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[23.128.96.18]) by mx.google.com with ESMTP id b7si5957763ejq.611.2020.12.12.02.49.56; Sat, 12 Dec 2020 02:50:18 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; dkim=pass header.i=@linutronix.de header.s=2020 header.b=tQu+qL5j; dkim=neutral (no key) header.i=@linutronix.de header.s=2020e; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=QUARANTINE dis=NONE) header.from=linutronix.de Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2437478AbgLKJf5 (ORCPT + 99 others); Fri, 11 Dec 2020 04:35:57 -0500 Received: from Galois.linutronix.de ([193.142.43.55]:33400 "EHLO galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2405656AbgLKJfY (ORCPT ); Fri, 11 Dec 2020 04:35:24 -0500 Date: Fri, 11 Dec 2020 09:34:38 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1607679279; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=ou+kKfZCkWPvAo2ZhmDsF0nRC6jNnkhrcbBdDKBylPA=; b=tQu+qL5jnLForGAY+wBXxoclv04B1ULW1PzokeGHAByoerOF6Be/dbBqeP2sRsYROKanR9 DRPeElymGB4nMfhuKWsIGp3JwSzGMo5f+pc5cJ1NjxhNle6JMqya8LLZwHFKwQjzoodu13 qQGeU2tDmMuZUkZv3i8DvgrMHRUQxPr2ribR86RX/ApJTW0jGrDt2/nSGaxM4tIBVJSJyF BlZU8HrLSkcBp2j/TJvScbysughKsi0+Skhs82xPf+yaRJpUmeFxVGn4moR0cVTxoCNr+6 3MFKJcWKpERj3WiSy2U6t/RpSkJ28cgxnfXw3oIFb4nRMwClHCnW4UhPQLhgnA== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1607679279; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=ou+kKfZCkWPvAo2ZhmDsF0nRC6jNnkhrcbBdDKBylPA=; b=MHBFk58YhQC84pJCueUaye7b3TzkWGlITcXULLxkPVccwsLxsDtQlWX1y4COuy+m5S2iuJ 6H/1k5k0igtSMwDQ== From: "tip-bot2 for Giovanni Gherdovich" Sender: tip-bot2@linutronix.de Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: sched/core] x86, sched: Use midpoint of max_boost and max_P for frequency invariance on AMD EPYC Cc: Giovanni Gherdovich , "Peter Zijlstra (Intel)" , Ingo Molnar , x86@kernel.org, linux-kernel@vger.kernel.org In-Reply-To: <20201112182614.10700-3-ggherdovich@suse.cz> References: <20201112182614.10700-3-ggherdovich@suse.cz> MIME-Version: 1.0 Message-ID: <160767927880.3364.502191929718820704.tip-bot2@tip-bot2> Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The following commit has been merged into the sched/core branch of tip: Commit-ID: 976df7e5730e3ec8a7e192c09c10ce6e8db07e65 Gitweb: https://git.kernel.org/tip/976df7e5730e3ec8a7e192c09c10ce6e8db07e65 Author: Giovanni Gherdovich AuthorDate: Thu, 12 Nov 2020 19:26:13 +01:00 Committer: Ingo Molnar CommitterDate: Fri, 11 Dec 2020 10:29:55 +01:00 x86, sched: Use midpoint of max_boost and max_P for frequency invariance on AMD EPYC Frequency invariant accounting calculations need the ratio freq_curr/freq_max, but freq_max is unknown as it depends on dynamic power allocation between cores: AMD EPYC CPUs implement "Core Performance Boost". Three candidates are considered to estimate this value: - maximum non-boost frequency - maximum boost frequency - the mid point between the above two Experimental data on an AMD EPYC Zen2 machine slightly favors the third option, which is applied with this patch. The analysis uses the ondemand cpufreq governor as baseline, and compares it with schedutil in a number of configurations. Using the freq_max value described above offers a moderate advantage in performance and efficiency: sugov-max (freq_max=max_boost) performs the worst on tbench: less throughput and reduced efficiency than the other invariant-schedutil options (see "Data Overview" below). Consider that tbench is generally a problematic case as no schedutil version currently is better than ondemand. sugov-P0 (freq_max=max_P) is the worst on dbench, while the other sugov's can surpass ondemand with less filesystem latency and slightly increased efficiency. 1. DATA OVERVIEW 2. DETAILED PERFORMANCE TABLES 3. POWER CONSUMPTION TABLE 1. DATA OVERVIEW ================ sugov-noinv : non-invariant schedutil governor sugov-max : invariant schedutil, freq_max=max_boost sugov-mid : invariant schedutil, freq_max=midpoint sugov-P0 : invariant schedutil, freq_max=max_P perfgov : performance governor driver : acpi_cpufreq machine : AMD EPYC 7742 (Zen2, aka "Rome"), dual socket, 128 cores / 256 threads, SATA SSD storage, 250G of memory, XFS filesystem Benchmarks are described in the next section. Tilde (~) means the value is the same as baseline. - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ondemand perfgov sugov-noinv sugov-max sugov-mid sugov-P0 better if - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - PERFORMANCE RATIOS tbench 1.00 1.44 0.90 0.87 0.93 0.93 higher dbench 1.00 0.91 0.95 0.94 0.94 1.06 lower kernbench 1.00 0.93 ~ ~ ~ 0.97 lower gitsource 1.00 0.66 0.97 0.96 ~ 0.95 lower - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - PERFORMANCE-PER-WATT RATIOS tbench 1.00 1.16 0.84 0.84 0.88 0.85 higher dbench 1.00 1.03 1.02 1.02 1.02 0.93 higher kernbench 1.00 1.05 ~ ~ ~ ~ higher gitsource 1.00 1.46 1.04 1.04 ~ 1.05 higher 2. DETAILED PERFORMANCE TABLES ============================== Benchmark : tbench4 (i.e. dbench4 over the network, actually loopback) Varying parameter : number of clients Unit : MB/sec (higher is better) 5.9.0-ondemand (BASELINE) 5.9.0-perfgov 5.9.0-sugov-noinv - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Hmean 1 427.19 +- 0.16% ( ) 778.35 +- 0.10% ( 82.20%) 346.92 +- 0.14% ( -18.79%) Hmean 2 853.82 +- 0.09% ( ) 1536.23 +- 0.03% ( 79.93%) 694.36 +- 0.05% ( -18.68%) Hmean 4 1657.54 +- 0.12% ( ) 2938.18 +- 0.12% ( 77.26%) 1362.81 +- 0.11% ( -17.78%) Hmean 8 3301.87 +- 0.06% ( ) 5679.10 +- 0.04% ( 72.00%) 2693.35 +- 0.04% ( -18.43%) Hmean 16 6139.65 +- 0.05% ( ) 9498.81 +- 0.04% ( 54.71%) 4889.97 +- 0.17% ( -20.35%) Hmean 32 11170.28 +- 0.09% ( ) 17393.25 +- 0.08% ( 55.71%) 9104.55 +- 0.09% ( -18.49%) Hmean 64 19322.97 +- 0.17% ( ) 31573.91 +- 0.08% ( 63.40%) 18552.52 +- 0.40% ( -3.99%) Hmean 128 30383.71 +- 0.11% ( ) 37416.91 +- 0.15% ( 23.15%) 25938.70 +- 0.41% ( -14.63%) Hmean 256 31143.96 +- 0.41% ( ) 30908.76 +- 0.88% ( -0.76%) 29754.32 +- 0.24% ( -4.46%) Hmean 512 30858.49 +- 0.26% ( ) 38524.60 +- 1.19% ( 24.84%) 42080.39 +- 0.56% ( 36.37%) Hmean 1024 39187.37 +- 0.19% ( ) 36213.86 +- 0.26% ( -7.59%) 39555.98 +- 0.12% ( 0.94%) 5.9.0-sugov-max 5.9.0-sugov-mid 5.9.0-sugov-P0 - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Hmean 1 352.59 +- 1.03% ( -17.46%) 352.08 +- 0.75% ( -17.58%) 352.31 +- 1.48% ( -17.53%) Hmean 2 697.32 +- 0.08% ( -18.33%) 700.16 +- 0.20% ( -18.00%) 696.79 +- 0.06% ( -18.39%) Hmean 4 1369.88 +- 0.04% ( -17.35%) 1369.72 +- 0.07% ( -17.36%) 1365.91 +- 0.05% ( -17.59%) Hmean 8 2696.79 +- 0.04% ( -18.33%) 2711.06 +- 0.04% ( -17.89%) 2715.10 +- 0.61% ( -17.77%) Hmean 16 4725.03 +- 0.03% ( -23.04%) 4875.65 +- 0.02% ( -20.59%) 4953.05 +- 0.28% ( -19.33%) Hmean 32 9231.65 +- 0.10% ( -17.36%) 8704.89 +- 0.27% ( -22.07%) 10562.02 +- 0.36% ( -5.45%) Hmean 64 15364.27 +- 0.19% ( -20.49%) 17786.64 +- 0.15% ( -7.95%) 19665.40 +- 0.22% ( 1.77%) Hmean 128 42100.58 +- 0.13% ( 38.56%) 34946.28 +- 0.13% ( 15.02%) 38635.79 +- 0.06% ( 27.16%) Hmean 256 30660.23 +- 1.08% ( -1.55%) 32307.67 +- 0.54% ( 3.74%) 31153.27 +- 0.12% ( 0.03%) Hmean 512 24604.32 +- 0.14% ( -20.27%) 40408.50 +- 1.10% ( 30.95%) 38800.29 +- 1.23% ( 25.74%) Hmean 1024 35535.47 +- 0.28% ( -9.32%) 41070.38 +- 2.56% ( 4.81%) 31308.29 +- 2.52% ( -20.11%) Benchmark : dbench (filesystem stressor) Varying parameter : number of clients Unit : seconds (lower is better) NOTE-1: This dbench version measures the average latency of a set of filesystem operations, as we found the traditional dbench metric (throughput) to be misleading. NOTE-2: Due to high variability, we partition the original dataset and apply statistical bootrapping (a resampling method). Accuracy is reported in the form of 95% confidence intervals. 5.9.0-ondemand (BASELINE) 5.9.0-perfgov 5.9.0-sugov-noinv - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - SubAmean 1 98.79 +- 0.92 ( ) 83.36 +- 0.82 ( 15.62%) 84.82 +- 0.92 ( 14.14%) SubAmean 2 116.00 +- 0.89 ( ) 102.12 +- 0.77 ( 11.96%) 109.63 +- 0.89 ( 5.49%) SubAmean 4 149.90 +- 1.03 ( ) 132.12 +- 0.91 ( 11.86%) 143.90 +- 1.15 ( 4.00%) SubAmean 8 182.41 +- 1.13 ( ) 159.86 +- 0.93 ( 12.36%) 165.82 +- 1.03 ( 9.10%) SubAmean 16 237.83 +- 1.23 ( ) 219.46 +- 1.14 ( 7.72%) 229.28 +- 1.19 ( 3.59%) SubAmean 32 334.34 +- 1.49 ( ) 309.94 +- 1.42 ( 7.30%) 321.19 +- 1.36 ( 3.93%) SubAmean 64 576.61 +- 2.16 ( ) 540.75 +- 2.00 ( 6.22%) 551.27 +- 1.99 ( 4.39%) SubAmean 128 1350.07 +- 4.14 ( ) 1205.47 +- 3.20 ( 10.71%) 1280.26 +- 3.75 ( 5.17%) SubAmean 256 3444.42 +- 7.97 ( ) 3698.00 +- 27.43 ( -7.36%) 3494.14 +- 7.81 ( -1.44%) SubAmean 2048 39457.89 +- 29.01 ( ) 34105.33 +- 41.85 ( 13.57%) 39688.52 +- 36.26 ( -0.58%) 5.9.0-sugov-max 5.9.0-sugov-mid 5.9.0-sugov-P0 - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - SubAmean 1 85.68 +- 1.04 ( 13.27%) 84.16 +- 0.84 ( 14.81%) 83.99 +- 0.90 ( 14.99%) SubAmean 2 108.42 +- 0.95 ( 6.54%) 109.91 +- 1.39 ( 5.24%) 112.06 +- 0.91 ( 3.39%) SubAmean 4 136.90 +- 1.04 ( 8.67%) 137.59 +- 0.93 ( 8.21%) 136.55 +- 0.95 ( 8.91%) SubAmean 8 163.15 +- 0.96 ( 10.56%) 166.07 +- 1.02 ( 8.96%) 165.81 +- 0.99 ( 9.10%) SubAmean 16 224.86 +- 1.12 ( 5.45%) 223.83 +- 1.06 ( 5.89%) 230.66 +- 1.19 ( 3.01%) SubAmean 32 320.51 +- 1.38 ( 4.13%) 322.85 +- 1.49 ( 3.44%) 321.96 +- 1.46 ( 3.70%) SubAmean 64 553.25 +- 1.93 ( 4.05%) 554.19 +- 2.08 ( 3.89%) 562.26 +- 2.22 ( 2.49%) SubAmean 128 1264.35 +- 3.72 ( 6.35%) 1256.99 +- 3.46 ( 6.89%) 2018.97 +- 18.79 ( -49.55%) SubAmean 256 3466.25 +- 8.25 ( -0.63%) 3450.58 +- 8.44 ( -0.18%) 5032.12 +- 38.74 ( -46.09%) SubAmean 2048 39133.10 +- 45.71 ( 0.82%) 39905.95 +- 34.33 ( -1.14%) 53811.86 +-193.04 ( -36.38%) Benchmark : kernbench (kernel compilation) Varying parameter : number of jobs Unit : seconds (lower is better) 5.9.0-ondemand (BASELINE) 5.9.0-perfgov 5.9.0-sugov-noinv - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Amean 2 471.71 +- 26.61% ( ) 409.88 +- 16.99% ( 13.11%) 430.63 +- 0.18% ( 8.71%) Amean 4 211.87 +- 0.58% ( ) 194.03 +- 0.74% ( 8.42%) 215.33 +- 0.64% ( -1.63%) Amean 8 109.79 +- 1.27% ( ) 101.43 +- 1.53% ( 7.61%) 111.05 +- 1.95% ( -1.15%) Amean 16 59.50 +- 1.28% ( ) 55.61 +- 1.35% ( 6.55%) 59.65 +- 1.78% ( -0.24%) Amean 32 34.94 +- 1.22% ( ) 32.36 +- 1.95% ( 7.41%) 35.44 +- 0.63% ( -1.43%) Amean 64 22.58 +- 0.38% ( ) 20.97 +- 1.28% ( 7.11%) 22.41 +- 1.73% ( 0.74%) Amean 128 17.72 +- 0.44% ( ) 16.68 +- 0.32% ( 5.88%) 17.65 +- 0.96% ( 0.37%) Amean 256 16.44 +- 0.53% ( ) 15.76 +- 0.32% ( 4.18%) 16.76 +- 0.60% ( -1.93%) Amean 512 16.54 +- 0.21% ( ) 15.62 +- 0.41% ( 5.53%) 16.84 +- 0.85% ( -1.83%) 5.9.0-sugov-max 5.9.0-sugov-mid 5.9.0-sugov-P0 - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Amean 2 421.30 +- 0.24% ( 10.69%) 419.26 +- 0.15% ( 11.12%) 414.38 +- 0.33% ( 12.15%) Amean 4 217.81 +- 5.53% ( -2.80%) 211.63 +- 0.99% ( 0.12%) 208.43 +- 0.47% ( 1.63%) Amean 8 108.80 +- 0.43% ( 0.90%) 108.48 +- 1.44% ( 1.19%) 108.59 +- 3.08% ( 1.09%) Amean 16 58.84 +- 0.74% ( 1.12%) 58.37 +- 0.94% ( 1.91%) 57.78 +- 0.78% ( 2.90%) Amean 32 34.04 +- 2.00% ( 2.59%) 34.28 +- 1.18% ( 1.91%) 33.98 +- 2.21% ( 2.75%) Amean 64 22.22 +- 1.69% ( 1.60%) 22.27 +- 1.60% ( 1.38%) 22.25 +- 1.41% ( 1.47%) Amean 128 17.55 +- 0.24% ( 0.97%) 17.53 +- 0.94% ( 1.04%) 17.49 +- 0.43% ( 1.30%) Amean 256 16.51 +- 0.46% ( -0.40%) 16.48 +- 0.48% ( -0.19%) 16.44 +- 1.21% ( 0.00%) Amean 512 16.50 +- 0.35% ( 0.19%) 16.35 +- 0.42% ( 1.14%) 16.37 +- 0.33% ( 0.99%) Benchmark : gitsource (time to run the git unit test suite) Varying parameter : none Unit : seconds (lower is better) 5.9.0-ondemand (BASELINE) 5.9.0-perfgov 5.9.0-sugov-noinv - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Amean 1035.76 +- 0.30% ( ) 688.21 +- 0.04% ( 33.56%) 1003.85 +- 0.14% ( 3.08%) 5.9.0-sugov-max 5.9.0-sugov-mid 5.9.0-sugov-P0 - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Amean 995.82 +- 0.08% ( 3.86%) 1011.98 +- 0.03% ( 2.30%) 986.87 +- 0.19% ( 4.72%) 3. POWER CONSUMPTION TABLE ========================== Average power consumption (watts). - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ondemand perfgov sugov-noinv sugov-max sugov-mid sugov-P0 - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - tbench4 227.25 281.83 244.17 236.76 241.50 247.99 dbench4 151.97 161.87 157.08 158.10 158.06 153.73 kernbench 162.78 167.22 162.90 164.19 164.65 164.72 gitsource 133.65 139.00 133.04 134.43 134.18 134.32 Signed-off-by: Giovanni Gherdovich Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Ingo Molnar Link: https://lkml.kernel.org/r/20201112182614.10700-3-ggherdovich@suse.cz --- arch/x86/kernel/smpboot.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c index a4ab5cf..c5dd5f6 100644 --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -2054,6 +2054,8 @@ static bool amd_set_max_freq_ratio(void) } perf_ratio = div_u64(highest_perf * SCHED_CAPACITY_SCALE, nominal_perf); + /* midpoint between max_boost and max_P */ + perf_ratio = (perf_ratio + SCHED_CAPACITY_SCALE) >> 1; if (!perf_ratio) { pr_debug("Non-zero highest/nominal perf values led to a 0 ratio\n"); return false;