From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 055F8C433F5 for ; Mon, 10 Oct 2022 14:18:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:References:Cc:To:From: Subject:MIME-Version:Date:Message-ID:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=HP/S9WlxsL3GWrFeCAfWMFbbYYQxRQqG7X8Td+73ngA=; b=2aFceHfnWoR7R4 NGDIcTkR6MNTu5lsnUJgUGY+rqNxroz/gqZAcizfRvPuq2o2B0WwNl/keHefyUyMOUbHnNiN5BwFi Ay7UdSk1a0vE+BUqEt3FiiUrgHdgCIZzdf4iNL7FvPUhVhpehlJy+OX9JyZ2dz7b5LQ389JoZhiUB yT8NxeA5W+gbMhvXS6nYzPHXESIrzz1ihnQUt4JN3+BRFK6ckPYN2fU1CqrGZDN6XUBtKg++mNKKS UJPFfXEGHakOWx2KlGD7L1KABttpdTcpPstb5Fae3jJw4ZcskgDk81IiECFxKQixg0pve3D2jUK9a UGYx+z9oyZgMQxXtN3Cg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1ohtbK-001BGE-Nw; Mon, 10 Oct 2022 14:17:50 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1ohtbG-001BEr-Rn for linux-arm-kernel@lists.infradead.org; Mon, 10 Oct 2022 14:17:49 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 81F6E12FC; Mon, 10 Oct 2022 07:17:48 -0700 (PDT) Received: from [10.57.3.59] (unknown [10.57.3.59]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 09B043F766; Mon, 10 Oct 2022 07:17:40 -0700 (PDT) Message-ID: Date: Mon, 10 Oct 2022 15:17:39 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.11.0 Subject: Re: [PATCH V3 4/7] driver/perf/arm_pmu_platform: Add support for BRBE attributes detection Content-Language: en-US From: James Clark To: Anshuman Khandual Cc: linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, linux-arm-kernel@lists.infradead.org, peterz@infradead.org, acme@kernel.org, mark.rutland@arm.com, will@kernel.org, catalin.marinas@arm.com References: <20220929075857.158358-1-anshuman.khandual@arm.com> <20220929075857.158358-5-anshuman.khandual@arm.com> <02ce379c-c718-b72d-fc74-cd8c904265fb@arm.com> In-Reply-To: <02ce379c-c718-b72d-fc74-cd8c904265fb@arm.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20221010_071747_052967_068B37B1 X-CRM114-Status: GOOD ( 23.79 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 06/10/2022 14:37, James Clark wrote: > > > On 29/09/2022 08:58, Anshuman Khandual wrote: >> This adds arm pmu infrastrure to probe BRBE implementation's attributes via >> driver exported callbacks later. The actual BRBE feature detection will be >> added by the driver itself. >> >> CPU specific BRBE entries, cycle count, format support gets detected during >> PMU init. This information gets saved in per-cpu struct pmu_hw_events which >> later helps in operating BRBE during a perf event context. >> >> Cc: Will Deacon >> Cc: Mark Rutland >> Cc: linux-arm-kernel@lists.infradead.org >> Cc: linux-kernel@vger.kernel.org >> Signed-off-by: Anshuman Khandual >> --- >> drivers/perf/arm_pmu_platform.c | 34 +++++++++++++++++++++++++++++++++ >> 1 file changed, 34 insertions(+) >> >> diff --git a/drivers/perf/arm_pmu_platform.c b/drivers/perf/arm_pmu_platform.c >> index 933b96e243b8..acdc445081aa 100644 >> --- a/drivers/perf/arm_pmu_platform.c >> +++ b/drivers/perf/arm_pmu_platform.c >> @@ -172,6 +172,36 @@ static int armpmu_request_irqs(struct arm_pmu *armpmu) >> return err; >> } >> >> +static void arm_brbe_probe_cpu(void *info) >> +{ >> + struct pmu_hw_events *hw_events; >> + struct arm_pmu *armpmu = info; >> + >> + /* >> + * Return from here, if BRBE driver has not been >> + * implemented for this PMU. This helps prevent >> + * kernel crash later when brbe_probe() will be >> + * called on the PMU. >> + */ >> + if (!armpmu->brbe_probe) >> + return; >> + >> + hw_events = per_cpu_ptr(armpmu->hw_events, smp_processor_id()); >> + armpmu->brbe_probe(hw_events); >> +} >> + >> +static int armpmu_request_brbe(struct arm_pmu *armpmu) >> +{ >> + int cpu, err = 0; >> + >> + for_each_cpu(cpu, &armpmu->supported_cpus) { >> + err = smp_call_function_single(cpu, arm_brbe_probe_cpu, armpmu, 1); > > Hi Anshuman, > > I have LOCKDEP on and the patchset applied to perf/core (82aad7ff7) on > git://git.kernel.org/pub/scm/linux/kernel/git/peterz/queue.git and I get Can you confirm if this is currently the correct place to apply this to? I'm only getting 0 length branch stacks now. Seems like it could be something to do with the layout of perf samples because I know that was done in separate commits: sudo ./perf record -j any_call -- ls ./perf report -D | grep "branch stack" ... branch stack: nr:0 ... branch stack: nr:0 ... branch stack: nr:0 ... branch stack: nr:0 ... > this: > > armv8-pmu pmu: hw perfevents: no interrupt-affinity property, guessing. > brbe: implementation found on cpu 0 > > ============================= > [ BUG: Invalid wait context ] > 6.0.0-rc7 #38 Not tainted > ----------------------------- > kworker/u8:0/9 is trying to lock: > ffff000800855898 (&port_lock_key){....}-{3:3}, at: > pl011_console_write+0x148/0x240 > other info that might help us debug this: > context-{2:2} > 5 locks held by kworker/u8:0/9: > #0: ffff00080032a138 ((wq_completion)eval_map_wq){+.+.}-{0:0}, at: > process_one_work+0x200/0x6b0 > #1: ffff80000807bde0 > ((work_completion)(&eval_map_work)){+.+.}-{0:0}, at: > process_one_work+0x200/0x6b0 > #2: ffff80000aa3db70 (trace_event_sem){+.+.}-{4:4}, at: > trace_event_eval_update+0x28/0x420 > #3: ffff80000a9afe58 (console_lock){+.+.}-{0:0}, at: > vprintk_emit+0x130/0x380 > #4: ffff80000a9aff78 (console_owner){-...}-{0:0}, at: > console_emit_next_record.constprop.0+0x128/0x338 > stack backtrace: > CPU: 0 PID: 9 Comm: kworker/u8:0 Not tainted 6.0.0-rc7 #38 > Hardware name: Foundation-v8A (DT) > Workqueue: eval_map_wq eval_map_work_func > Call trace: > dump_backtrace+0x114/0x120 > show_stack+0x20/0x58 > dump_stack_lvl+0x9c/0xd8 > dump_stack+0x18/0x34 > __lock_acquire+0x17cc/0x1920 > lock_acquire+0x138/0x3b8 > _raw_spin_lock+0x58/0x70 > pl011_console_write+0x148/0x240 > console_emit_next_record.constprop.0+0x194/0x338 > console_unlock+0x18c/0x208 > vprintk_emit+0x24c/0x380 > vprintk_default+0x40/0x50 > vprintk+0xd4/0xf0 > _printk+0x68/0x90 > arm64_pmu_brbe_probe+0x10c/0x128 > armv8pmu_brbe_probe+0x18/0x28 > arm_brbe_probe_cpu+0x44/0x58 > __flush_smp_call_function_queue+0x1d0/0x440 > generic_smp_call_function_single_interrupt+0x20/0x78 > ipi_handler+0x98/0x368 > handle_percpu_devid_irq+0xc0/0x3a8 > generic_handle_domain_irq+0x34/0x50 > gic_handle_irq+0x58/0x138 > call_on_irq_stack+0x2c/0x58 > do_interrupt_handler+0x88/0x90 > el1_interrupt+0x40/0x78 > el1h_64_irq_handler+0x18/0x28 > el1h_64_irq+0x64/0x68 > trace_event_eval_update+0x114/0x420 > eval_map_work_func+0x30/0x40 > process_one_work+0x298/0x6b0 > worker_thread+0x54/0x408 > kthread+0x118/0x128 > ret_from_fork+0x10/0x20 > brbe: implementation found on cpu 1 > brbe: implementation found on cpu 2 > brbe: implementation found on cpu 3 > >> + if (err) >> + return err; >> + } >> + return err; >> +} >> + >> static void armpmu_free_irqs(struct arm_pmu *armpmu) >> { >> int cpu; >> @@ -229,6 +259,10 @@ int arm_pmu_device_probe(struct platform_device *pdev, >> if (ret) >> goto out_free_irqs; >> >> + ret = armpmu_request_brbe(pmu); >> + if (ret) >> + goto out_free_irqs; >> + >> ret = armpmu_register(pmu); >> if (ret) { >> dev_err(dev, "failed to register PMU devices!\n"); _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel