1 #!/bin/sh /etc/rc.common
5 EXTRA_COMMANDS
="compact status"
6 EXTRA_HELP
=" compact trigger compaction for all Z-RAM swap dev's
7 status print out status information & statistics about Z-RAM swap devices"
13 while read line
; do case "$line" in MemTotal
:*) set $line; echo "$2"; break ;; esac; done </proc
/meminfo
16 zram_getsize
() # in megabytes
18 local zram_size
="$( uci -q get system.@system[0].zram_size_mb )"
19 local ram_size
="$( ram_getsize )"
21 if [ -z "$zram_size" ]; then
22 # e.g. 6mb for 16mb-routers or 61mb for 128mb-routers
23 echo $
(( ram_size
/ 2048 ))
33 [ -e "$zram_dev" ] ||
{
34 logger
-s -t zram_applicable
-p daemon.crit
"[ERROR] device '$zram_dev' not found"
38 command -v mkswap
>/dev
/null ||
{
39 logger
-s -t zram_applicable
-p daemon.err
"[ERROR] 'mkswap' not installed"
43 command -v swapon
>/dev
/null ||
{
44 logger
-s -t zram_applicable
-p daemon.err
"[ERROR] 'swapon' not installed"
48 command -v swapoff
>/dev
/null ||
{
49 logger
-s -t zram_applicable
-p daemon.err
"[ERROR] 'swapoff' not installed"
57 echo "/dev/zram${idx:-0}"
64 local proc_entry
="/sys/block/$( basename "$dev" )/reset"
66 logger
-s -t zram_reset
-p daemon.debug
"$message via $proc_entry"
67 echo "1" >"$proc_entry"
72 #get unallocated zram dev
73 local zdev
=$
( zram_dev
)
75 if [ "$(mount | grep $zdev)" ]; then
76 local idx
=$
(cat /sys
/class
/zram-control
/hot_add
)
77 zdev
="$( zram_dev $idx )"
86 local zram_comp_algo
="$( uci -q get system.@system[0].zram_comp_algo )"
88 if [ -z "$zram_comp_algo" ]; then
89 # lzo-rle fails on small RAM devices, default to lzo, which is always available
93 if [ $
(grep -c "$zram_comp_algo" /sys
/block
/$
( basename $dev )/comp_algorithm
) -ne 0 ]; then
94 logger
-s -t zram_comp_algo
-p daemon.debug
"Set compression algorithm '$zram_comp_algo' for zram '$dev'"
95 echo $zram_comp_algo > "/sys/block/$( basename $dev )/comp_algorithm"
97 logger
-s -t zram_comp_algo
-p daemon.debug
"Compression algorithm '$zram_comp_algo' is not supported for '$dev'"
104 local logical_cpus
=$
( grep -ci "^processor" /proc
/cpuinfo
)
105 [ $logical_cpus -gt 1 ] ||
return 1
106 local zram_comp_streams
="$( uci -q get system.@system[0].zram_comp_streams )"
107 [ -n "$zram_comp_streams" ] && [ "$zram_comp_streams" -le "$logical_cpus" ] || zram_comp_streams
=$logical_cpus
108 if [ -e /sys
/block
/$
( basename $dev )/max_comp_streams
]; then
109 logger
-s -t zram_comp_streams
-p daemon.debug
"Set max compression streams to '$zram_comp_streams' for zram '$dev'"
110 echo $zram_comp_streams > /sys
/block
/$
( basename $dev )/max_comp_streams
114 #print various stats info about zram swap device
117 local zdev
="/sys/block/$( basename "$1" )"
119 printf "\nGathering stats info for zram device \"$( basename "$1" )\"\n\n"
121 printf "Z-RAM\n-----\n"
122 printf "%-25s - %s\n" "Block device" $zdev
123 awk '{ printf "%-25s - %d MiB\n", "Device size", $1/1024/1024 }' <$zdev/disksize
124 printf "%-25s - %s\n" "Compression algo" "$(cat $zdev/comp_algorithm)"
125 printf "%-25s - %s\n" "Compression streams" "$( cat $zdev/max_comp_streams)"
127 awk 'BEGIN { fmt = "%-25s - %.2f %s\n"
128 fmt2 = "%-25s - %d\n"
129 print "\nDATA\n----" }
130 { printf fmt, "Original data size", $1/1024/1024, "MiB"
131 printf fmt, "Compressed data size", $2/1024/1024, "MiB"
132 printf fmt, "Compress ratio", $1/$2, ""
133 print "\nMEMORY\n------"
134 printf fmt, "Memory used, total", $3/1024/1024, "MiB"
135 printf fmt, "Allocator overhead", ($3-$2)/1024/1024, "MiB"
136 printf fmt, "Allocator efficiency", $2/$3*100, "%"
137 printf fmt, "Maximum memory ever used", $5/1024/1024, "MiB"
138 printf fmt, "Memory limit", $4/1024/1024, "MiB"
139 print "\nPAGES\n-----"
140 printf fmt2, "Same pages count", $6
141 printf fmt2, "Pages compacted", $7 }' <$zdev/mm_stat
143 awk '{ printf "%-25s - %d\n", "Free pages discarded", $4 }' <$zdev/io_stat
148 # compact zram device (reduce memory allocation overhead)
149 local zdev
="/sys/block/$( basename "$1" )"
151 local old_mem_used
=$
(awk '{print $3}' <$zdev/mm_stat
)
152 local old_overhead
=$
(awk '{print $3-$2}' <$zdev/mm_stat
)
154 echo 1 > $zdev/compact
156 # If not running interactively, than just return
157 [ -z "$PS1" ] && return 0
160 echo "Compacting zram device $zdev"
161 awk -v old_mem
="$old_mem_used" -v ovr
="$old_overhead" 'BEGIN { fmt = "%-25s - %.1f %s\n" }
162 { printf fmt, "Memory usage reduced by ", (old_mem-$3)/1024/1024, "MiB"
163 printf fmt, "Overhead reduced by", (ovr-($3-$2))/ovr*100, "%" }' <$zdev/mm_stat
168 if [ $
( grep -cs zram
/proc
/swaps
) -ne 0 ]; then
169 logger
-s -t zram_start
-p daemon.notice
"[OK] zram swap is already mounted"
173 local zram_size
="$( zram_getsize )"
174 local zram_dev
="$( zram_getdev )"
175 zram_applicable
"$zram_dev" ||
return 1
176 local zram_priority
="$( uci -q get system.@system[0].zram_priority )"
177 zram_priority
=${zram_priority:+-p $zram_priority}
179 logger
-s -t zram_start
-p daemon.debug
"activating '$zram_dev' for swapping ($zram_size MegaBytes)"
181 zram_reset
"$zram_dev" "enforcing defaults"
182 zram_comp_algo
"$zram_dev"
183 zram_comp_streams
"$zram_dev"
184 echo $
(( $zram_size * 1024 * 1024 )) >"/sys/block/$( basename "$zram_dev" )/disksize"
186 swapon
-d $zram_priority "$zram_dev"
193 for zram_dev
in $
( grep zram
/proc
/swaps |
awk '{print $1}' ); do {
194 logger
-s -t zram_stop
-p daemon.debug
"deactivate swap $zram_dev"
195 swapoff
"$zram_dev" && zram_reset
"$zram_dev" "claiming memory back"
196 local dev_index
="$( echo $zram_dev | grep -o "[0-9]*$
" )"
197 if [ $dev_index -ne 0 ]; then
198 logger
-s -t zram_stop
-p daemon.debug
"removing zram $zram_dev"
199 echo $dev_index > /sys
/class
/zram-control
/hot_remove
204 # show memory stats for all zram swaps
207 for zram_dev
in $
( grep zram
/proc
/swaps |
awk '{print $1}' ); do {
208 zram_stats
"$zram_dev"
212 # trigger compaction for all zram swaps
215 for zram_dev
in $
( grep zram
/proc
/swaps |
awk '{print $1}' ); do {
216 zram_compact
"$zram_dev"