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zram-swap: Add zram compaction and statistics info output

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Executing '/etc/init.d/zram start' during runtime (with a swap being already
mounted) triggers zram device compaction and prints out nice stats info about
zram memory usage

Signed-off-by: Emil Muratov <gpm@hotplug.ru>
Signed-off-by: Christian Lamparter <chunkeey@gmail.com> [use IEC's MiB unit]
This commit is contained in:
Emil Muratov 2018-11-01 00:16:58 +03:00 committed by Christian Lamparter
parent c0d93432f2
commit b062c90f47
2 changed files with 58 additions and 2 deletions
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2
package/system/zram-swap/Makefile
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@ -9,7 +9,7 @@ include $(TOPDIR)/rules.mk
PKG_NAME:=zram-swap
PKG_VERSION:=1.1
PKG_RELEASE:=2
PKG_RELEASE:=3
PKG_BUILD_DIR := $(BUILD_DIR)/$(PKG_NAME)

58
package/system/zram-swap/files/zram.init
View File

@ -106,6 +106,54 @@ zram_comp_streams()
fi
}
zram_stats()
{
#print various stats info about zram swap device
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" )"
old_mem_used=`awk '{print $3}' <$zdev/mm_stat`
old_overhead=`awk '{print $3-$2}' <$zdev/mm_stat`
echo ""
echo "Compacting zram device..."
echo 1 > $zdev/compact
awk -v old_mem="$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()
{
local zram_size="$( zram_size )"
@ -113,7 +161,15 @@ start()
if [ $( grep -cs zram /proc/swaps ) -ne 0 ]; then
logger -s -t zram_start -p daemon.notice "[OK] zram swap is already mounted"
return 1
# If not running interactively, than just quit
[ -z "$PS1" ] && return 1
# show memory stats and compact all zram swaps
for zram_dev in $( grep zram /proc/swaps |awk '{print $1}' ); do {
zram_compact "$zram_dev"
zram_stats "$zram_dev"
} done
return
fi
zram_dev="$( zram_getdev )"