56 lines
1.4 KiB
C
56 lines
1.4 KiB
C
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/*
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* butterfly.c
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*
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* Created on: Sep 9, 2011
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* Author: sears
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*/
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#include <config.h>
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#include <stasis/common.h>
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#include <stasis/util/time.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <assert.h>
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int main(int argc, char * argv[]) {
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if(argc != 4) {
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printf("usage: %s filename file_size sector_size\n", argv[0]); fflush(stdout); abort();
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}
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const char * filename = argv[1];
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uint64_t file_size = atoll(argv[2]);
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int sector_size = atoi(argv[3]);
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int fd = -1;
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fd = open(filename, O_WRONLY|O_DSYNC); //|O_DIRECT);
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struct timeval start, stop;
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void * buf;
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posix_memalign(&buf, sector_size, sector_size);
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memset(buf, 0, sector_size);
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gettimeofday(&stop,0);
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for(uint64_t i = 0; i < file_size/sector_size; i++) {
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int err = pwrite(fd, buf, sector_size, 0);
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if(err == -1) {
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perror("Couldn't write");
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abort();
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}
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assert(err && err == sector_size);
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gettimeofday(&start, 0);
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double reset_elapsed = stasis_timeval_to_double(stasis_subtract_timeval(start,stop));
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err = pwrite(fd, buf, sector_size, i * sector_size);
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if(err == -1) {
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perror("Couldn't write");
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abort();
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}
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assert(err && err == sector_size);
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gettimeofday(&stop, 0);
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double elapsed = stasis_timeval_to_double(stasis_subtract_timeval(stop,start));
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printf("%lld\t%0.5f\t%0.5f\n", (long long) i, elapsed, reset_elapsed);
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}
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close(fd);
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}
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