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 3E55DC77B7A for ; Thu, 25 May 2023 06:45:44 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 8FF6710ED0F; Thu, 25 May 2023 06:45:43 +0000 (UTC) Received: from mga07.intel.com (mga07.intel.com [134.134.136.100]) by gabe.freedesktop.org (Postfix) with ESMTPS id BD24B10E6B0; Thu, 25 May 2023 06:45:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1684997141; x=1716533141; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=sls89+aDfzj+zo9cjx73tQNm8S7wFlPFhfr7Asf2lzg=; b=bSZ21WW1Bo6w6QflcakDcmAloMezsdzP6LJIM+D7HK8JzNJglBcS0YzR l5yNcBcvXBamfWldbSl7WAsQdL7bCIEXOvfQTzD40GB6NiPG7qFlmMB3Z en2sS68DtEoM9llPfJiZo5QWgFeHaGxbO+R/6W+mBcZSeNc3SxApSfUlq kRbr8vCFMVY0sTncYHlLeRW+O1i3cBOQqKCcEGRfkNYSZOTT3NsM0Hg0i wA4Q+u2utaqZVhlVRAIs5DQ+aYLZUX4A1+lk/xaMm5SKxl7OYk3zBozF9 61tmKyberarrKuJQqgH8IKlbsbzaUgHh0QwiJA+ip+Q9fFDj1wR+kXs0u g==; X-IronPort-AV: E=McAfee;i="6600,9927,10720"; a="419522167" X-IronPort-AV: E=Sophos;i="6.00,190,1681196400"; d="scan'208";a="419522167" Received: from orsmga002.jf.intel.com ([10.7.209.21]) by orsmga105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 24 May 2023 23:45:41 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10720"; a="704685798" X-IronPort-AV: E=Sophos;i="6.00,190,1681196400"; d="scan'208";a="704685798" Received: from szwolins-mobl1.ger.corp.intel.com (HELO [10.213.31.180]) ([10.213.31.180]) by orsmga002-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 24 May 2023 23:45:39 -0700 Message-ID: <2ca66c7b-725f-854b-c855-86de031e23ec@intel.com> Date: Thu, 25 May 2023 08:45:37 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101 Firefox/102.0 Thunderbird/102.11.0 Content-Language: en-US To: Ashutosh Dixit , intel-gfx@lists.freedesktop.org References: <20230524215629.97920-1-ashutosh.dixit@intel.com> <20230524215629.97920-2-ashutosh.dixit@intel.com> From: Andrzej Hajda Organization: Intel Technology Poland sp. z o.o. - ul. Slowackiego 173, 80-298 Gdansk - KRS 101882 - NIP 957-07-52-316 In-Reply-To: <20230524215629.97920-2-ashutosh.dixit@intel.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Intel-gfx] [PATCH 1/2] drm/i915/pmu: Turn off the timer to sample frequencies when GT is parked X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: dri-devel@lists.freedesktop.org Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" On 24.05.2023 23:56, Ashutosh Dixit wrote: > pmu_needs_timer() keeps the timer running even when GT is parked, > ostensibly to sample requested/actual frequencies. However > frequency_sample() has the following: > > /* Report 0/0 (actual/requested) frequency while parked. */ > if (!intel_gt_pm_get_if_awake(gt)) > return; > > The above code prevents frequencies to be sampled while the GT is > parked. So we might as well turn off the sampling timer itself in this > case and save CPU cycles/power. > > v2: Instead of turning freq bits off, return false, since no counters will > run after this change when GT is parked (Tvrtko) > v3: Remove gpu_active argument of pmu_needs_timer (Andrzej) > > Signed-off-by: Ashutosh Dixit > Reviewed-by: Tvrtko Ursulin Reviewed-by: Andrzej Hajda Regards Andrzej > --- > drivers/gpu/drm/i915/i915_pmu.c | 16 +++++----------- > 1 file changed, 5 insertions(+), 11 deletions(-) > > diff --git a/drivers/gpu/drm/i915/i915_pmu.c b/drivers/gpu/drm/i915/i915_pmu.c > index a814583e19fd7..09313cf9316b4 100644 > --- a/drivers/gpu/drm/i915/i915_pmu.c > +++ b/drivers/gpu/drm/i915/i915_pmu.c > @@ -139,7 +139,7 @@ static u32 frequency_enabled_mask(void) > return mask; > } > > -static bool pmu_needs_timer(struct i915_pmu *pmu, bool gpu_active) > +static bool pmu_needs_timer(struct i915_pmu *pmu) > { > struct drm_i915_private *i915 = container_of(pmu, typeof(*i915), pmu); > u32 enable; > @@ -157,17 +157,11 @@ static bool pmu_needs_timer(struct i915_pmu *pmu, bool gpu_active) > */ > enable &= frequency_enabled_mask() | ENGINE_SAMPLE_MASK; > > - /* > - * When the GPU is idle per-engine counters do not need to be > - * running so clear those bits out. > - */ > - if (!gpu_active) > - enable &= ~ENGINE_SAMPLE_MASK; > /* > * Also there is software busyness tracking available we do not > * need the timer for I915_SAMPLE_BUSY counter. > */ > - else if (i915->caps.scheduler & I915_SCHEDULER_CAP_ENGINE_BUSY_STATS) > + if (i915->caps.scheduler & I915_SCHEDULER_CAP_ENGINE_BUSY_STATS) > enable &= ~BIT(I915_SAMPLE_BUSY); > > /* > @@ -295,7 +289,7 @@ static void park_rc6(struct intel_gt *gt) > > static void __i915_pmu_maybe_start_timer(struct i915_pmu *pmu) > { > - if (!pmu->timer_enabled && pmu_needs_timer(pmu, true)) { > + if (!pmu->timer_enabled && pmu_needs_timer(pmu)) { > pmu->timer_enabled = true; > pmu->timer_last = ktime_get(); > hrtimer_start_range_ns(&pmu->timer, > @@ -321,7 +315,7 @@ void i915_pmu_gt_parked(struct intel_gt *gt) > */ > pmu->unparked &= ~BIT(gt->info.id); > if (pmu->unparked == 0) > - pmu->timer_enabled = pmu_needs_timer(pmu, false); > + pmu->timer_enabled = false; > > spin_unlock_irq(&pmu->lock); > } > @@ -827,7 +821,7 @@ static void i915_pmu_disable(struct perf_event *event) > */ > if (--pmu->enable_count[bit] == 0) { > pmu->enable &= ~BIT(bit); > - pmu->timer_enabled &= pmu_needs_timer(pmu, true); > + pmu->timer_enabled &= pmu_needs_timer(pmu); > } > > spin_unlock_irqrestore(&pmu->lock, flags);