On Linux performance of CPU-bound processes in the presence of network I/O
No Thumbnail Available
Date
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Saudi Digital Library
Abstract
ﺍﻟﺪﺭﺍﺳﺔ ﺍﳌﻘﺪﻣﺔ ﰲ ﻫﺬﺍ ﺍﻟﺒﺤﺚ ﺗﺴﻠﻂ ﺍﻟﻀﻮﺀ ﻋﻠﻰ ﺇﻣﻜﺎﻧﻴﺔ ﺣﺪﻭﺙ ﺗﺮﺍﺟﻊ ﺷﺪﻳﺪ ﰲ ﺃﺩﺍﺀ ﺍﻟﻌﻤﻠﻴﺎﺕ ﺍﳌﺮﺗﺒﻄﺔ ﺑﻮﺣﺪﺓ ﺍﳌﻌﺎﳉﺔ ﺍﳌﺮﻛﺰﻳﺔ ﻟﻠﺤﺎﺳﺐ ﰲ ﻧﻈﺎﻡ ﺗﺸﻐﻴﻞ ﻟﻴﻨﻮﻛﺲ، ﰲ ﻇﻞ ﺗﻮﺍﺟﺪ ﻋﻤﻠﻴﺎﺕ ﻣﺮﺗﺒﻄﺔ ﲟﻌﺎﳉﺔ ﺑﻴﺎﻧﺎﺕ ﺍﻟﺸﺒﻜﺔ .ﺍﳌﺪﻫﺶ ﺃﻥ ﺍﻟﺘﺮﺍﺟﻊ ﺍﻟﺸﺪﻳﺪ ﰲ ﺃﺩﺍﺀ ﺍﻟﻌﻤﻠﻴﺎﺕ ﺍﳌﺮﺗﺒﻄﺔ ﺑﻮﺣﺪﺓ ﺍﳌﻌﺎﳉﺔ ﺍﳌﺮﻛﺰﻳﺔ ﻻ ﳛﺪﺙ ﺇﻻ ﰲ ﳎﺎﻝ ﳏﺪﺩ ﻣﻦ ﺣﺮﻛﺔ ﺳﲑ ﺑﻴﺎﻧﺎﺕ ﺍﻟﺸﺒﻜﺔ، ﺑﻴﻨﻤﺎ ﻻ ﻳﻼﺣﻆ ﻫﺬﺍ ﺍﻟﺘﺮﺍﺟﻊ ﺧﺎﺭﺝ ﻫﺬﺍ ﺍ ﻟﻨﻄﺎﻕ ﻣﻦ ﺣﺮﻛﺔ ﺳﲑ ﺑﻴﺎﻧﺎﺕ ﺍﻟﺸﺒﻜﺔ .ﻗﻤﻨﺎ ﰲ ﻫﺬﺍ ﺍﻟﺒﺤﺚ ﺑﺈﺛﺒﺎﺕ ﻭﺟﻮﺩ ﻫﺬﻩ ﺍﻟﻈﺎﻫﺮﺓ ﻋﻤﻠﻴﺎ ﰲ ﻇﻞ ﻭﺟﻮﺩ ﺗﻄﺒﻴﻘﺎﺕ ﺷﺒﻜﻴﺔ ﳐﺘﻠﻔﺔ، ﻭ ﺑﺎﺳﺘﺨﺪﺍﻡ ﺃﺷﻜﺎﻝ ﻣﺘﻌﺪﺩﺓ ﻣﻦ ﺇﻋﺪﺍﺩﺍﺕ ﻧﻈﺎﻡ ﺍﻟﺘﺸﻐﻴﻞ ﻭ ﺍﻟﺸﺒﻜﺔ .ﺑﺎﻹﺿﺎﻓﺔ ﳌﺎ ﺳﺒﻖ،ﻟﻘﺪ ﰎ ﺇﺛﺒﺎﺕ ﻭﺟﻮﺩ ﻫﺬﻩ ﺍﻟﻈﺎﻫﺮﺓ ﰲ ﺇﺻﺪﺍﺭﻳﻦ ﳐﺘﻠﻔﲔ ﻣﻦ ﻧﻈﺎﻡ ﺍﳉﺪﻭﻟﺔ ﰲ ﻭﻧﻈﺎﻡ ﺍﳉﺪﻭﻟﺔ ﺍﻷﺣﺪﺙ، ﺍﳌﻌﺮﻭﻑ ﺑـﻨﻈﺎﻡ ﺍﳉﺪﻭﻟﺔ ﺫﻱ O(1) 2.6 ﻟﻴﻨﻮﻛﺲ، ﻭ ﳘﺎ :ﻧﻈﺎﻡ ﺍﳉﺪﻭﻟﺔ ﺍﳌﻌﺮﻭﻑ ﺑـ .ﻗﻤﻨﺎ ﺑﺘﻌﺪﻳﻞ ﺑﺮﳎﺔ ﻧﻈﺎﻡ ﻟﻴﻨﻮﻛﺲ ﻟﻠﻮﻗﻮﻑ ﺃﻛﺜﺮ ﻋﻠﻰ ﺍﳌﺸﻜﻠﺔ ﻭ ﲢﻠﻴﻞ ﺍﻟﺴﺒﺐ ﺍﻟﺮﺋﻴﺴﻲ ﻭﺭﺍﺀ (CFS) ﺍﻟﻌﺪﺍﻟﺔ ﺍﻟﻜﺎﻣﻠﺔ ﻫﺬﻩ ﺍﻟﻈﺎﻫﺮﺓ ﺍﻟﻐﺮﻳﺒﺔ .ﻟﻌﻼﺝ ﻫﺬﻩ ﺍﻟﻈﺎﻫﺮﺓ، ﰎ ﺍﻗﺘﺮﺍﺡ ﻭﺗﻄﺒﻴﻖ ﺣﻞ ﳑﻜﻦ ﻟﻜﻞ ﻣﻦ ﺍﻟﻨﺴﺨﺘﲔ ﻣﻦ ﻧﻈﺎﻡ ﺟﺪﻭﻟﺔ ﻟﻴﻨﻮﻛﺲ . ﻭﺿﺤﻨﺎ ﻋﻤﻠﻴﺎ ﻛﻴﻒ ﺃﻥ ﺍﳊﻞ ﺍﳌﻘﺘﺮﺡ ﻓﻌﺎﻝ ﺟﺪﺍ ﰲ ﲢﺴﲔ ﺃﺩﺍﺀ ﺍﻟﻌﻤﻠﻴﺎﺕ ﺍﳌﺮﺗﺒﻄﺔ ﺑﻮﺣﺪﺓ ﺍﳌﻌﺎﳉﺔ ﺍﳌﺮﻛﺰﻳﺔ ﻟﻠﺤﺎﺳﺐ ﰲ ﺑﻴﺌﺔ ﻧﻈﺎﻡ ﺗﺸﻐﻴﻞ ﻟﻴﻨﻮﻛﺲ ﺃﺣﺎﺩﻳﺔ ﻭ ﻣﺘﻌﺪﺩﺓ ﺍﳌﻌﺎﳉﺔ .ﻧﺘﺎﺋﺞ ﺍﻟﺘﺠﺎﺭﺏ ﺗﺜﺒﺖ ﺃﻳﻀﺎ ﻋﺪﻡ ﻭﺟﻮﺩ ﺃﻱ ﺗﺄﺛﲑ ﺳﻠﱯ ﻟﻠﺤﻞ ﺍﳌﻘﺘﺮﺡ ﻋﻠﻰ ﺃﺩﺍﺀ ﻋﻤﻠﻴﺎﺕ ﺍﻟﺸﺒﻜﺔ.