1 #!/bin/sh /etc/rc.common
5 extra_command
"compact" "Trigger compaction for all Z-RAM swap dev's"
6 extra_command
"status" "Print out information & statistics about Z-RAM swap devices"
12 while read line
; do case "$line" in MemTotal
:*) set $line; echo "$2"; break ;; esac; done </proc
/meminfo
15 zram_getsize
() # in megabytes
17 local zram_size
="$( uci -q get system.@system[0].zram_size_mb )"
18 local ram_size
="$( ram_getsize )"
20 if [ -z "$zram_size" ]; then
21 # e.g. 6mb for 16mb-routers or 61mb for 128mb-routers
22 echo $
(( ram_size
/ 2048 ))
32 [ -e "$zram_dev" ] ||
{
33 logger
-s -t zram_applicable
-p daemon.crit
"[ERROR] device '$zram_dev' not found"
37 [ -x /sbin
/mkswap
] ||
{
38 logger
-s -t zram_applicable
-p daemon.err
"[ERROR] 'BusyBox mkswap' not installed"
42 [ -x /sbin
/swapon
] ||
{
43 logger
-s -t zram_applicable
-p daemon.err
"[ERROR] 'BusyBox swapon' not installed"
47 [ -x /sbin
/swapoff
] ||
{
48 logger
-s -t zram_applicable
-p daemon.err
"[ERROR] 'BusyBox swapoff' not installed"
56 echo "/dev/zram${idx:-0}"
63 local proc_entry
="/sys/block/$( basename "$dev" )/reset"
65 logger
-s -t zram_reset
-p daemon.debug
"$message via $proc_entry"
66 echo "1" >"$proc_entry"
71 #get unallocated zram dev
72 local zdev
=$
( zram_dev
)
74 if [ "$(mount | grep $zdev)" ]; then
75 local idx
=$
(cat /sys
/class
/zram-control
/hot_add
)
76 zdev
="$( zram_dev $idx )"
85 local zram_comp_algo
="$( uci -q get system.@system[0].zram_comp_algo )"
87 if [ -z "$zram_comp_algo" ]; then
88 # lzo-rle fails on small RAM devices, default to lzo, which is always available
92 if [ $
(grep -c "$zram_comp_algo" /sys
/block
/$
( basename $dev )/comp_algorithm
) -ne 0 ]; then
93 logger
-s -t zram_comp_algo
-p daemon.debug
"Set compression algorithm '$zram_comp_algo' for zram '$dev'"
94 echo $zram_comp_algo > "/sys/block/$( basename $dev )/comp_algorithm"
96 logger
-s -t zram_comp_algo
-p daemon.debug
"Compression algorithm '$zram_comp_algo' is not supported for '$dev'"
100 #print various stats info about zram swap device
103 local zdev
="/sys/block/$( basename "$1" )"
105 printf "\nGathering stats info for zram device \"$( basename "$1" )\"\n\n"
107 printf "Z-RAM\n-----\n"
108 printf "%-25s - %s\n" "Block device" $zdev
109 awk '{ printf "%-25s - %d MiB\n", "Device size", $1/1024/1024 }' <$zdev/disksize
110 printf "%-25s - %s\n" "Compression algo" "$(cat $zdev/comp_algorithm)"
112 awk 'BEGIN { fmt = "%-25s - %.2f %s\n"
113 fmt2 = "%-25s - %d\n"
114 print "\nDATA\n----" }
115 { printf fmt, "Original data size", $1/1024/1024, "MiB"
116 printf fmt, "Compressed data size", $2/1024/1024, "MiB"
117 printf fmt, "Compress ratio", $1/$2, ""
118 print "\nMEMORY\n------"
119 printf fmt, "Memory used, total", $3/1024/1024, "MiB"
120 printf fmt, "Allocator overhead", ($3-$2)/1024/1024, "MiB"
121 printf fmt, "Allocator efficiency", $2/$3*100, "%"
122 printf fmt, "Maximum memory ever used", $5/1024/1024, "MiB"
123 printf fmt, "Memory limit", $4/1024/1024, "MiB"
124 print "\nPAGES\n-----"
125 printf fmt2, "Same pages count", $6
126 printf fmt2, "Pages compacted", $7 }' <$zdev/mm_stat
128 awk '{ printf "%-25s - %d\n", "Free pages discarded", $4 }' <$zdev/io_stat
133 # compact zram device (reduce memory allocation overhead)
134 local zdev
="/sys/block/$( basename "$1" )"
136 local old_mem_used
=$
(awk '{print $3}' <$zdev/mm_stat
)
137 local old_overhead
=$
(awk '{print $3-$2}' <$zdev/mm_stat
)
139 echo 1 > $zdev/compact
141 # If not running interactively, than just return
142 [ -z "$PS1" ] && return 0
145 echo "Compacting zram device $zdev"
146 awk -v old_mem
="$old_mem_used" -v ovr
="$old_overhead" 'BEGIN { fmt = "%-25s - %.1f %s\n" }
147 { printf fmt, "Memory usage reduced by ", (old_mem-$3)/1024/1024, "MiB"
148 printf fmt, "Overhead reduced by", (ovr-($3-$2))/ovr*100, "%" }' <$zdev/mm_stat
153 if [ $
( grep -cs zram
/proc
/swaps
) -ne 0 ]; then
154 logger
-s -t zram_start
-p daemon.notice
"[OK] zram swap is already mounted"
158 local zram_size
="$( zram_getsize )"
159 local zram_dev
="$( zram_getdev )"
160 zram_applicable
"$zram_dev" ||
return 1
161 local zram_priority
="$( uci -q get system.@system[0].zram_priority )"
162 zram_priority
=${zram_priority:+-p $zram_priority}
164 logger
-s -t zram_start
-p daemon.debug
"activating '$zram_dev' for swapping ($zram_size MegaBytes)"
166 zram_reset
"$zram_dev" "enforcing defaults"
167 zram_comp_algo
"$zram_dev"
168 echo $
(( $zram_size * 1024 * 1024 )) >"/sys/block/$( basename "$zram_dev" )/disksize"
169 /sbin
/mkswap
"$zram_dev"
170 /sbin
/swapon
-d $zram_priority "$zram_dev"
177 for zram_dev
in $
( grep zram
/proc
/swaps |
awk '{print $1}' ); do {
178 logger
-s -t zram_stop
-p daemon.debug
"deactivate swap $zram_dev"
179 /sbin
/swapoff
"$zram_dev" && zram_reset
"$zram_dev" "claiming memory back"
180 local dev_index
="$( echo $zram_dev | grep -o "[0-9]*$
" )"
181 if [ $dev_index -ne 0 ]; then
182 logger
-s -t zram_stop
-p daemon.debug
"removing zram $zram_dev"
183 echo $dev_index > /sys
/class
/zram-control
/hot_remove
188 # show memory stats for all zram swaps
191 for zram_dev
in $
( grep zram
/proc
/swaps |
awk '{print $1}' ); do {
192 zram_stats
"$zram_dev"
196 # trigger compaction for all zram swaps
199 for zram_dev
in $
( grep zram
/proc
/swaps |
awk '{print $1}' ); do {
200 zram_compact
"$zram_dev"