zram-swap: support swap priority

[oweals/openwrt.git] / package / system / zram-swap / files / zram.init

diff --git a/package/system/zram-swap/files/zram.init b/package/system/zram-swap/files/zram.init
index 2db986f9a8b8cf4ebd7cea2c5c8a569fd0d7697c..49140ad40658620c9fc6d757dacf3f21021151a0 100755 (executable)
--- a/package/system/zram-swap/files/zram.init
+++ b/package/system/zram-swap/files/zram.init
@@ -2,17 +2,21 @@
 
 START=15
 
-ram_size()
+EXTRA_COMMANDS="compact status"
+EXTRA_HELP="        compact trigger compaction for all Z-RAM swap dev's
+        status  print out status information & statistics about Z-RAM swap devices"
+
+ram_getsize()
 {
        local line
 
        while read line; do case "$line" in MemTotal:*) set $line; echo "$2"; break ;; esac; done </proc/meminfo
 }
 
-zram_size()    # in megabytes
+zram_getsize() # in megabytes
 {
        local zram_size="$( uci -q get system.@system[0].zram_size_mb )"
-       local ram_size="$( ram_size )"
+       local ram_size="$( ram_getsize )"
 
        if [ -z "$zram_size" ]; then
                # e.g. 6mb for 16mb-routers or 61mb for 128mb-routers
@@ -93,26 +97,92 @@ zram_comp_algo()
        fi
 }
 
-start()
+zram_comp_streams()
 {
-       local zram_size="$( zram_size )"
-       local zram_dev
+       local dev="$1"
+       local logical_cpus=$( grep -ci "^processor" /proc/cpuinfo )
+       [ $logical_cpus -gt 1 ] || return 1
+       local zram_comp_streams="$( uci -q get system.@system[0].zram_comp_streams )"
+       [ -n "$zram_comp_streams" ] && [ "$zram_comp_streams" -le "$logical_cpus" ] || zram_comp_streams=$logical_cpus
+       if [ -e /sys/block/$( basename $dev )/max_comp_streams ]; then
+               logger -s -t zram_comp_streams -p daemon.debug "Set max compression streams to '$zram_comp_streams' for zram '$dev'"
+               echo $zram_comp_streams > /sys/block/$( basename $dev )/max_comp_streams
+       fi
+}
+
+#print various stats info about zram swap device
+zram_stats()
+{
+       local zdev="/sys/block/$( basename "$1" )"
+
+       printf "\nGathering stats info for zram device \"$( basename "$1" )\"\n\n"
+
+       printf "Z-RAM\n-----\n"
+       printf "%-25s - %s\n" "Block device" $zdev
+       awk '{ printf "%-25s - %d MiB\n", "Device size", $1/1024/1024 }' <$zdev/disksize
+       printf "%-25s - %s\n" "Compression algo" "$(cat $zdev/comp_algorithm)"
+       printf "%-25s - %s\n" "Compression streams" "$( cat $zdev/max_comp_streams)"
+
+       awk 'BEGIN { fmt = "%-25s - %.2f %s\n"
+               fmt2 = "%-25s - %d\n"
+               print "\nDATA\n----" }
+               { printf fmt, "Original data size", $1/1024/1024, "MiB"
+               printf fmt, "Compressed data size", $2/1024/1024, "MiB"
+               printf fmt, "Compress ratio", $1/$2, ""
+               print "\nMEMORY\n------"
+               printf fmt, "Memory used, total", $3/1024/1024, "MiB"
+               printf fmt, "Allocator overhead", ($3-$2)/1024/1024, "MiB"
+               printf fmt, "Allocator efficiency", $2/$3*100, "%"
+               printf fmt, "Maximum memory ever used", $5/1024/1024, "MiB"
+               printf fmt, "Memory limit", $4/1024/1024, "MiB"
+               print "\nPAGES\n-----"
+               printf fmt2, "Same pages count", $6
+               printf fmt2, "Pages compacted", $7 }' <$zdev/mm_stat
+
+       awk '{ printf "%-25s - %d\n", "Free pages discarded", $4 }' <$zdev/io_stat
+}
+
+zram_compact()
+{
+       # compact zram device (reduce memory allocation overhead)
+       local zdev="/sys/block/$( basename "$1" )"
+
+       local old_mem_used=`awk '{print $3}' <$zdev/mm_stat`
+       local old_overhead=`awk '{print $3-$2}' <$zdev/mm_stat`
+
+       echo 1 > $zdev/compact
+
+       # If not running interactively, than just return
+       [ -z "$PS1" ] && return 0
 
+       echo ""
+       echo "Compacting zram device $zdev"
+       awk -v old_mem="$old_mem_used" -v ovr="$old_overhead" 'BEGIN { fmt = "%-25s - %.1f %s\n" }
+               { printf fmt, "Memory usage reduced by ", (old_mem-$3)/1024/1024, "MiB"
+               printf fmt, "Overhead reduced by", (ovr-($3-$2))/ovr*100, "%" }' <$zdev/mm_stat
+}
+
+start()
+{
        if [ $( grep -cs zram /proc/swaps ) -ne 0 ]; then
                logger -s -t zram_start -p daemon.notice "[OK] zram swap is already mounted"
                return 1
        fi
 
-       zram_dev="$( zram_getdev )"
+       local zram_size="$( zram_getsize )"
+       local zram_dev="$( zram_getdev )"
        zram_applicable "$zram_dev" || return 1
+       local zram_priority="$( uci -q get system.@system[0].zram_priority )"
+       zram_priority=${zram_priority:+-p $zram_priority}
 
        logger -s -t zram_start -p daemon.debug "activating '$zram_dev' for swapping ($zram_size MegaBytes)"
 
        zram_reset "$zram_dev" "enforcing defaults"
        zram_comp_algo "$zram_dev"
+       zram_comp_streams "$zram_dev"
        echo $(( $zram_size * 1024 * 1024 )) >"/sys/block/$( basename "$zram_dev" )/disksize"
        mkswap "$zram_dev"
-       swapon "$zram_dev"
+       swapon $zram_priority "$zram_dev"
 }
 
 stop()
@@ -130,3 +200,18 @@ stop()
        } done
 }
 
+# show memory stats for all zram swaps
+status()
+{
+       for zram_dev in $( grep zram /proc/swaps |awk '{print $1}' ); do {
+               zram_stats "$zram_dev"
+       } done
+}
+
+# trigger compaction for all zram swaps
+compact()
+{
+       for zram_dev in $( grep zram /proc/swaps |awk '{print $1}' ); do {
+               zram_compact "$zram_dev"
+       } done
+}