Memory: THP, zramswap, zswap, etc

##### THP #####
# https://access.redhat.com/solutions/46111
# echo never > /sys/kernel/mm/transparent_hugepage/enabled
echo madvise > /sys/kernel/mm/transparent_hugepage/enabled
echo never > /sys/kernel/mm/transparent_hugepage/defrag

/etc/default/grub:
GRUB_CMDLINE_LINUX_DEFAULT="transparent_hugepage=madvise"

update-grub
reboot

##### check which processes are using THP #####
awk  '/AnonHugePages/ { if($2>4){print FILENAME " " $0; system("ps -fp " gensub(/.*\/([0-9]+).*/, "\\1", "g", FILENAME))}}' /proc/*/smaps

##### zramswap #####
# https://interface31.ru/tech_it/2023/02/uluchshaem-proizvoditelnost-linux-pri-pomoshhi-zram.html
apt install zram-tools

/etc/default/zramswap:
ALGO=zstd
PERCENT=60
# SIZE=2048
PRIORITY=100

systemctl restart zramswap

/etc/sysctl.conf:
vm.swappiness=160

zramctl --output-all

##### zswap #####
# http://stupin.su/blog/zswap/
/etc/initramfs-tools/modules:
lz4
lz4_compress

update-initramfs -u -k all

/etc/default/grub:
GRUB_CMDLINE_LINUX_DEFAULT="zswap.enabled=1 zswap.compressor=lz4 zswap.max_pool_percent=80"

update-grub
reboot