{ pkgs, lib, config, ... }:
with lib;
{
zramSwap = {
  enable = true;
  algorithm = mkDefault "zstd";
  # There is little point creating a zram greater
  # than twice the size of memory.
  memoryPercent = mkDefault 150;
  # Linux supports multithreaded compression for 1 device since 3.15.
  # See https://lkml.org/lkml/2014/2/28/404 for details.
  swapDevices = mkDefault 1;
};

boot.kernel.sysctl = {
  # Increase cache pressure, which increases the tendency of the kernel to
  # reclaim memory used for caching of directory and inode objects. You will use
  # less memory over a longer period of time. The performance hit is negated by
  # the downside of swapping sooner.
  "vm.vfs_cache_pressure" = mkDefault 500;

  # Increasing how aggressively the kernel will swap memory pages since we are
  # using ZRAM first.
  "vm.swappiness" = mkDefault 100;

  # Background processes will start writing right away when it hits the 1% limit
  "vm.dirty_background_ratio" = mkDefault 1;

  # The system won’t force synchronous I/O until it gets to 50% dirty_ratio.
  "vm.dirty_ratio" = mkDefault 50;
};
}