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If zram-generator package is installed and works, then we can not remove zram module because zram swap is being used. This case needs a clean zram environment, change this test by using hot_add/hot_remove interface. So even zram device is being used, we still can add zram device and remove them in cleanup. The two interface was introduced since kernel commit 6566d1a32bf7("zram: add dynamic device add/remove functionality") in v4.2-rc1. If kernel supports these two interface, we use hot_add/hot_remove to slove this problem, if not, just check whether zram is being used or built in, then skip it on old kernel. Signed-off-by: Yang Xu <xuyang2018.jy@fujitsu.com> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org> |
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config | ||
Makefile | ||
README | ||
zram01.sh | ||
zram02.sh | ||
zram_lib.sh | ||
zram.sh |
zram: Compressed RAM based block devices ---------------------------------------- * Introduction The zram module creates RAM based block devices named /dev/zram<id> (<id> = 0, 1, ...). Pages written to these disks are compressed and stored in memory itself. These disks allow very fast I/O and compression provides good amounts of memory savings. Some of the usecases include /tmp storage, use as swap disks, various caches under /var and maybe many more :) Statistics for individual zram devices are exported through sysfs nodes at /sys/block/zram<id>/ Kconfig required: CONFIG_ZRAM=y CONFIG_CRYPTO_LZ4=y CONFIG_ZPOOL=y CONFIG_ZSMALLOC=y ZRAM Testcases -------------- zram_lib.sh: create library with initialization/cleanup functions zram.sh: For sanity check of CONFIG_ZRAM and to run zram01 and zram02 Two functional tests: zram01 and zram02: zram01.sh: creates general purpose ram disks with ext4 filesystems zram02.sh: creates block device for swap Commands required for testing: - bc - dd - free - awk - mkswap - swapon - swapoff - mkfs/ mkfs.ext4 For more information please refer: kernel-source-tree/Documentation/admin-guide/blockdev/zram.rst