 11 11:19:13 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vineet Gupta X-Patchwork-Id: 555675 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from bombadil.infradead.org (bombadil.infradead.org [IPv6:2001:1868:205::9]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 665D9140317 for ; Fri, 11 Dec 2015 22:22:46 +1100 (AEDT) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1a7Lme-0003rU-T2; Fri, 11 Dec 2015 11:22:44 +0000 Received: from smtprelay.synopsys.com ([198.182.60.111]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1a7Lmc-0003lw-BD for linux-snps-arc@lists.infradead.org; Fri, 11 Dec 2015 11:22:43 +0000 Received: from us02secmta2.synopsys.com (us02secmta2.synopsys.com [10.12.235.98]) by smtprelay.synopsys.com (Postfix) with ESMTP id 2BBCF10C0ECF; Fri, 11 Dec 2015 03:22:22 -0800 (PST) Received: from us02secmta2.internal.synopsys.com (us02secmta2.internal.synopsys.com [127.0.0.1]) by us02secmta2.internal.synopsys.com (Service) with ESMTP id 17C2255F14; Fri, 11 Dec 2015 03:22:22 -0800 (PST) Received: from mailhost.synopsys.com (mailhost1.synopsys.com [10.12.238.239]) by us02secmta2.internal.synopsys.com (Service) with ESMTP id D224255F02; Fri, 11 Dec 2015 03:22:21 -0800 (PST) Received: from mailhost.synopsys.com (localhost [127.0.0.1]) by mailhost.synopsys.com (Postfix) with ESMTP id B7506880; Fri, 11 Dec 2015 03:22:21 -0800 (PST) Received: from us01wehtc1.internal.synopsys.com (us01wehtc1-vip.internal.synopsys.com [10.12.239.236]) by mailhost.synopsys.com (Postfix) with ESMTP id 9FE6887F; Fri, 11 Dec 2015 03:22:21 -0800 (PST) Received: from IN01WEHTCB.internal.synopsys.com (10.144.199.106) by us01wehtc1.internal.synopsys.com (10.12.239.231) with Microsoft SMTP Server (TLS) id 14.3.195.1; Fri, 11 Dec 2015 03:22:21 -0800 Received: from IN01WEHTCA.internal.synopsys.com (10.144.199.103) by IN01WEHTCB.internal.synopsys.com (10.144.199.105) with Microsoft SMTP Server (TLS) id 14.3.195.1; Fri, 11 Dec 2015 16:52:18 +0530 Received: from vineetg-E7440.internal.synopsys.com (10.12.197.182) by IN01WEHTCA.internal.synopsys.com (10.144.199.243) with Microsoft SMTP Server (TLS) id 14.3.195.1; Fri, 11 Dec 2015 16:52:17 +0530 From: Vineet Gupta To: Subject: [PATCH 3/3] ARCv2: perf: Ensure perf intr gets enabled on all cores Date: Fri, 11 Dec 2015 16:49:13 +0530 Message-ID: <1449832753-6767-4-git-send-email-vgupta@synopsys.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1449832753-6767-1-git-send-email-vgupta@synopsys.com> References: <1449832753-6767-1-git-send-email-vgupta@synopsys.com> MIME-Version: 1.0 X-Originating-IP: [10.12.197.182] X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20151211_032242_436799_4F78BF59 X-CRM114-Status: GOOD ( 11.37 ) X-Spam-Score: -2.6 (--) X-Spam-Report: SpamAssassin version 3.4.0 on bombadil.infradead.org summary: Content analysis details: (-2.6 points) pts rule name description ---- ---------------------- -------------------------------------------------- -0.7 RCVD_IN_DNSWL_LOW RBL: Sender listed at http://www.dnswl.org/, low trust [198.182.60.111 listed in list.dnswl.org] -0.0 RCVD_IN_MSPIKE_H4 RBL: Very Good reputation (+4) [198.182.60.111 listed in wl.mailspike.net] -0.0 T_RP_MATCHES_RCVD Envelope sender domain matches handover relay domain -1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] -0.0 RCVD_IN_MSPIKE_WL Mailspike good senders X-BeenThere: linux-snps-arc@lists.infradead.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: Linux on Synopsys ARC Processors List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Marc Zyngier , Vineet Gupta , Alexey Brodkin , linux-kernel@vger.kernel.org, Peter Zijlstra , Thomas Gleixner Sender: "linux-snps-arc" Errors-To: linux-snps-arc-bounces+incoming=patchwork.ozlabs.org@lists.infradead.org This was the second perf intr issue perf sampling on multicore requires intr to be enabled on all cores. ARC perf probe code used helper arc_request_percpu_irq() which calls - request_percpu_irq() on core0 - enable_percpu_irq() on all all cores (including core0) genirq requires that request be made ahead of enable call. However if perf probe happened on non core0 (observed on a 3.18 kernel), enable would get called ahead of request, failing obviously and rendering perf intr disabled on all such cores [ 11.120000] 1 ARC perf : 8 counters (48 bits), 113 conditions, [overflow IRQ support] [ 11.130000] 1 -----> enable_percpu_irq() IRQ 20 failed [ 11.140000] 3 -----> enable_percpu_irq() IRQ 20 failed [ 11.140000] 2 -----> enable_percpu_irq() IRQ 20 failed [ 11.140000] 0 =====> request_percpu_irq() IRQ 20 [ 11.140000] 0 -----> enable_percpu_irq() IRQ 20 Fix this fragility, by calling request_percpu_irq() on whatever core calls probe (there is no requirement on which core calls this anyways) and then calling enable on each cores. Interestingly this started as invesigation of STAR 9000838902: "sporadically IRQs enabled on perf prob" which was about occassional boot spew as request_percpu_irq got called non-locally (from an IPI), and re-enabled interrupts in following path proc_mkdir -> spin_unlock_irq() which the irq work code didn't like. | ARC perf : 8 counters (48 bits), 113 conditions, [overflow IRQ support] | | BUG: failure at ../kernel/irq_work.c:135/irq_work_run_list()! | CPU: 0 PID: 0 Comm: swapper/0 Not tainted 3.18.10-01127-g285efb8e66d1 #2 | | Stack Trace: | arc_unwind_core.constprop.1+0x94/0x104 | dump_stack+0x62/0x98 | irq_work_run_list+0xb0/0xb4 | irq_work_run+0x22/0x3c | do_IPI+0x74/0x9c | handle_irq_event_percpu+0x34/0x164 | handle_percpu_irq+0x58/0x78 | generic_handle_irq+0x1e/0x2c | arch_do_IRQ+0x3c/0x60 | ret_from_exception+0x0/0x8 Cc: Marc Zyngier Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-snps-arc@lists.infradead.org Cc: linux-kernel@vger.kernel.org Cc: Alexey Brodkin Signed-off-by: Vineet Gupta --- arch/arc/kernel/perf_event.c | 32 +++++++++----------------------- 1 file changed, 9 insertions(+), 23 deletions(-) diff --git a/arch/arc/kernel/perf_event.c b/arch/arc/kernel/perf_event.c index 0c08bb1ce15a..8b134cfe5e1f 100644 --- a/arch/arc/kernel/perf_event.c +++ b/arch/arc/kernel/perf_event.c @@ -428,12 +428,11 @@ static irqreturn_t arc_pmu_intr(int irq, void *dev) #endif /* CONFIG_ISA_ARCV2 */ -void arc_cpu_pmu_irq_init(void) +static void arc_cpu_pmu_irq_init(void *data) { - struct arc_pmu_cpu *pmu_cpu = this_cpu_ptr(&arc_pmu_cpu); + int irq = *(int *)data; - arc_request_percpu_irq(arc_pmu->irq, smp_processor_id(), arc_pmu_intr, - "ARC perf counters", pmu_cpu); + enable_percpu_irq(irq, IRQ_TYPE_NONE); /* Clear all pending interrupt flags */ write_aux_reg(ARC_REG_PCT_INT_ACT, 0xffffffff); @@ -515,7 +514,6 @@ static int arc_pmu_device_probe(struct platform_device *pdev) if (has_interrupts) { int irq = platform_get_irq(pdev, 0); - unsigned long flags; if (irq < 0) { pr_err("Cannot get IRQ number for the platform\n"); @@ -524,24 +522,12 @@ static int arc_pmu_device_probe(struct platform_device *pdev) arc_pmu->irq = irq; - /* - * arc_cpu_pmu_irq_init() needs to be called on all cores for - * their respective local PMU. - * However we use opencoded on_each_cpu() to ensure it is called - * on core0 first, so that arc_request_percpu_irq() sets up - * AUTOEN etc. Otherwise enable_percpu_irq() fails to enable - * perf IRQ on non master cores. - * see arc_request_percpu_irq() - */ - preempt_disable(); - local_irq_save(flags); - arc_cpu_pmu_irq_init(); - local_irq_restore(flags); - smp_call_function((smp_call_func_t)arc_cpu_pmu_irq_init, 0, 1); - preempt_enable(); - - /* Clean all pending interrupt flags */ - write_aux_reg(ARC_REG_PCT_INT_ACT, 0xffffffff); + /* intc map function ensures irq_set_percpu_devid() called */ + request_percpu_irq(irq, arc_pmu_intr, "ARC perf counters", + this_cpu_ptr(&arc_pmu_cpu)); + + on_each_cpu(arc_cpu_pmu_irq_init, &irq, 1); + } else arc_pmu->pmu.capabilities |= PERF_PMU_CAP_NO_INTERRUPT;