bzr branch
http://darksoft.org/webbzr/perf/perftools
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by Suren A. Chilingaryan
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#define _XOPEN_SOURCE 500
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#include <stdio.h> |
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#include <stdlib.h> |
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#include <unistd.h> |
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#include <errno.h> |
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#include <sys/mman.h> |
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#include <sys/sysinfo.h> |
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// 8 bytes page tables + 64 bytes mem map
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// However may be mem_map (struct page) is already excluded?
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#define BYTES_PER_PAGE 8
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int main(int argc, char *argv[]) { |
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int err; |
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size_t size; |
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void *buf; |
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FILE *f; |
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struct sysinfo info; |
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if (argc < 2) { |
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printf("Usage: %s [+]<GB>\n", argv[0]); |
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printf(" + : lock this amount of memory\n"); |
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printf(" = : total memory after lock\n"); |
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printf(" - : free memory after lock [default]\n"); |
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exit(0); |
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}
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f = fopen("/proc/sys/vm/drop_caches", "w"); |
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if (!f) { |
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printf("Failed to drop caches...\n"); |
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exit(-1); |
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}
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fprintf(f, "3\n"); |
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fclose(f); |
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err = sysinfo(&info); |
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if (err) { |
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printf("sysinfo failed with errno: %i\n", errno); |
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exit(-1); |
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}
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if ((argv[1][0] < '0')||(argv[1][0] > '9')) |
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size = atol(argv[1]+1) * 1024 * 1024 * 1024; |
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else
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size = atol(argv[1]) * 1024 * 1024 * 1024; |
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if (argv[1][0]=='+') { |
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} else if (argv[1][0]=='=') { |
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size_t page_size = getpagesize(); |
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size_t pages; |
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size_t page_tables; |
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pages = (info.totalram * info.mem_unit) / page_size; |
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page_tables = pages * BYTES_PER_PAGE; |
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printf("Detected %zu units of memory, unit size %u\n", info.totalram, info.mem_unit); |
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printf("Expected size of page tables: %zu MB, \n", page_tables / 1024 / 1024); |
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printf("Leaving aside %zu bytes\n", size); |
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if (info.totalram * info.mem_unit < size) { |
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printf("Requested more memory (%zu GB) when available (%zu GB)\n", size / 1024 / 1024 / 1024, info.totalram * info.mem_unit / 1024 / 1024 / 1024); |
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exit(-1); |
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}
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size = info.totalram * info.mem_unit - size - page_tables; |
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} else { |
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if (info.freeram*info.mem_unit < size) { |
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printf("Requested more memory (%zu GB) when is currently free (%zu GB)\n", size / 1024 / 1024 / 1024, info.freeram * info.mem_unit / 1024 / 1024 / 1024); |
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exit(-1); |
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}
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size = info.freeram * info.mem_unit - size; |
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}
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if (!size) exit(0); |
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printf("Trying to get %zu bytes\n", size); |
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buf = malloc(size); |
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if (!buf) { |
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printf("Allocation failed\n"); |
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exit(-1); |
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}
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err = mlock(buf, size); |
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if (err) { |
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printf("Locking memory failed, errno: %i\n", errno); |
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exit(-1); |
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}
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printf("Locked %zu GB memory\n", size/1024/1024/1024); |
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while (1) sleep(60); |
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}
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