ea9b55680e8f2856168a464049f7bdb1caa51b75
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 ))
31 echo "/dev/zram${idx:-0}"
38 local proc_entry
="/sys/block/$( basename "$dev" )/reset"
40 logger
-s -t zram_reset
-p daemon.debug
"$message via $proc_entry"
41 echo "1" >"$proc_entry"
46 #get unallocated zram dev
47 local zdev
=$
( zram_dev
)
49 if [ "$(mount | grep $zdev)" ]; then
50 local idx
=$
(cat /sys
/class
/zram-control
/hot_add
)
51 zdev
="$( zram_dev $idx )"
60 local zram_comp_algo
="$( uci -q get system.@system[0].zram_comp_algo )"
62 if [ -z "$zram_comp_algo" ]; then
63 # lzo-rle fails on small RAM devices, default to lzo, which is always available
67 if [ $
(grep -c "$zram_comp_algo" /sys
/block
/$
( basename $dev )/comp_algorithm
) -ne 0 ]; then
68 logger
-s -t zram_comp_algo
-p daemon.debug
"Set compression algorithm '$zram_comp_algo' for zram '$dev'"
69 echo $zram_comp_algo > "/sys/block/$( basename $dev )/comp_algorithm"
71 logger
-s -t zram_comp_algo
-p daemon.debug
"Compression algorithm '$zram_comp_algo' is not supported for '$dev'"
75 #print various stats info about zram swap device
78 local zdev
="/sys/block/$( basename "$1" )"
80 printf "\nGathering stats info for zram device \"$( basename "$1" )\"\n\n"
82 printf "Z-RAM\n-----\n"
83 printf "%-25s - %s\n" "Block device" $zdev
84 awk '{ printf "%-25s - %d MiB\n", "Device size", $1/1024/1024 }' <$zdev/disksize
85 printf "%-25s - %s\n" "Compression algo" "$(cat $zdev/comp_algorithm)"
87 awk 'BEGIN { fmt = "%-25s - %.2f %s\n"
89 print "\nDATA\n----" }
90 { printf fmt, "Original data size", $1/1024/1024, "MiB"
91 printf fmt, "Compressed data size", $2/1024/1024, "MiB"
92 printf fmt, "Compress ratio", $1/$2, ""
93 print "\nMEMORY\n------"
94 printf fmt, "Memory used, total", $3/1024/1024, "MiB"
95 printf fmt, "Allocator overhead", ($3-$2)/1024/1024, "MiB"
96 printf fmt, "Allocator efficiency", $2/$3*100, "%"
97 printf fmt, "Maximum memory ever used", $5/1024/1024, "MiB"
98 printf fmt, "Memory limit", $4/1024/1024, "MiB"
99 print "\nPAGES\n-----"
100 printf fmt2, "Same pages count", $6
101 printf fmt2, "Pages compacted", $7 }' <$zdev/mm_stat
103 awk '{ printf "%-25s - %d\n", "Free pages discarded", $4 }' <$zdev/io_stat
108 # compact zram device (reduce memory allocation overhead)
109 local zdev
="/sys/block/$( basename "$1" )"
111 local old_mem_used
=$
(awk '{print $3}' <$zdev/mm_stat
)
112 local old_overhead
=$
(awk '{print $3-$2}' <$zdev/mm_stat
)
114 echo 1 > $zdev/compact
116 # If not running interactively, than just return
117 [ -z "$PS1" ] && return 0
120 echo "Compacting zram device $zdev"
121 awk -v old_mem
="$old_mem_used" -v ovr
="$old_overhead" 'BEGIN { fmt = "%-25s - %.1f %s\n" }
122 { printf fmt, "Memory usage reduced by ", (old_mem-$3)/1024/1024, "MiB"
123 printf fmt, "Overhead reduced by", (ovr-($3-$2))/ovr*100, "%" }' <$zdev/mm_stat
128 [ -e /proc
/swaps
] ||
{
129 logger
-s -t zram_start
-p daemon.crit
"kernel doesn't support swap"
133 if [ $
( grep -cs zram
/proc
/swaps
) -ne 0 ]; then
134 logger
-s -t zram_start
-p daemon.notice
"[OK] zram swap is already mounted"
138 local zram_dev
="$( zram_getdev )"
140 [ -e "$zram_dev" ] ||
{
141 logger
-s -t zram_start
-p daemon.crit
"[ERROR] device '$zram_dev' not found"
145 local zram_size
="$( zram_getsize )"
146 local zram_priority
="$( uci -q get system.@system[0].zram_priority )"
148 if [ -z "$zram_priority" ]; then
152 logger
-s -t zram_start
-p daemon.debug
"activating '$zram_dev' for swapping ($zram_size MegaBytes)"
154 zram_reset
"$zram_dev" "enforcing defaults"
155 zram_comp_algo
"$zram_dev"
156 echo $
(( $zram_size * 1024 * 1024 )) >"/sys/block/$( basename "$zram_dev" )/disksize"
157 busybox mkswap
"$zram_dev"
158 busybox swapon
-d -p $zram_priority "$zram_dev"
165 for zram_dev
in $
( grep zram
/proc
/swaps |
awk '{print $1}' ); do {
166 logger
-s -t zram_stop
-p daemon.debug
"deactivate swap $zram_dev"
167 busybox swapoff
"$zram_dev" && zram_reset
"$zram_dev" "claiming memory back"
168 local dev_index
="$( echo $zram_dev | grep -o "[0-9]*$
" )"
169 if [ $dev_index -ne 0 ]; then
170 logger
-s -t zram_stop
-p daemon.debug
"removing zram $zram_dev"
171 echo $dev_index > /sys
/class
/zram-control
/hot_remove
176 # show memory stats for all zram swaps
179 for zram_dev
in $
( grep zram
/proc
/swaps |
awk '{print $1}' ); do {
180 zram_stats
"$zram_dev"
184 # trigger compaction for all zram swaps
187 for zram_dev
in $
( grep zram
/proc
/swaps |
awk '{print $1}' ); do {
188 zram_compact
"$zram_dev"