cregit-Linux how code gets into the kernel

Release 4.18 tools/testing/selftests/vm/gup_benchmark.c

#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>

#include <sys/ioctl.h>
#include <sys/mman.h>
#include <sys/prctl.h>
#include <sys/stat.h>
#include <sys/types.h>

#include <linux/types.h>


#define MB (1UL << 20)

#define PAGE_SIZE sysconf(_SC_PAGESIZE)


#define GUP_FAST_BENCHMARK	_IOWR('g', 1, struct gup_benchmark)


struct gup_benchmark {
	
__u64 delta_usec;
	
__u64 addr;
	
__u64 size;
	
__u32 nr_pages_per_call;
	
__u32 flags;
};


int main(int argc, char **argv) { struct gup_benchmark gup; unsigned long size = 128 * MB; int i, fd, opt, nr_pages = 1, thp = -1, repeats = 1, write = 0; char *p; while ((opt = getopt(argc, argv, "m:r:n:tT")) != -1) { switch (opt) { case 'm': size = atoi(optarg) * MB; break; case 'r': repeats = atoi(optarg); break; case 'n': nr_pages = atoi(optarg); break; case 't': thp = 1; break; case 'T': thp = 0; break; case 'w': write = 1; default: return -1; } } gup.nr_pages_per_call = nr_pages; gup.flags = write; fd = open("/sys/kernel/debug/gup_benchmark", O_RDWR); if (fd == -1) perror("open"), exit(1); p = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_ANONYMOUS | MAP_PRIVATE, -1, 0); if (p == MAP_FAILED) perror("mmap"), exit(1); gup.addr = (unsigned long)p; if (thp == 1) madvise(p, size, MADV_HUGEPAGE); else if (thp == 0) madvise(p, size, MADV_NOHUGEPAGE); for (; (unsigned long)p < gup.addr + size; p += PAGE_SIZE) p[0] = 0; for (i = 0; i < repeats; i++) { gup.size = size; if (ioctl(fd, GUP_FAST_BENCHMARK, &gup)) perror("ioctl"), exit(1); printf("Time: %lld us", gup.delta_usec); if (gup.size != size) printf(", truncated (size: %lld)", gup.size); printf("\n"); } return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Kirill A. Shutemov362100.00%1100.00%
Total362100.00%1100.00%


Overall Contributors

PersonTokensPropCommitsCommitProp
Kirill A. Shutemov424100.00%1100.00%
Total424100.00%1100.00%
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