4 ms·

tl;dr - If you're running a database, or generally memory intensive system, while also using multiple CPUs you should run this command: echo 0 > /proc/sys/vm/zo

• finnh 15y ago
  Except that's not the TL;DR at all. From the article: "An aside on zone_reclaim_mode The zone_reclaim_mode tunable in /proc/sys/vm can be used to fine-tune memory reclamation policies in a NUMA system. Subject to some clarifications from the linux-mm mailing list, it doesn’t seem to help in this case." The real TL;DR is "run your mysql command under the auspices of '/usr/bin/numactl --interleave all' so that your big pool allocation is split evenly across nodes" And an even better solution would be if _only_ the big pool allocation use interleaved allocation, and all the rest used normal node-bound allocation. This would require some sort of change to the malloc calls though, yes? All of the solutions listed in the article operate at the granularity of a process (or higher), not down to the individual allocation.
  • j2labs 15y ago
    My mistake, you are correct that I forgot the second command. The new tldr is: numactl --interleave=all /path/to/daemon; echo 0 > /proc/sys/vm/zone_reclaim_mode This file helps explain the different ways one can tweak memory with Linux: http://www.kernel.org/doc/Documentation/sysctl/vm.txt http://www.kernel.org/doc/Documentation/sysctl/vm.txt