Architectural techniques to extend multi-core performance scaling

Multi-cores have successfully delivered performance improvements over the past decade; however, they now face problems on two fronts: power and off-chip memory bandwidth. Dennard\u27s scaling is effectively coming to an end which has lead to a gradual increase in chip power dissipation. In addition, sustaining off-chip memory bandwidth has become harder due to the limited space for pins on the die and greater current needed to drive the increasing load . My thesis focuses on techniques to address the power and off-chip memory bandwidth challenges in order to avoid the premature end of the multi-core era. ^ In the first part of my thesis, I focus on techniques to address the power problem. One option to cope with the power limit, as suggested by some recent papers, is to ensure that an increasing number of cores are kept powered down (i.e., dark silicon) due to lack of power; but this option imposes a low upper bound on performance. The alternative option of customizing the cores to improve power efficiency may incur increased effort for hardware design, verification and test, and degraded programmability. I propose a gentler evolutionary path for multi-cores, called successive frequency unscaling ( SFU), to cope with the slowing of Dennard\u27s scaling. SFU keeps powered significantly more cores (compared to the option of keeping them \u27dark\u27) running at clock frequencies on the extended Pareto frontier that are successively lowered every generation to stay within the power budget. ^ In the second part of my thesis, I focus on techniques to avert the limited off-chip memory bandwidth problem. Die-stacking of DRAM on a processor die promises to continue scaling the pin bandwidth to off-chip memory. While the die-stacked DRAM is expected to be used as a cache, storing any part of the tag in the DRAM itself erodes the bandwidth advantage of die-stacking. As such, the on-die space overhead of the large DRAM cache\u27s tag is a concern. A well-known compromise is to employ a small on-die tag cache (T$) for the tag metadata while the full tag stays in the DRAM. However, tag caching fundamentally requires exploiting page-level metadata locality to ensure efficient use of the 3-D DRAM bandwidth. Plain sub-blocking exploits this locality but incurs holes in the cache (i.e., diminished DRAM cache capacity), whereas decoupled organizations avoid holes but destroy this locality. I propose Bandwidth-Efficient Tag Access (BETA) DRAM cache (β$ ) which avoids holes while exploiting the locality through various metadata organizational techniques. Using simulations, I conclusively show that the primary concern in DRAM caches is bandwidth and not latency, and that due to β$\u27s tag bandwidth efficiency, β$ with a T$performs 15$

TimeTrader: Exploiting Latency Tail to Save Datacenter Energy for On-line Data-Intensive Applications

Datacenters running on-line, data-intensive applications (OLDIs) consume significant amounts of energy. However, reducing their energy is challenging due to their tight response time requirements. A key aspect of OLDIs is that each user query goes to all or many of the nodes in the cluster, so that the overall time budget is dictated by the tail of the replies' latency distribution; replies see latency variations both in the network and compute. Previous work proposes to achieve load-proportional energy by slowing down the computation at lower datacenter loads based directly on response times (i.e., at lower loads, the proposal exploits the average slack in the time budget provisioned for the peak load). In contrast, we propose TimeTrader to reduce energy by exploiting the latency slack in the sub- critical replies which arrive before the deadline (e.g., 80% of replies are 3-4x faster than the tail). This slack is present at all loads and subsumes the previous work's load-related slack. While the previous work shifts the leaves' response time distribution to consume the slack at lower loads, TimeTrader reshapes the distribution at all loads by slowing down individual sub-critical nodes without increasing missed deadlines. TimeTrader exploits slack in both the network and compute budgets. Further, TimeTrader leverages Earliest Deadline First scheduling to largely decouple critical requests from the queuing delays of sub- critical requests which can then be slowed down without hurting critical requests. A combination of real-system measurements and at-scale simulations shows that without adding to missed deadlines, TimeTrader saves 15-19% and 41-49% energy at 90% and 30% loading, respectively, in a datacenter with 512 nodes, whereas previous work saves 0% and 31-37%.Comment: 13 page

Rise of Blood Borne Infections in Pakistan. Is It a Call for Action?

These types of articles do not need abstracts

Perception of Individual Consumers toward Islamic Banking Products and Services in Pakistan

Islamic banking system was established in Pakistan since 1980. Now, the Islamic banking products are available to serve the customers but these products are not fully accepted by the customers due to the lack of marketing efforts by the providers. To identify the perception about Islamic banking system researcher fill the questionnaires from respondents that what they think about Islamic banking system. And, these respondents are the customers who hold bank account in conventional or Islamic bank. We analyze data through descriptive analysis to find the results about perception of Islamic banking. This study explores the perception of persons that responsible in financial affairs and this study were usage of Islamic banking facilities and respondents understanding of Islamic banking system on different aspects and to selection criteria of bank. Keywords: Consumer Perception, Islamic Banking system, Consumer awareness, features of Islamic ban

Are BP readings taken after a patient-physician encounter in a real-world clinic scenario the lowest of all the readings in a clinic visit.

Objective: To determine the difference in Blood Pressure (BP) readings taken before, during and after the clinic encounter. Study Design: Descriptive study. Place and Duration of Study: Cardiology Clinic, The Aga Khan University Hospital, Karachi, from January to August 2013. Methodology: Hypertensive and normotensive participants aged ≥ 18 years were recruited. Pre-clinic BP was measured by a nurse and in-clinic BP by a physician. After 15 minutes, two post-clinic BP readings were taken at 1 minute interval. All readings were taken using Omron HEM7221-E. Results: Out of 180 participants, males were 57% and 130 (71%) were hypertensive. Mean SBP (Systolic BP) taken preclinic, in-clinic, post-clinic 1 and post-clinic 2 were: 126 ± 20 mmHg, 131 ± 23 mmHg, 126 ± 20 mmHg and 121 ± 21 mmHg respectively (p \u3c 0.001). Mean DBP (Diastolic BP) taken pre-clinic, in-clinic, post-clinic 1 and post-clinic 2 were 77 ± 12 mmHg, 81 ± 13 mmHg, 79 ± 12 mmHg and 79 ± 11 mmHg respectively (p \u3c 0.001). Conclusion: BP taken in the post-clinic setting may significantly be the lowest reading in a clinic encounter, making in-clinic BP unreliable to diagnose or manage hypertension

Defining the hemodynamic response of hypertensive and normotensive subjects through serial timed blood pressure readings in the clinic

Background: Every third patient in the clinic is misdiagnosed due to white-coat phenomenon, necessitating needless and costly treatment. We aimed to study the hemodynamic response of the physician\u27s visit on hypertensive and normotensive patients by investigating the trend of blood pressure (BP) before, during and 15 min after the physician-patient encounter.Methods: A descriptive, cross-sectional study was conducted over a period of 8 months in the cardiology clinics at the Aga Khan University Hospital, Karachi. Both hypertensive and normotensive patients, aged ≥18 years, were recruited. Pregnant females or those with a history of volume loss were excluded. BP readings were taken using an automated, validated device (Omron-HEM7221-E) at three points: pre-clinic BP by the assessment nurse, in-clinic BP by the attending physician and post-clinic BP 15-min after the physician-patient encounter by a research assistant. Independent samples t-test was used to calculate the statistical difference between hypertensive and normotensive BP values.Results: Of 180 participants, 71% (n = 128) were hypertensive and 57% (n = 103) of all were males. The mean age of the participants was 57 ± 15 years. The mean and standard deviation(±SD) systolic BP (SBP) taken pre-clinic, in-clinic and 15-min post-clinic for hypertensive population was 128.7 ± 20 mmHg, 137.1 ± 21 mmHg and 127.9 ± 19 mmHg. The mean and standard deviation(±SD) SBP taken pre-clinic, in-clinic and 15 min post-clinic for normotensive population was 112 ± 16 mmHg, 115.8 ± 20 mmHg and 111.8 ± 15 mmHg. The hypertensive SBP values showed statistically significant difference from the normotensive values (difference in pre-clinic SBP: 16.7 mmHg, p-value \u3c 0.001; in-clinic SBP: 21.3 mmHg, p-value \u3c 0.001; and 15 min post-clinic: 16.1 mmHg, p-value \u3c 0.001).Conclusions: Hypertensive and normotensive patients display congruent hemodynamics upon visiting the physician, the alert response being accentuated amongst the hypertensive group. In-clinic BP readings are higher for both hypertensive and normotensive patients making them unreliable for screening and management of hypertension amongst both the groups

Inclusive Agricultural Growth in Pakistan— Understanding Some Basic Constraints

Inclusive agricultural growth is important for overall economic growth and particularly critical for rural socio-economic stability and poverty reduction in Pakistan. The majority of Pakistan‘s population and 44 percent of the overall labour force are dependent upon agriculture which only accounts for a little over 20 percent of national GDP. The paper highlights some basic constraints that have not been explicitly addressed in the policy research and implementation and have impeded inclusive agriculture growth. A descriptive analysis based on data from the Agriculture Census of Pakistan and the Pakistan Household Income and Economic Survey—both of which were conducted in 2010-11—is used to show how high levels of poverty and its disparity across regions, combined with the declining size of operated holdings and associated fragmentation especially in the smallest size categories which now form over 60 percent of the agricultural holdings in Pakistan, are fundamental constraints. Poverty is both the result as well as the consequence of fragmented markets, weak institutions including governance; and, inadequate policy research and implementation. A better research based policy understanding of some basic constraints, and the variations across regions in such factors such as the declining size and fragmentation of operated farms, rural poverty; and, the levels of market development and institutions is essential along with effective implementation. One size fits all policies have not and will not work. JEL Classification: O40, Q15, I32, P46 Keywords: Inclusive Growth, Land Holding, Land Tenure, Income Distribution, Povert

A retrospective study on use of palliative care for patients with alcohol related end stage liver disease in United States

BACKGROUND: Palliative care (PC) has been shown to be beneficial in end stage liver disease (ESLD), yet the hospitalization data for PC utilization is unknown. AIM: To identify the trend of PC utilization for the special population of alcohol-associated ESLD patients, factors affecting its use and ascertain its impact on healthcare utilization. METHODS: We analyzed around 78 million discharges from the 2007-2014 national inpatient sample and 2010-2014 national readmission database including adult patients admitted for decompensated alcohol-associated cirrhosis. We identified patients with PC consultation as a secondary diagnosis. Odds ratios (OR) and means were adjusted for confounders using multivariate regression analysis models. RESULTS: Out of the total 1421849 hospitalizations for decompensated liver cirrhosis, 62782 (4.4%) hospitalizations had a PC consult, which increased from 0.8% (1258) of all alcohol-associated ESLD hospitalizations in 2007 to 6.6% in 2014 ( CONCLUSION: Inpatient PC is sparingly used for patients with decompensated alcohol related liver disease, however it has increased over the past decade. PC consultation is associated with lower 30-d readmission rates on multivariate analysis, and lower hospitalization cost and length of stay in patients with ACLF score ≥ 2

The Post Clinic Ambulatory Blood Pressure (PC-ABP) study correlates Post Clinic Blood Pressure (PCBP) with the gold standard Ambulatory Blood Pressure

Objectives: Our previous study showed that post-clinic blood pressure (BP) taken 15 min after a physician-patient encounter was the lowest reading in a routine clinic. We aimed to validate this reading with 24 h Ambulatory Blood Pressure Monitoring (ABPM) readings. A cross-sectional study was conducted in the cardiology clinics at the Aga Khan University, Pakistan. Hypertensive patients aged ≥ 18 years, or those referred for the diagnosis of hypertension were included.Results: Of 150 participants, 49% were males. 76% of all participants were hypertensive. Pre-clinic BP reading was measured by a nurse, in-clinic by a physician and 15 min post-clinic by a research assistant using a validated, automated BP device (Omron-HEM7221-E). All patients were referred for 24 h ABPM. Among the three readings taken during a clinic visit, mean (± SD) systolic BP (SBP) pre-clinic, in-clinic, and 15 min post-clinic were 153.2 ± 23, 152.3 ± 21, and 140.0 ± 18 mmHg, respectively. Mean (± SD) diastolic BP (DBP) taken pre-clinic, in-clinic and 15 min post-clinic were 83.5 ± 12, 90.9 ± 12, and 86.4 ± 11 mmHg respectively. Mean (± SD) daytime ambulatory SBP, DBP and pulse readings were 134.7 ± 15, 78.7 ± 15 mmHg, and 72.6 ± 12/min, respectively. Pearson correlation coefficients of pre-clinic, in-clinic and post-clinic SBP with daytime ambulatory-SBP were 0.4 (p value: \u3c 0.001), 0.5 (p value: \u3c 0.001) and 0.6 (p value: \u3c 0.001), respectively. Post-clinic BP has a good correlation with ambulatory BP and may be considered a more reliable reading in the clinic setting