{"id":104635,"date":"2022-07-12T09:36:46","date_gmt":"2022-07-12T07:36:46","guid":{"rendered":"https:\/\/prohoster.info\/blog\/novosti-interneta\/dlya-yadra-linux-predlozhena-realizacziya-funkczii-memchr-rabotayushhaya-do-4-raz-bystree"},"modified":"2022-07-12T09:36:46","modified_gmt":"2022-07-12T07:36:46","slug":"dlya-yadra-linux-predlozhena-realizacziya-funkczii-memchr-rabotayushhaya-do-4-raz-bystree","status":"publish","type":"post","link":"https:\/\/prohoster.info\/pl\/blog\/news\/dlya-yadra-linux-predlozhena-realizacziya-funkczii-memchr-rabotayushhaya-do-4-raz-bystree","title":{"rendered":"Dla j\u0105dra Linux zaproponowano implementacj\u0119 funkcji memchr, dzia\u0142aj\u0105c\u0105 do 4 razy szybciej","gt_translate_keys":[{"key":"rendered","format":"text"}]},"content":{"rendered":"
A set of patches has been proposed for inclusion in the Linux kernel with an optimized implementation of the memchr() function, used for finding a character in an array. Unlike the old version, which used byte-by-byte comparison, the proposed implementation is built with the full utilization of 64- and 32-bit CPU registers. Instead of bytes, comparison is performed using machine words, allowing for at least 4 bytes to be compared at a time. <\/p>\n
When searching in large strings, the new version turned out to be about 4 times faster than the old one (for example, for strings of 1000 characters). For small strings, the efficiency of the new implementation isn't as significant, but it is still higher compared to the original version. In the Linux kernel, the size of strings processed in memchr() reaches 512 bytes. The performance gain for 512-byte strings, in situations where the searched character is located at the end of the string, is 20%. <\/p>\n
Testowanie j\u0105dra 5.18 z now\u0105 wersj\u0105 \u201ememchr()\u201d dla architektur 32- i 64-bitowych nie ujawni\u0142o \u017cadnych problem\u00f3w. Ca\u0142kowity wzrost wydajno\u015bci podsystem\u00f3w j\u0105dra przy u\u017cyciu zoptymalizowanej wersji \u201ememchr()\u201d nie zosta\u0142 jeszcze oceniony, podobnie jak celowo\u015b\u0107 zast\u0105pienia implementacji (w kodzie j\u0105dra wywo\u0142anie funkcji memchr() wyst\u0119puje 129 razy, w tym w kodach sterownik\u00f3w i system\u00f3w plik\u00f3w). \n \u0179r\u00f3d\u0142o: opennet.ru<\/a> <\/p>","protected":false,"gt_translate_keys":[{"key":"rendered","format":"html"}]},"excerpt":{"rendered":"