Precise event sampling on AMD versus intel: quantitative and qualitative comparison

Precise event sampling is a profiling feature in commodity processors that can sample hardware events and accurately locate the instructions that trigger the events. This feature has been used in a large number of tools to detect application performance issues. Although precise event sampling is readily supported in modern multicore architectures, vendor supports exhibit great differences that affect their accuracy, stability, overhead, and functionality. This work presents the most comprehensive study to date on benchmarking the event sampling features of Intel PEBS and AMD IBS and performs in-depth analysis on key differences through series of microbenchmarks. Our qualitative and quantitative analysis shows that PEBS allows finer-grained and more accurate sampling of hardware events, while IBS offers richer set of information at each sample though it suffers from lower accuracy and stability. Moreover, OS signal delivery, which is a common method used by the profiling software, introduces significant time overhead to the original overhead incurred by the hardware mechanisms in both PEBS and IBS. We also found that both PEBS and IBS have bias in sampling events across multiple different locations in a code. Lastly, we demonstrate how our findings on microbenchmarks under different thread counts hold for a full-fledged profiling tool that runs on the state-of-the-art Intel and AMD machines. Overall our detailed comparisons serve as a great reference and provide invaluable information for hardware designers and profiling tool developers

Kajian Dampak Lingkungan Penerapan Teknologi Bioflok Pada Kegiatan Budidaya Udang Vaname Dengan Metode Life Cycle Assessment

Penerapan teknologi bioflok pada kegiatan budidaya vaname perlu dievaluasi, terkaitpenggunaan sumberdaya alam dan energi listrik yang berpotensi mengakibatkan dampaklingkungan disertai biaya investasi yang tinggi. Tujuan penelitian ini adalah menganalisisdampak lingkungan dan menentukan strategi pengelolaan budidaya udang berbasis teknologibioflok. Penelitian ini merupakan penelitian deskriptif kuantitatif dengan menggunakanmetode penaksiran daur hidup. Kajian dibatasi pada kegiatan pembesaran di tambak “cradleto farm gate”, unit yang digunakan adalah produksi 1 ton udang vaname. Hasil penelitian inimenunjukkan teknologi bioflok mampu meningkatkan produksi per satuan luas lahan yangdigunakan dengan ukuran panen ± 16,4 gr/ekor, nilai FCR 1,3, SR 86 - 92%, dan SGR 15,6%.Produksi per ton udang vaname menghasilkan dampak: acidification (Acd); 63.39 ± 15.37 kgSO2eq, eutrophication (Eut); 14.10 ± 3.28 kg PO4eq, ; global warming potential (GWP); 7336.77± 1,46 kg CO2eq, ; dan cumulative energy use (CEU) sebesar 101,64 ± 18.84 GJ. Strategipengelolaan perlu dilakukan dengan perbaikan manajemen pemberian pakan berbasis kualitasair, pengurangan konsumsi energi listrik, menerapkan panen bertahap dan menambahkankolam pengolahan limbah

The Effect of Work Motivation and Discipline on The Performance of The Leading Teachers of Madrasah

This article aims to determine the effect of motivation and work discipline on MA Unggulan Hikmatul Amanah Pacet. Respondents in this study were all teachers of the Supreme Court of Hikmatul Amanah Pacet, totaling 39 people. The results of the study found that: 1) The effect of work motivation on the performance of MA Hikmatul Amanah teachers was 23.9%, with a research t value of 1.589 0.05; 2) The effect of work discipline on Hikmatul Amanah's teacher performance was 40.9% with a research t value of 2.717 > t table of 1.687 and a significant value of 0.010 F table of 3.25. The influence of motivation and work discipline on teacher performance at MA Wisdom Amanah Pacet needs to be considered. Solutions to the problem are sought to be more helpful in improving teacher performance in the future

Analysis of sequence variations in low-density lipoprotein receptor gene among Malaysian patients with familial hypercholesterolemia

<p>Abstract</p> <p>Background</p> <p>Familial hypercholesterolemia is a genetic disorder mainly caused by defects in the low-density lipoprotein receptor gene. Few and limited analyses of familial hypercholesterolemia have been performed in Malaysia, and the underlying mutations therefore remain largely unknown.</p> <p>We studied a group of 154 unrelated FH patients from a northern area of Malaysia (Kelantan). The promoter region and exons 2-15 of the LDLR gene were screened by denaturing high-performance liquid chromatography to detect short deletions and nucleotide substitutions, and by multiplex ligation-dependent probe amplification to detect large rearrangements.</p> <p>Results</p> <p>A total of 29 gene sequence variants were reported in 117(76.0%) of the studied subjects. Eight different mutations (1 large rearrangement, 1 short deletion, 5 missense mutations, and 1 splice site mutation), and 21 variants. Eight gene sequence variants were reported for the first time and they were noticed in familial hypercholesterolemic patients, but not in controls (p.Asp100Asp, p.Asp139His, p.Arg471Gly, c.1705+117 T>G, c.1186+41T>A, 1705+112C>G, Dup exon 12 and p.Trp666ProfsX45). The incidence of the p.Arg471Gly variant was 11%. Patients with pathogenic mutations were younger, had significantly higher incidences of cardiovascular disease, xanthomas, and family history of hyperlipidemia, together with significantly higher total cholesterol and low density lipoprotein levels than patients with non-pathogenic variants.</p> <p>Conclusions</p> <p>Twenty-nine gene sequence variants occurred among FH patients; those with predicted pathogenicity were associated with higher incidences of cardiovascular diseases, tendon xanthomas, and higher total and low density lipoprotein levels compared to the rest. These results provide preliminary information on the mutation spectrum of this gene among patients with FH in Malaysia.</p

Diabetic retinopathy: current and future methods for early screening from a retinal hemodynamic and geometric approach

Diabetic retinopathy (DR) is a major disease and is the number one cause of blindness in the UK. In England alone, 4200 new cases appear every year and 1280 lead to blindness. DR is a result of diabetes mellitus, which affects the retina of the eye and specifically the vessel structure. Elevated levels of glucose cause a malfunction in the cell structure, which affects the vessel wall and, in severe conditions, leads to their breakage. Much research has been carried out on detecting the different stages of DR but not enough versatile research has been carried out on the detection of early DR before the appearance of any lesions. In this review, the authors approach the topic from the functional side of the human eye and how hemodynamic factors that are impaired by diabetes affect the vascular structur

Precise event sampling-based data locality tools for AMD multicore architectures

We propose COMDETECTIVE+, an inter-thread communication analyzer, and REUSETRACKER+, a reuse distance analyzer, that leverage the hardware features in AMD processors to support low-overhead profiling. Both tools employ the instruction-based sampling (IBS) facility and debug registers in AMD processors to detect inter-thread communication and data reuse. Different from prior arts, COMDETECTIVE+ differentiates the communication into true and false sharing, and REUSETRACKER+ measures reuse distance in private and shared caches by also considering cache line invalidation with low overhead. Both tools can attribute the communications and reuses to source code lines. To our knowledge these tools are two of the few profiling tools designed specifically for AMD x86 architectures using IBS. Our tools are timely and relevant considering the rise in numbers of AMD processor based data centers and HPC systems. We perform experiments to evaluate the accuracy and overheads of the proposed tools on an AMD machine with two-socket EPYC 7352 processors. COMDETECTIVE+ exhibits high accuracy while introducing 5.14× runtime and 1.4× memory overheads. REUSETRACKER+ also displays high accuracy, which is 95%, with 11.76×runtime and 1.46× memory overheads. These overheads are much lower than the overheads of existing simulators and code instrumentation-based tools. Lastly, we demonstrate the usage of the tools by having COMDETECTIVE+ and REUSETRACKER+ facilitate the code refactoring of two data mining benchmarks to improve their performance by up to 29%