3 research outputs found
Patterns of Economic Growth and Poverty in Sudan
This paper reviewing the economic growth in real terms and have overlook to poverty levels and incidence in Sudan. However, more focus is given to per capita income, since the relation is always observed between poverty levels and per capita income growth. Furthermore, the sectoral contribution to GDP growth also reviewed, to see where income concentrates did? And what was the effect on poverty situation? Sudan was expected to achieve high rates of growth after independence due to vast and rich agricultural land, considerable livestock component as well as capable human resources. However, that do not realized for greatest part of the last five decades. After, enjoying moderate rates of growth and economic stability till 1975, Sudan began to enter into deep structural problems. Sudan’s GDP grew at a trend rate of 2 % while the population was growing at around 2.8 % per annum. This has resulted in reducing the real per capita GDP by 11 % over the fourteen years period affecting the poverty situation in the whole country. Meanwhile, the causes of rural poverty in Sudan are to be found in the sustained urban bias of the development strategies adopted since independence. This tended to neglect the traditional agricultural sector where the vast majority of population lives and is the main source of rural livelihood. This has resulted in high rural to urban migration unaccompanied by either increased productivity in the sector or sufficient urban development to generate the necessary urban employment opportunities, which led to urban poverty in return. Keywords: poverty, rural-urban, inequality, deprivation
Janus: Intra-Process Isolation for High-Throughput Data Plane Libraries
As network, I/O, accelerator, and NVM devices capable of a million operations per second make their way into data centers, the software stack managing such devices has been shifting from implementations within the operating system kernel to more specialized kernel-bypass approaches. While the in-kernel approach guarantees both safety and fairness, it imposes too much overhead on microsecond-scale tasks. Kernel-bypass approaches improve throughput substantially but sacrifice safety and complicate resource management: if applications are mutually untrusting, then either each application must have exclusive access to its own device or else the device itself must implement resource management.
This paper shows how to attain both safety and performance via intra-process isolation for multiple data plane libraries. Our protected libraries provide separate user-level protection domains for different services (e.g., network and in-memory database), with performance approaching that of unprotected kernel bypass. We explore two concrete implementations of protected libraries. The first uses Intel's VM functions (VMFUNC) mechanism to switch between pre-established address spaces without entering the kernel. The second uses the mechanism of memory protection keys (Intel's PKU) to change the permissions associated with subsets of a single address space.
We show that these approaches can efficiently protect high-throughput in-memory databases and user-space network stacks. The PKU approach incurs less than 10% protection cost at up to 2.3 million library switches per second per core. The VMFUNC approach is more expensive, but, it eliminates the need to inspect program binaries and offers stronger protection against speculative side-channel data leaks. Both approaches significantly outperform kernel-level protection or system call switching of user-level address spaces