From bef592844bd2cb1c3561f16ce62c31eecd5cc5d5 Mon Sep 17 00:00:00 2001 From: Hauke Mehrtens Date: Sun, 6 Jan 2013 16:21:29 +0000 Subject: [PATCH] zram: add package to use compressed ram disk for swap The busybox size is increased by 3.2KByte uncompressed on bcm47xx with this commit. This zram-swap automatically creates a zram device, a swap partition on it and make the kernel swap pages to it. Thank you Bastian Bittorf for idea and the script. SVN-Revision: 35025 --- package/busybox/config/util-linux/Config.in | 4 +- package/kernel/modules/other.mk | 21 ++++ package/zram-swap/Makefile | 46 ++++++++ package/zram-swap/files/etc/init.d/zram | 123 ++++++++++++++++++++ 4 files changed, 192 insertions(+), 2 deletions(-) create mode 100644 package/zram-swap/Makefile create mode 100644 package/zram-swap/files/etc/init.d/zram diff --git a/package/busybox/config/util-linux/Config.in b/package/busybox/config/util-linux/Config.in index 14d4777bea..d60b139a8b 100644 --- a/package/busybox/config/util-linux/Config.in +++ b/package/busybox/config/util-linux/Config.in @@ -474,7 +474,7 @@ config BUSYBOX_CONFIG_FEATURE_MDEV_LOAD_FIRMWARE config BUSYBOX_CONFIG_MKSWAP bool "mkswap" - default n + default y help The mkswap utility is used to configure a file or disk partition as Linux swap space. This allows Linux to use the entire file or @@ -652,7 +652,7 @@ config BUSYBOX_CONFIG_SETARCH config BUSYBOX_CONFIG_SWAPONOFF bool "swaponoff" - default n + default y select BUSYBOX_CONFIG_PLATFORM_LINUX help This option enables both the 'swapon' and the 'swapoff' utilities. diff --git a/package/kernel/modules/other.mk b/package/kernel/modules/other.mk index ddaef8d901..5d3e00a87f 100644 --- a/package/kernel/modules/other.mk +++ b/package/kernel/modules/other.mk @@ -747,3 +747,24 @@ define KernelPackage/ikconfig/description endef $(eval $(call KernelPackage,ikconfig)) + + +define KernelPackage/zram + SUBMENU:=$(OTHER_MENU) + TITLE:=ZRAM + DEPENDS:=@!LINUX_3_3 +kmod-lib-lzo + KCONFIG:= \ + CONFIG_ZSMALLOC \ + CONFIG_ZRAM \ + CONFIG_ZRAM_DEBUG=n + FILES:= \ + $(LINUX_DIR)/drivers/staging/zsmalloc/zsmalloc.ko \ + $(LINUX_DIR)/drivers/staging/zram/zram.ko + AUTOLOAD:=$(call AutoLoad,20,zsmalloc zram) +endef + +define KernelPackage/zram/description + Compressed RAM block device support +endef + +$(eval $(call KernelPackage,zram)) diff --git a/package/zram-swap/Makefile b/package/zram-swap/Makefile new file mode 100644 index 0000000000..59a55c4776 --- /dev/null +++ b/package/zram-swap/Makefile @@ -0,0 +1,46 @@ +# +# Copyright (C) 2013 OpenWrt.org +# +# This is free software, licensed under the GNU General Public License v2. +# See /LICENSE for more information. +# + +include $(TOPDIR)/rules.mk + +PKG_NAME:=zram-swap +PKG_VERSION:=1 +PKG_RELEASE:=1 + +PKG_BUILD_DIR := $(BUILD_DIR)/$(PKG_NAME) + +include $(INCLUDE_DIR)/package.mk + +define Package/zram-swap + SECTION:=utils + CATEGORY:=Base system + DEPENDS:=+kmod-zram +!(BUSYBOX_CONFIG_MKSWAP&&BUSYBOX_CONFIG_SWAPONOFF):swap-utils + TITLE:=ZRAM swap scripts + PKGARCH:=all +endef + +define Package/zram-swap/description + A script to activate swaping on a compressed zram partition. This + could be used to increase the available memory, by using compressed + memory. +endef + +define Build/Prepare +endef + +define Build/Configure +endef + +define Build/Compile +endef + +define Package/zram-swap/install + $(INSTALL_DIR) $(1) + $(CP) ./files/* $(1)/ +endef + +$(eval $(call BuildPackage,zram-swap)) diff --git a/package/zram-swap/files/etc/init.d/zram b/package/zram-swap/files/etc/init.d/zram new file mode 100644 index 0000000000..23de915c8f --- /dev/null +++ b/package/zram-swap/files/etc/init.d/zram @@ -0,0 +1,123 @@ +#!/bin/sh /etc/rc.common + +START=15 + +ram_size() +{ + local line + + while read line; do case "$line" in MemTotal:*) set $line; echo "$2"; break ;; esac; done /dev/null || { + logger -s -t zram_applicable -p daemon.err "[ERROR] 'mkswap' not installed" + return 1 + } + + which swapon >/dev/null || { + logger -s -t zram_applicable -p daemon.err "[ERROR] 'swapon' not installed" + return 1 + } + + which swapoff >/dev/null || { + logger -s -t zram_applicable -p daemon.err "[ERROR] 'swapoff' not installed" + return 1 + } +} + +zram_dev() +{ + local core="$1" + + echo "/dev/zram${core:-0}" +} + +zram_reset() +{ + local dev="$1" + local message="$2" + local proc_entry="/sys/block/$( basename "$dev" )/reset" + + logger -s -t zram_reset -p daemon.debug "$message via $proc_entry" + echo "1" >"$proc_entry" +} + +list_cpu_idx() +{ + local line i=0 + + while read line; do { + case "$line" in + [Pp]rocessor*) + echo $i + i=$(( $i + 1 )) + ;; + esac + } done <"/proc/cpuinfo" +} + +start() +{ + # http://shmilyxbq-compcache.googlecode.com/hg/README + # if >1 cpu_core, reinit kmodule with e.g. num_devices=4 + + local zram_size="$( zram_size )" + local zram_dev core + + for core in $( list_cpu_idx ); do { + zram_dev="$( zram_dev "$core" )" + zram_applicable "$zram_dev" || return 1 + + logger -s -t zram_start -p daemon.debug "activating '$zram_dev' for swapping ($zram_size MegaBytes)" + + zram_reset "$zram_dev" "enforcing defaults" + echo $(( $zram_size * 1024 * 1024 )) >"/sys/block/$( basename $zram_dev )/disksize" + mkswap "$zram_dev" + swapon "$zram_dev" + } done +} + +stop() +{ + local zram_dev proc_entry + + for core in $( list_cpu_idx ); do { + zram_dev="$( zram_dev "$core" )" + proc_entry="/sys/block/$( basename "$zram_dev" )/reset" + + grep -sq ^"$zram_dev " /proc/swaps && { + logger -s -t zram_stop -p daemon.debug "deactivate swap $zram_dev" + swapoff "$zram_dev" + } + + zram_reset "$zram_dev" "claiming memory back" + } done +} + -- 2.25.1