orangejulius
/ testWriteAmplification.c
Created
November 29, 2012 08:16
C program to write 4096 bytes starting at a random 512b sector, with sector offset passed in from the command line. Try it with your 4K sector hard drive (or SSD): non zero offsets will significantly reduce performance. Use only on an empty disk
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| #include <unistd.h> | |
| #include <stdio.h> | |
| #include <fcntl.h> | |
| char buffer[4096]; | |
| int main(int argc, char *argv[]) | |
| { | |
| int fd, i, off; | |
| long bk, byte; |
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| #include <stdio.h> | |
| #include <string.h> | |
| void* my_memcpy(void* destination, void* source, size_t num) | |
| { | |
| int i; | |
| char* d = destination; | |
| char* s = source; | |
| for (i = 0; i < num; i++) { | |
| d[i] = s[i]; |
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| all: mystrlen strlen | |
| mystrlen: mystrlen.c makestrs.h | |
| gcc -O2 mystrlen.c -o mystrlen | |
| strlen: strlen.c makestrs.h | |
| gcc -O2 strlen.c -o strlen | |
| clean: | |
| rm mystrlen strlen | |
| test: mystrlen strlen | |
| time ./mystrlen > /dev/null | |
| time ./strlen > /dev/null |
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