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June 27, 2018 16:56
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| #!/bin/sh | |
| # -*- mode:shell-script sh-basic-offset:4 indent-tabs-mode:nil -*- | |
| ######################################################################################################################## | |
| # zswap.sh - Activate and tune Zswap compressed cache for swap pages. | |
| # | |
| # Enables/Renables/tunes zswap without the need for initramfs/dracut/modprobe/modules-load hackery. | |
| # | |
| # Author : <REDACTED> | |
| # Copyright: 2018 <REDACTED> <########@####.com> | |
| # | |
| ######################################################################################################################## | |
| # Basic support for the Linux Standard Base Specification 3.1.0 | |
| ### BEGIN INIT INFO | |
| # Provides: zswap | |
| # Required-Start: | |
| # Required-Stop: | |
| # Default-Start: 2 3 4 5 | |
| # Default-Stop: 0 1 6 | |
| # Short-Description: Zswap | |
| # Description: Activate and tune Zswap compressed cache for swap pages | |
| ### END INIT INFO | |
| ######################################################################################################################## | |
| # TODO: a lot... | |
| # BUGS: probably a lot of typos. | |
| # "FEATURES": Does not run under /bin/sh -> /bin/dash (shebang change to /bin/bash required and removal of set +o posix) | |
| ######################################################################################################################## | |
| set +o posix | |
| if [ -z "$SHELLOPTS" ] || [[ "$SHELLOPTS" = *posix* ]]; then exit; fi | |
| ## | |
| # Tunables | |
| ## | |
| ZSWAP_COMPRESSOR="lz4hc" # Default: 20% if unset or invalid. | |
| ZSWAP_SIZE="40" # Default: lz4 if unset or invalid. | |
| # Set upstart $JOB for compatibility, and also for logger -t "${JOB}" | |
| JOB="ZSWAP" | |
| # shellcheck disable=SC2039 | |
| zswap__load_depmods() { | |
| __load_depmods__() | |
| { ## Probably unnecessary, but modprobe compressor/zpool before setting sysfs params. #; | |
| __load_depmods__load_compressor__() | |
| { ## Load optimal compressor and zpool modules if available and not already loaded #; | |
| __load_compressor__() | |
| { ## $ZSWAP_COMPRESSOR || lz4 || lzo #; | |
| local \ | |
| req_zswap_compressor \ | |
| kver 2>/dev/null || : | |
| req_zswap_compressor="${ZSWAP_COMPRESSOR}" 2>/dev/null || : | |
| kver="$(uname -r 2>/dev/null)" || : | |
| __load_compressor__lz4hc() | |
| { | |
| echo lz4hc >/sys/module/zswap/parameters/compressor >/dev/null 2>&1 || true | |
| if [[ "$(</sys/module/zswap/parameters/compressor)" = lz4hc && | |
| -e '/sys/module/lz4hc' | |
| ]] || | |
| [[ "$(</proc/modules)" = *'lz4hc '* || | |
| "$(</boot/config-"$kver")" = *'CONFIG_LZ4HC_COMPRESS=y'* || | |
| "$(zcat /proc/config.gz)" = *'CONFIG_LZ4HC_COMPRESS=y'* | |
| ]] 2>/dev/null; | |
| then | |
| return | |
| else | |
| if modprobe -q lz4hc; then | |
| return | |
| else | |
| logger -t "${JOB}" "WARNING: lz4hc compressor unavailable." | |
| return 1 | |
| fi | |
| fi | |
| } | |
| __load_compressor__lz4() | |
| { | |
| echo lz4 >/sys/module/zswap/parameters/compressor >/dev/null 2>&1 || true | |
| if [[ "$(</sys/module/zswap/parameters/compressor)" = lz4 && | |
| -e '/sys/module/lz4' | |
| ]] || | |
| [[ "$(</proc/modules)" = *'lz4 '* || | |
| "$(</boot/config-"$kver")" = *'CONFIG_LZ4_COMPRESS=y'* || | |
| "$(zcat /proc/config.gz)" = *'CONFIG_LZ4_COMPRESS=y'* | |
| ]] 2>/dev/null; | |
| then | |
| return | |
| else | |
| if modprobe -q lz4; then | |
| return | |
| else | |
| logger -t "${JOB}" "WARNING: lz4 compressor unavailable." | |
| return 1 | |
| fi | |
| fi | |
| } | |
| __load_compressor__lzo() | |
| { | |
| echo lzo >/sys/module/zswap/parameters/compressor >/dev/null 2>&1 || true | |
| if [[ "$(</sys/module/zswap/parameters/compressor)" = lzo && | |
| -e '/sys/module/lzo' | |
| ]] || | |
| [[ "$(</proc/modules)" = *'lzo '* || | |
| "$(</boot/config-"$kver")" = *'CONFIG_LZO_COMPRESS=y'* || | |
| "$(zcat /proc/config.gz)" = *'CONFIG_LZO_COMPRESS=y'* | |
| ]] 2>/dev/null; | |
| then | |
| return | |
| else | |
| if modprobe -q lzo; then | |
| return | |
| else ## Highly unlikely... #; | |
| logger -t "${JOB}" "ERROR: lzo appears missing!" | |
| return 1 | |
| fi | |
| fi | |
| } | |
| case "$req_zswap_compressor" in | |
| lz4hc) | |
| __load_compressor__lz4hc || | |
| __load_compressor__lz4 || | |
| __load_compressor__lzo || return 1 | |
| ;; | |
| lz4) | |
| __load_compressor__lz4 || | |
| __load_compressor__lzo || return 1 | |
| ;; | |
| lzo) | |
| __load_compressor__lzo || return 1 | |
| ;; | |
| esac | |
| return | |
| } | |
| __load_compressor__ || return 1 | |
| return | |
| } | |
| __load_depmods__load_compressor__ || return 1 | |
| return | |
| } | |
| __load_depmods__load_zpool__() | |
| { # shellcheck disable=SC2039 #; | |
| __load_zpool__() | |
| { | |
| __load_zpool__z3fold__() | |
| { | |
| echo z3fold >/sys/module/zswap/parameters/zpool >/dev/null 2>&1 || true | |
| if [[ "$(</sys/module/zswap/parameters/zpool)" = z3fold && | |
| -e '/sys/module/z3fold' | |
| ]] || | |
| [[ "$(</proc/modules)" = *'z3fold '* || | |
| "$(</boot/config-"$kver")" = *'CONFIG_Z3FOLD=y'* || | |
| "$(zcat /proc/config.gz)" = *'CONFIG_Z3FOLD=y'* | |
| ]] 2>/dev/null; | |
| then | |
| return | |
| else | |
| if modprobe -q z3fold; then | |
| logger -t "${JOB}" "z3fold loaded." | |
| return | |
| else ## Not fatal (yet). #; | |
| logger -t "${JOB}" "z3fold not available, falling back to zbud." | |
| modprobe -q zbud >/dev/null 2>&1 || : | |
| return 1 | |
| fi | |
| fi | |
| } | |
| __load_zpool__zbud() | |
| { | |
| echo z3fold >/sys/module/zswap/parameters/zpool >/dev/null 2>&1 || true | |
| if [[ "$(</sys/module/zswap/parameters/zpool)" = zbud && | |
| -e '/sys/module/zbud' | |
| ]] || | |
| [[ "$(</proc/modules)" = *'z3fold '* || | |
| "$(</boot/config-"$kver")" = *'CONFIG_ZBUD=y'* || | |
| "$(zcat /proc/config.gz)" = *'CONFIG_ZBUD=y'* | |
| ]] 2>/dev/null; | |
| then | |
| return | |
| fi | |
| modprobe -q zbud ## Else fallback to zbud, but be extra sure before we errror+exit. #; | |
| echo zbud >/sys/module/zswap/parameters/zpool >/dev/null 2>&1 || true | |
| if [[ "$(</sys/module/zswap/parameters/zpool)" = zbud && | |
| -e '/sys/module/zbud' | |
| ]] || | |
| [[ "$(</proc/modules)" = *'zbud '* || | |
| "$(zcat /proc/config.gz)" = *'CONFIG_ZBUD=y'* || | |
| "$(zcat /proc/config.gz)" = *'CONFIG_ZBUD=y'* | |
| ]] 2>/dev/null; | |
| then | |
| logger -t "${JOB}" "zbud loaded." | |
| return | |
| else | |
| logger -t "${JOB}" "Error: zbud not available," | |
| return 1 | |
| fi | |
| } | |
| __load_zpool__z3fold || __load_zpool__zbud || return 1 | |
| return | |
| } | |
| __load_depmods__load_compressor || return 1 | |
| __load_depmods__load_zpool || return 1 | |
| return | |
| } | |
| __load_depmods__ || return 1 | |
| return | |
| } | |
| # shellcheck disable=SC2039 | |
| zswap__load_module() { | |
| __load_module__() | |
| { ## Load zswap module with optimal zpool/compressor. #; | |
| ## Prefer z3fold over zbud while respecting value of $ZSWAP_COMPRESSOR #; | |
| local req_zswap_compressor 2>/dev/null || : | |
| req_zswap_compressor="${ZSWAP_COMPRESSOR}" | |
| __load_module__z3fold_lz4hc() { | |
| modprobe -q zswap zpool=z3fold compressor=lz4hc enabled=Y || return 1 | |
| return | |
| } | |
| __load_module__z3fold_lz4() { | |
| modprobe -q zswap zpool=z3fold compressor=lz4 enabled=Y || return 1 | |
| return | |
| } | |
| __load_module__z3fold_lzo() { | |
| modprobe -q zswap zpool=z3fold compressor=lzo enabled=Y || return 1 | |
| return | |
| } | |
| __load_module__zbud_lz4hc() { | |
| modprobe -q zswap zpool=zbud compressor=lz4hc enabled=Y || return 1 | |
| return | |
| } | |
| __load_module__zbud_lz4() { | |
| modprobe -q zswap zpool=zbud compressor=lz4 enabled=Y || return 1 | |
| return | |
| } | |
| __load_module__zbud_lzo() { | |
| modprobe -q zswap zpool=zbud compressor=lzo enabled=Y || return 1 | |
| return | |
| } | |
| case "$req_zswap_compressor" in | |
| lz4hc) | |
| __load_module__z3fold_lz4hc && return | |
| __load_module__zbud_lz4hc && return | |
| __load_module__z3fold_lz4 && return | |
| __load_module__zbud_lz4 && return | |
| __load_module__z3fold_lzo && return | |
| __load_module__zbud_lzo || return 1 | |
| ;; | |
| lz4) | |
| __load_module__z3fold_lz4 && return | |
| __load_module__zbud_lz4 && return | |
| __load_module__z3fold_lzo && return | |
| __load_module__zbud_lzo || return 1 | |
| ;; | |
| lzo) | |
| __load_module__z3fold_lzo && return | |
| __load_module__zbud_lzo || return 1 | |
| ;; | |
| esac | |
| return | |
| } | |
| __load_module__ || return 1 | |
| return | |
| } | |
| # shellcheck disable=SC2039 | |
| zswap__set_param() { | |
| __set_param__() | |
| { ## set sysfs parameters #; | |
| # Abort early if sysfs interface is not available. | |
| if [ ! -e "/sys/module/zswap/parameters" ]; then | |
| logger -t "${JOB}" "Error: /sys/module/zswap/parameters doesn't exist!"; | |
| return 1 | |
| fi | |
| local \ | |
| req_zswap_compressor \ | |
| max_pool_size 2>/dev/null || : | |
| req_zswap_compressor="${ZSWAP_COMPRESSOR}" | |
| max_pool_size="${ZSWAP_SIZE}" | |
| # | |
| # Note: These probably need a test at the end to make sure it was set correctly, | |
| # but return codes from sysfs writes to zswap are usually fairly accurate. | |
| # Note: A write to sysfs *should* autoload the module(s) even if not loaded, | |
| # but if the preferred module fails, we attempt to load the fallback modules anyway. | |
| # Note: `modprobe -q <module>` returns 0 if builtin or already loaded. | |
| # | |
| __set_param__set_comp__() # Compressors #; | |
| { ## Priority: $ZSWAP_COMPRESSOR={lz4hc?} || lz4 || lzo || fail #; | |
| __set_comp__() | |
| { | |
| __set_comp__lz4hc() | |
| { | |
| if echo lz4hc >/sys/module/zswap/parameters/compressor | |
| then | |
| logger -t "${JOB}" "Compressor set to lz4hc" | |
| return | |
| else ## Failing here isn't fatal (yet) #; | |
| logger -t "${JOB}" "Failed to set lz4hc compressor. Trying lz4 instead." | |
| modprobe -q lz4 >/dev/null 2>&1 | |
| return 1 | |
| fi | |
| } | |
| __set_comp__lz4() | |
| { | |
| if echo lz4 >/sys/module/zswap/parameters/compressor | |
| then | |
| logger -t "${JOB}" "Compressor set to lz4" | |
| return | |
| else | |
| logger -t "${JOB}" "Failed to set lz4 compressor. Trying lzo instead." | |
| return 1 | |
| fi | |
| } | |
| __set_comp__lzo() | |
| { | |
| if echo lzo >/sys/module/zswap/parameters/compressor | |
| then | |
| logger -t "${JOB}" "Compressor set to lzo" | |
| return | |
| else # Fatal if all 3 return non-zero. #; | |
| logger -t "${JOB}" "Failed to set lzo compressor, aborting." | |
| return 1 | |
| fi | |
| } | |
| case "$req_zswap_compressor" in | |
| lz4hc) | |
| __set_comp__lz4hc || | |
| __set_comp__lz4 || | |
| __set_comp__lzo || return 1 | |
| ;; | |
| lz4) | |
| __set_comp__lz4hc || | |
| __set_comp__lz4 || return 1 | |
| ;; | |
| lzo) | |
| __set_comp__lzo || return 1 | |
| ;; | |
| esac | |
| return | |
| } | |
| __set_comp__ || return 1 | |
| return | |
| } | |
| __set_param__set_zpool__() | |
| { ## Priority: z3fold || zbud || fail #; | |
| __set_zpool__() | |
| { | |
| __set_zpool__z3fold() | |
| { ## Failing here isn't fatal (yet). #; | |
| if echo z3fold >/sys/module/zswap/parameters/zpool | |
| then | |
| logger -t "${JOB}" "Zpool set to z3fold." | |
| return | |
| else | |
| logger -t "${JOB}" "Failed to set Zpool to z3fold, trying zbud." | |
| modprobe -q zbud >/dev/null 2>&1 || : | |
| return 1 | |
| fi | |
| } | |
| __set_zpool__zbud() | |
| { ## Fatal if neither load. #; | |
| if echo zbud >/sys/module/zswap/parameters/zpool | |
| then | |
| logger -t "${JOB}" "Zpool set to zbud." | |
| return | |
| else | |
| logger -t "${JOB}" "Error: Failed to Zpool to zbud, aborting." | |
| return 1 | |
| fi | |
| } | |
| __set_zpool__z3fold || | |
| __set_zpool__zbud || return 1 | |
| return | |
| } | |
| __set_zpool__ || return 1 | |
| return | |
| } | |
| __set_param__set_max_pool_size__() | |
| { | |
| __set_max_pool_size__() | |
| { ## $ZSWAP_SIZE || 20% #; | |
| __set_max_pool_size__req_size() | |
| { | |
| if [ -n "$max_pool_size" ] | |
| then | |
| if echo "$max_pool_size" >/sys/module/zswap/parameters/max_pool_percent | |
| then | |
| if [[ "$(</sys/module/zswap/parameters/max_pool_percent)" = "$max_pool_size" ]] | |
| then | |
| logger -t "${JOB}" "max_pool_size set to ${max_pool_size}." | |
| return | |
| else | |
| logger -t "${JOB}" "Failed to set max_pool_size to ${max_pool_size}, trying default 20%" | |
| return 1 | |
| fi | |
| fi | |
| fi | |
| } | |
| __set_max_pool_size__default() | |
| { ## Else use fallback value of 20% #; | |
| if echo 20 >/sys/module/zswap/parameters/max_pool_percent | |
| then | |
| if [[ "$(</sys/module/zswap/parameters/max_pool_percent)" = "20" ]] | |
| then | |
| logger -t "${JOB}" "max_pool_size set to 20%." | |
| return | |
| else ## Fatal if neither are successfully set #; | |
| "${JOB}" "Failed to set max_pool_size, aborting." | |
| return 1 | |
| fi | |
| fi | |
| } | |
| __set_max_pool_size__req_size || | |
| __set_max_pool_size__default || return 1 | |
| return 0 | |
| } | |
| __set_max_pool_size__ || return 1 | |
| return 0 | |
| } | |
| __set_param__set_comp__ || return 1 | |
| __set_param__set_zpool__ || return 1 | |
| __set_param__set_max_pool_size__ || return 1 | |
| logger -t "${JOB}" "Zswap parameters successfully set."; | |
| return | |
| } | |
| __set_param__ || return 1 | |
| return | |
| } | |
| # shellcheck disable=SC2039 #; | |
| zswap__start() { | |
| if [ "$EUID" != 0 ] || [ "$UID" != 0 ]; then | |
| echo 'Error: Must be root to start/stop.' >&2 | |
| return 1 | |
| fi | |
| __start__() | |
| { | |
| __start__reset_reload() | |
| { | |
| if [[ "$(</sys/module/zswap/parameters/enabled)" = "Y" ]]; then | |
| echo N >/sys/module/zswap/parameters/enabled | |
| fi | |
| # If the cache is large, it may take time to decompress back to main memory, | |
| # so try several times. It isn't fatal if this fails, however. | |
| local tries=0 | |
| while [ ${tries} -le 6 ]; do ## wait up to 3 seconds | |
| modprobe -rq zswap 2>/dev/null && break | |
| : $(( tries += 1 )) | |
| sleep 0.5 | |
| done | |
| # (Re)load module with best available options (or requested options). | |
| zswap__load_depmods || return 1 | |
| zswap__load_module || return 1 | |
| return | |
| } | |
| __start__reset_setparam() | |
| { ## Note: `gzip -cd /proc/config.gz | /bin/grep -sq 'CONFIG_ZSWAP=y'` is a tiny bit faster, #; | |
| ## but makes the code more unreadable. (zgrep is slower however). | |
| if [[ -e '/sys/module/zswap' || | |
| "$(</proc/modules)" = *'zswap '* || | |
| "$(</boot/config-"$kver")" = *'CONFIG_ZSWAP=y'* || | |
| "$(zcat /proc/config.gz)" = *'CONFIG_ZSWAP=y'* | |
| ]] 2>/dev/null; | |
| then ## just load compressor and zpool if builtin #; | |
| zswap__load_depmods || return 1 | |
| if [[ "$(</sys/module/zswap/parameters/enabled)" = "Y" ]]; then | |
| echo N >/sys/module/zswap/parameters/enabled | |
| fi | |
| # Set our sysfs parameters and enable zswap again. | |
| zswap__set_param || return 1 | |
| echo Y >/sys/module/zswap/parameters/enabled || return 1 | |
| return | |
| fi | |
| } | |
| if [[ "$(</proc/modules)" = *'zswap '* ]]; then | |
| __start__reset_reload || return 1 | |
| fi | |
| __start__reset_setparam || return 1 | |
| return | |
| } | |
| logger -t "${JOB}" "Starting Zswap compressed swap cache..." | |
| __start__ || { logger -t "${JOB}" "Failed to start Zswap compressed swap cache"; return 1; } | |
| logger -t "${JOB}" "Started Zswap compressed swap cache." | |
| return | |
| } | |
| # shellcheck disable=SC2039 | |
| zswap__stop() { | |
| if [ "$EUID" != 0 ] || [ "$UID" != 0 ]; then | |
| echo 'Error: Must be root to start/stop' >&2 | |
| return 1 | |
| fi | |
| logger -t "${JOB}" "Stopping Zswap compressed swap cache..." | |
| if [[ "$(</sys/module/zswap/parameters/enabled)" = "Y" ]]; then | |
| echo N >/sys/module/zswap/parameters/enabled | |
| fi | |
| if [[ "$(</proc/modules)" = *'zswap '* ]]; then | |
| local tries=0 | |
| while [ ${tries} -le 10 ]; do ## wait up to 5 seconds to unload. | |
| modprobe -rq zswap 2>/dev/null && break | |
| : $(( tries += 1 )) | |
| sleep 0.5 | |
| done | |
| fi | |
| if [[ ! -e /sys/module/zswap || "$(</proc/modules)" != *'zswap '* ]] || | |
| [[ "$(</sys/module/zswap/parameters/enabled)" = "N" ]] 2>/dev/null; | |
| then | |
| logger -t "${JOB}" "Stopped Zswap compressed swap cache." | |
| return | |
| else | |
| logger -t "${JOB}" "Failed to stop Zswap compressed swap cache." | |
| return 1 | |
| fi | |
| } | |
| # shellcheck disable=SC2035,SC2039 | |
| zswap__status() { ## STATUS: Spam various zswap settings. #; | |
| # Show general swap info first. | |
| printf '\n==== Swap block devs ==== \n\n' | |
| if [ -x /sbin/swapon ]; then | |
| /sbin/swapon 2>/dev/null | |
| elif [ -x /usr/sbin/swapon ]; then | |
| /usr/sbin/swapon 2>/dev/null | |
| fi | |
| local zdir fdir mdir 2>/dev/null || : | |
| zdir="/sys/kernel/debug/zswap" | |
| fdir="/sys/kernel/debug/frontswap" | |
| mdir="/sys/module/zswap/parameters" | |
| printf '\n==== Zswap Stats ==== \n\n' | |
| # Spam Zswap module parameters | |
| if [ -r "${mdir}" ]; then | |
| printf '%s:\n' "${mdir}" | |
| cd "${mdir}" || return 1 | |
| grep -s --color=auto '^' * || : | |
| else | |
| printf '\nZswap module not loaded.\n' | |
| return | |
| fi | |
| # Spam Zswap/Frontswap debug stats | |
| if [ -r "${zdir}" ] && [ -r "${fdir}" ]; then | |
| printf '%s:\n' "${fdir}" | |
| cd "${fdir}" || return 1 | |
| grep -s --color=auto '^' * || : | |
| printf '%s:\n' "${zdir}" | |
| cd "${zdir}" || return 1 | |
| grep -s --color=auto '^' * || : | |
| else | |
| if [ "$UID" = 0 ] || [ "$EUID" = 0 ]; then | |
| printf '\nDebugfs not mounted. Zswap/frontswap stats unavailable.\n\n' | |
| else | |
| printf '\ncannot access '/sys/kernel/debug/zswap/': Permission denied\n' | |
| printf 'cannot access '/sys/kernel/debug/frontswap/': Permission denied\n\n' | |
| fi | |
| fi | |
| } | |
| zswap__usage() { ## Usage & exit #; | |
| cat <<EOF | |
| Usage: $0 <start|stop|status> | |
| Start, stop, or show the status of compressed swap cache. | |
| EOF | |
| exit "$1" | |
| } | |
| # shellcheck disable=SC2039 | |
| zswap__main() | |
| { # MAIN #; | |
| set -e | |
| [ -z "$ZSWAP_SIZE" ] && ZSWAP_SIZE="25" | |
| [ -z "$ZSWAP_COMPRESSOR" ] && ZSWAP_COMPRESSOR="lz4" | |
| if [ $# -lt 1 ]; then ## If we're called without any argument, just start it by default. #; | |
| zswap__start || return 1 | |
| elif [ $# -gt 1 ]; then ## If we're called with more than one argument, return usage and exit. #; | |
| zswap__usage 1 | |
| else | |
| local cmd 2>/dev/null || : | |
| cmd="$1" | |
| shift | |
| case "${cmd}" in ## If given argument, ensure it's one we can handle. #; | |
| start) cmd="zswap__start" ;; | |
| stop) cmd="zswap__stop" ;; | |
| status) cmd="zswap__status" ;; | |
| *) usage 1 | |
| ;; | |
| esac | |
| ${cmd} "$@" || return 1 ## Call the func directly if valid. #; | |
| fi | |
| return | |
| } | |
| zswap__main "$@" || exit 1 | |
| ######################################################################################################################## | |
| # | |
| # ex: ft=sh sw=4 ts=4 sts=4 ai et | |
| # End of zswap | |
| # | |
| ######################################################################################################################## |
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