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 gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (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 295BEC83F2F for ; Thu, 31 Aug 2023 22:02:39 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id ACEA110E6F5; Thu, 31 Aug 2023 22:02:38 +0000 (UTC) Received: from mgamail.intel.com (mgamail.intel.com [192.55.52.88]) by gabe.freedesktop.org (Postfix) with ESMTPS id 1A53C10E6F5 for ; Thu, 31 Aug 2023 22:02:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1693519356; x=1725055356; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=Ok2rC6sFuIQ5lLMAx0O4ajDwoNExGruJrBMiWdMDT/k=; b=bWY9JIRv9KXHkQ4PbkGlCQch5/ga5ch3p/OXu2BowLMXGeQqI1M7LqVF ICRiu/40NwCRUQR/NYpSqPzprRMhEPo2m3CI24rl5qeZbKb+ZeMSIcPHO jxBfX4NPvdhJ+RT255ia+rJ9bi2gKgla7KpDUN0SxpPUZRM1rnLDrJ9s5 Gq6AU1GrHqima7ZnLTmj/CkbVYPNsRJMgDgJ5x0ci0plSzKSlNmRT5v+s dYxb1GBYIog7wmGiwUCUPuhvcjqU15t/b8S+MiDs944Ik1JrzsCRltrYS UfQtF4ylCIkaUzWutkLRxSy8OHxUU6WKoyOt88qQsbGiqUb63H3vpE+fr Q==; X-IronPort-AV: E=McAfee;i="6600,9927,10819"; a="407072339" X-IronPort-AV: E=Sophos;i="6.02,217,1688454000"; d="scan'208";a="407072339" Received: from orsmga005.jf.intel.com ([10.7.209.41]) by fmsmga101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 31 Aug 2023 15:02:35 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10819"; a="913453943" X-IronPort-AV: E=Sophos;i="6.02,217,1688454000"; d="scan'208";a="913453943" Received: from aravind-dev.iind.intel.com (HELO [10.145.162.80]) ([10.145.162.80]) by orsmga005-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 31 Aug 2023 15:02:33 -0700 Message-ID: <496fa477-0361-5e65-e7a8-d3c0d02e114a@linux.intel.com> Date: Fri, 1 Sep 2023 03:41:09 +0530 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.13.0 Content-Language: en-US To: "Dixit, Ashutosh" References: <20230830051544.369643-1-aravind.iddamsetty@linux.intel.com> <20230830051544.369643-4-aravind.iddamsetty@linux.intel.com> <87a5u724xe.wl-ashutosh.dixit@intel.com> <3b85e034-b1a4-29d1-2e4f-08ea6562b6ba@linux.intel.com> <877cpb173l.wl-ashutosh.dixit@intel.com> From: Aravind Iddamsetty In-Reply-To: <877cpb173l.wl-ashutosh.dixit@intel.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Subject: Re: [Intel-xe] [PATCH v5 3/3] drm/xe/pmu: Enable PMU interface X-BeenThere: intel-xe@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel Xe graphics driver List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Bommu Krishnaiah , intel-xe@lists.freedesktop.org, Tvrtko Ursulin Errors-To: intel-xe-bounces@lists.freedesktop.org Sender: "Intel-xe" On 31/08/23 22:28, Dixit, Ashutosh wrote: HI Ashutosh, > On Thu, 31 Aug 2023 03:29:11 -0700, Aravind Iddamsetty wrote: > Hi Aravind, > > Hmm, what happened to the email formatting here? not sure, some how my email client is showing proper or I messed up. > >> On Tue, 29 Aug 2023 22:15:44 -0700, Aravind Iddamsetty wrote: >> >> diff --git a/drivers/gpu/drm/xe/xe_pmu.c b/drivers/gpu/drm/xe/xe_pmu.c >> new file mode 100644 >> index 000000000000..41dd422812ff >> --- /dev/null >> +++ b/drivers/gpu/drm/xe/xe_pmu.c >> @@ -0,0 +1,679 @@ >> +// SPDX-License-Identifier: MIT >> +/* >> + * Copyright © 2023 Intel Corporation >> + */ >> + >> +#include >> +#include >> +#include >> + >> +#include "regs/xe_gt_regs.h" >> +#include "xe_device.h" >> +#include "xe_gt_clock.h" >> +#include "xe_mmio.h" >> + >> +static cpumask_t xe_pmu_cpumask; >> +static unsigned int xe_pmu_target_cpu = -1; >> + >> +static unsigned int config_gt_id(const u64 config) >> +{ >> + return config >> __XE_PMU_GT_SHIFT; >> +} >> + >> +static u64 config_counter(const u64 config) >> +{ >> + return config & ~(~0ULL << __XE_PMU_GT_SHIFT); >> +} >> + >> +static int engine_busyness_sample_type(u64 config) >> +{ >> + int type = 0; >> >> >> Why initialize? The switch statement should have a default with a BUG/WARN_ON >> below? Also see the comment below. >> >> + >> + switch (config) { >> + case XE_PMU_RENDER_GROUP_BUSY(0): >> + type = __XE_SAMPLE_RENDER_GROUP_BUSY; >> + break; >> + case XE_PMU_COPY_GROUP_BUSY(0): >> + type = __XE_SAMPLE_COPY_GROUP_BUSY; >> + break; >> + case XE_PMU_MEDIA_GROUP_BUSY(0): >> + type = __XE_SAMPLE_MEDIA_GROUP_BUSY; >> + break; >> + case XE_PMU_ANY_ENGINE_GROUP_BUSY(0): >> + type = __XE_SAMPLE_ANY_ENGINE_GROUP_BUSY; >> + break; >> + } >> + >> + return type; >> +} >> >> >> I am thinking this function is not really needed. We can just do: >> >> int sample_type = config - 1; >> >> or >> >> int sample_type = config_counter(config) - 1; >> >> It might not always be true in future, the configs can start from any range. > Disagree. This is uapi. Once it is exposed it cannot change. I am talking > about this: > > +#define XE_PMU_INTERRUPTS(gt) ___XE_PMU_OTHER(gt, 0) > +#define XE_PMU_RENDER_GROUP_BUSY(gt) ___XE_PMU_OTHER(gt, 1) > +#define XE_PMU_COPY_GROUP_BUSY(gt) ___XE_PMU_OTHER(gt, 2) > +#define XE_PMU_MEDIA_GROUP_BUSY(gt) ___XE_PMU_OTHER(gt, 3) > +#define XE_PMU_ANY_ENGINE_GROUP_BUSY(gt) ___XE_PMU_OTHER(gt, 4) > > How can this "start from any range"? We can only add new counters after > these, not before these, correct? I didn't mean to say that these particular one's would change but any future new events that might fall into these categories might start from a different range. sorry for the confusion. Your suggestion makes it looks simple but somehow i wanted to tie this to the enums we defined in sample array, so ya will check one more time if it doesn't really makes any sense will clean it up. > >> in engine_group_busyness_read? See comment at __xe_pmu_event_read below. >> >> + >> +static void xe_pmu_event_destroy(struct perf_event *event) >> +{ >> + struct xe_device *xe = >> + container_of(event->pmu, typeof(*xe), pmu.base); >> + >> + drm_WARN_ON(&xe->drm, event->parent); >> + >> + drm_dev_put(&xe->drm); >> +} >> + >> +static u64 __engine_group_busyness_read(struct xe_gt *gt, int sample_type) >> +{ >> + u64 val = 0; > No need to initialize here I think. We are not really expecting to drop > into the default case, which should be caught much before we enter this > function. > >> + >> + switch (sample_type) { >> + case __XE_SAMPLE_RENDER_GROUP_BUSY: >> + val = xe_mmio_read32(gt, XE_OAG_RENDER_BUSY_FREE); >> + break; >> + case __XE_SAMPLE_COPY_GROUP_BUSY: >> + val = xe_mmio_read32(gt, XE_OAG_BLT_BUSY_FREE); >> + break; >> + case __XE_SAMPLE_MEDIA_GROUP_BUSY: >> + val = xe_mmio_read32(gt, XE_OAG_ANY_MEDIA_FF_BUSY_FREE); >> + break; >> + case __XE_SAMPLE_ANY_ENGINE_GROUP_BUSY: >> + val = xe_mmio_read32(gt, XE_OAG_RC0_ANY_ENGINE_BUSY_FREE); >> + break; >> + default: >> + drm_warn(>->tile->xe->drm, "unknown pmu event\n"); >> + } >> + >> + return xe_gt_clock_cycles_to_ns(gt, val * 16); >> +} >> + >> +static u64 engine_group_busyness_read(struct xe_gt *gt, u64 config) >> +{ >> + int sample_type = engine_busyness_sample_type(config); >> >> >> If config is event->attr.config, this can just be 'config_counter(config) - 1'. >> See comment at __xe_pmu_event_read below. >> >> + const unsigned int gt_id = gt->info.id; >> + struct xe_device *xe = gt->tile->xe; >> + struct xe_pmu *pmu = &xe->pmu; >> + unsigned long flags; >> + bool device_awake; >> + u64 val; >> + >> + device_awake = xe_device_mem_access_get_if_ongoing(xe); >> + if (device_awake) { >> + XE_WARN_ON(xe_force_wake_get(gt_to_fw(gt), XE_FW_GT)); >> + val = __engine_group_busyness_read(gt, sample_type); >> + XE_WARN_ON(xe_force_wake_put(gt_to_fw(gt), XE_FW_GT)); >> + xe_device_mem_access_put(xe); >> + } >> + >> + spin_lock_irqsave(&pmu->lock, flags); >> + >> + if (device_awake) >> + pmu->sample[gt_id][sample_type] = val; >> + else >> + val = pmu->sample[gt_id][sample_type]; >> + >> + spin_unlock_irqrestore(&pmu->lock, flags); >> + >> + return val; >> +} >> + >> +static void engine_group_busyness_store(struct xe_gt *gt) >> +{ >> + struct xe_pmu *pmu = >->tile->xe->pmu; >> + unsigned int gt_id = gt->info.id; >> + unsigned long flags; >> + int i; >> + >> + spin_lock_irqsave(&pmu->lock, flags); >> + >> + for (i = __XE_SAMPLE_RENDER_GROUP_BUSY; i <= __XE_SAMPLE_ANY_ENGINE_GROUP_BUSY; i++) { >> + pmu->sample[gt_id][i] = __engine_group_busyness_read(gt, i); >> >> >> This is not quite right. At the minimum we need to take forcewake >> here. Also since this is called in both suspend and runtime_suspend code >> paths we might also need to the take the runtime_pm reference. >> >> The pm reference and forcewake are already taken in suspend paths hence >> didn't add here again as this is called only from those paths. >> >> check xe_gt_suspend. > Sorry, you are right, I missed it. So this is fine. > > >> >> >> I think the simplest might be to just construct 'config' >> (event->attr.config) here and call engine_group_busyness_read? Something >> like: >> >> for (i = __XE_SAMPLE_RENDER_GROUP_BUSY; i <= __XE_SAMPLE_ANY_ENGINE_GROUP_BUSY; i++) { >> config = ; // Construct config using gt_id and i >> engine_group_busyness_read(gt, i); >> } >> >> This will automatically save the read values in pmu->sample[][] if the >> device is awake. Thoughts? >> >> I think this is best kept separate from usual read paths(which are >> atomic) didn't want to club them. Also because forcewakes and pm >> reference are taken separately in suspend path. > Sure, no changes needed here. Just get rid of the braces to keep checkpatch > happy. > > >> >> >> + } >> + >> + spin_unlock_irqrestore(&pmu->lock, flags); >> +} >> + >> +static int >> +config_status(struct xe_device *xe, u64 config) >> +{ >> + unsigned int max_gt_id = xe->info.gt_count > 1 ? 1 : 0; >> >> >> What is this for? See below. >> >> reminiscent of my previous code, will clean it up. >> >> >> >> + unsigned int gt_id = config_gt_id(config); >> + struct xe_gt *gt = xe_device_get_gt(xe, gt_id); >> + >> + if (gt_id > max_gt_id) >> >> >> Maybe this can just be: >> >> if (gt_id >= XE_PMU_MAX_GT) >> >> + return -ENOENT; >> + >> + switch (config_counter(config)) { >> + case XE_PMU_INTERRUPTS(0): >> + if (gt_id) >> + return -ENOENT; >> + break; >> + case XE_PMU_RENDER_GROUP_BUSY(0): >> + case XE_PMU_COPY_GROUP_BUSY(0): >> + case XE_PMU_ANY_ENGINE_GROUP_BUSY(0): >> + if (gt->info.type == XE_GT_TYPE_MEDIA) >> + return -ENOENT; >> + break; >> + case XE_PMU_MEDIA_GROUP_BUSY(0): >> + if (!(gt->info.engine_mask & (BIT(XE_HW_ENGINE_VCS0) | BIT(XE_HW_ENGINE_VECS0)))) >> + return -ENOENT; >> + break; >> + default: >> + return -ENOENT; >> + } >> + >> + return 0; >> +} >> + >> +static int xe_pmu_event_init(struct perf_event *event) >> +{ >> + struct xe_device *xe = >> + container_of(event->pmu, typeof(*xe), pmu.base); >> + struct xe_pmu *pmu = &xe->pmu; >> + int ret; >> + >> + if (pmu->closed) >> + return -ENODEV; >> + >> + if (event->attr.type != event->pmu->type) >> + return -ENOENT; >> + >> + /* unsupported modes and filters */ >> + if (event->attr.sample_period) /* no sampling */ >> + return -EINVAL; >> + >> + if (has_branch_stack(event)) >> + return -EOPNOTSUPP; >> + >> + if (event->cpu < 0) >> + return -EINVAL; >> + >> + /* only allow running on one cpu at a time */ >> + if (!cpumask_test_cpu(event->cpu, &xe_pmu_cpumask)) >> + return -EINVAL; >> + >> + ret = config_status(xe, event->attr.config); >> + if (ret) >> + return ret; >> + >> + if (!event->parent) { >> + drm_dev_get(&xe->drm); >> + event->destroy = xe_pmu_event_destroy; >> + } >> + >> + return 0; >> +} >> + >> +static u64 __xe_pmu_event_read(struct perf_event *event) >> +{ >> + struct xe_device *xe = >> + container_of(event->pmu, typeof(*xe), pmu.base); >> + const unsigned int gt_id = config_gt_id(event->attr.config); >> + const u64 config = config_counter(event->attr.config); >> >> >> Probably nit but this config being different from event->attr.config is >> confusing. Let's use 'event->attr.config' throughout as argument to >> functions and use config_counter() to get rid of gt_id. So get rid of this >> config variable. >> >> + struct xe_gt *gt = xe_device_get_gt(xe, gt_id); >> + struct xe_pmu *pmu = &xe->pmu; >> + u64 val = 0; >> + >> + switch (config) { >> >> >> switch (config_counter(event->attr.config)) >> >> + case XE_PMU_INTERRUPTS(0): >> + val = READ_ONCE(pmu->irq_count); >> + break; >> + case XE_PMU_RENDER_GROUP_BUSY(0): >> + case XE_PMU_COPY_GROUP_BUSY(0): >> + case XE_PMU_ANY_ENGINE_GROUP_BUSY(0): >> + case XE_PMU_MEDIA_GROUP_BUSY(0): >> + val = engine_group_busyness_read(gt, config); >> >> >> engine_group_busyness_read(gt, event->attr.config); >> >> hmmm ok. >> >> >> >> Also, need a default case. >> >> + } >> + >> + return val; >> +} >> + >> +static void xe_pmu_event_read(struct perf_event *event) >> +{ >> + struct xe_device *xe = >> + container_of(event->pmu, typeof(*xe), pmu.base); >> + struct hw_perf_event *hwc = &event->hw; >> + struct xe_pmu *pmu = &xe->pmu; >> + u64 prev, new; >> + >> + if (pmu->closed) { >> + event->hw.state = PERF_HES_STOPPED; >> + return; >> + } >> +again: >> + prev = local64_read(&hwc->prev_count); >> + new = __xe_pmu_event_read(event); >> + >> + if (local64_cmpxchg(&hwc->prev_count, prev, new) != prev) >> + goto again; >> + >> + local64_add(new - prev, &event->count); >> +} >> + >> +static void xe_pmu_enable(struct perf_event *event) >> +{ >> + /* >> + * Store the current counter value so we can report the correct delta >> + * for all listeners. Even when the event was already enabled and has >> + * an existing non-zero value. >> + */ >> + local64_set(&event->hw.prev_count, __xe_pmu_event_read(event)); >> >> >> Right now nothing is being enabled here (unlike i915) so the function name >> xe_pmu_enable looks weird. Not sure, maybe leave as is for when things get >> added in the future? >> >> +static int xe_pmu_cpu_online(unsigned int cpu, struct hlist_node *node) >> +{ >> + struct xe_pmu *pmu = hlist_entry_safe(node, typeof(*pmu), cpuhp.node); >> + >> + BUG_ON(!pmu->base.event_init); >> + >> + /* Select the first online CPU as a designated reader. */ >> + if (cpumask_empty(&xe_pmu_cpumask)) >> + cpumask_set_cpu(cpu, &xe_pmu_cpumask); >> + >> + return 0; >> +} >> + >> +static int xe_pmu_cpu_offline(unsigned int cpu, struct hlist_node *node) >> +{ >> + struct xe_pmu *pmu = hlist_entry_safe(node, typeof(*pmu), cpuhp.node); >> + unsigned int target = xe_pmu_target_cpu; >> + >> + BUG_ON(!pmu->base.event_init); >> >> >> nit but wondering if we should remove these two BUG_ON's (and save a couple >> of checkpatch warnings even though the BUG_ON's are in i915) and just do >> something like: >> >> if (!pmu->base.event_init) >> return 0; >> >> The reason for the BUG_ON's seems to be that these functions can be called >> after module_init but before probe. >> >> xe_pmu_cpu_online() doesn't depend on pmu at all so looks like the BUG_ON >> can just be dropped? >> >> the xe_pmu_cpu_online/offline are not invoked when they are registered with >> cpuhp_setup_state_multi, but rather when cpuhp_state_add_instance() is called >> which is done post the PMU is initialized hence the check for BUG_ON. > cpuhp_setup_state_multi is called at module_init > time. cpuhp_state_add_instance is called from xe_pmu_register, i.e. during > device probe when pmu->base.event_init is already initialized. Therefore > seems even less reason to have the BUG_ON's. that is true even, so will remove the BUG_ON. > > Just a few minor issues left now so I am hoping we can wrap this marathon > review up soon :) ya i'm waiting for the same :) Thanks, Aravind. > > Thanks. > -- > Ashutosh