Use mlock2() instead of mlock() on Linux and use mlockall(MCL_FUTURE). #98
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agowa
reviewed
Mar 2, 2024
vmtouch.c
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| printf(" -t touch pages into memory\n"); | ||
| printf(" -e evict pages from memory\n"); | ||
| printf(" -l lock pages in physical memory with mlock(2)\n"); | ||
| printf(" -l lock pages in physical memory with mlock(2) or mlock2(2)\n"); |
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How about using ifndef her too? that way the usage help would clearly show which one it is using.
Use mlock2() instead of mlock() on Linux:
- mlock2() allows a third argument MLOCK_ONFAULT, which allow to
lock the pages in a range before touching them, so mlock2()
can be called before touching all pages instead of after.
- "vmtouch -t -l" some_file would not keep the pages in cache
after touching them, so at the lock() step they needed to
be read again from disk. After this patch files are cached
twice as fast on this system.
Use mlockall(MCL_FUTURE) instead of mlockall(MCL_CURRENT):
- Set mlockall(MCL_FUTURE) before touching pages to have similar
behaviour as the mlock2() approach above.
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Use mlock2() instead of mlock() on Linux:
lock the pages in a range before touching them, so mlock2()
can be called before touching all pages instead of after.
after touching them, so at the lock() step they needed to
be read again from disk. After this patch files are cached
twice as fast on this system.
Use mlockall(MCL_FUTURE) instead of mlockall(MCL_CURRENT):
behaviour as the mlock2() approach above.