This is a port of SplitFS to Linux kernel v5.4.0 for Ubuntu Focal 20.04.
Contents:
kernel/: source code of Linux kernel v5.4.0, with the relink operation added asdynamic_remapsyscall at entry index335forx86_64splitfs/: source code of SplitFStests/: PJD Posix FS test suitemicro/: a simple toy microbenchmark
Required packages for kernel build and splitfs:
sudo apt update
sudo apt install libelf-dev libncurses5-dev bc libboost-devBuild and install kernel deb packages (when menuconfig pops up, tweak any options as desired, or simply save & exit):
cd kernel
./compile_kernel.sh <num_threads>
sudo dpkg -i linux-*.debCheck installed kernel's GRUB menu entry:
awk -F\' '$1=="menuentry " || $1=="submenu " {print i++ " : " $2}; /\tmenuentry / {print "\t" i-1">"j++ " : " $2};' /boot/grub/grub.cfgChange GRUB config to boot into installed kernel:
sudo vim /etc/default/grub
# Say new kernel at 1>4, change to GRUB_DEFAULT="1>4"
# If emulating pmem device with DRAM, add `memmap=8G!4G nokaslr` to GRUB_CMDLINE_LINUX_DEFAULT
# this reserves 8G starting at 4G offset of DRAM as `/dev/pmem0`
sudo update-grub && sudo update-grub2Reboot and verify that the correct kernel is booted with the desired parameters:
sudo reboot
uname -r # should see 5.4.0-91-splitfs
cat /proc/cmdline # check boot parameters
ls /dev # should see /dev/pmem0Build SplitFS dynamic library:
cd splitfs
make clean && make
cd ..Notice that LEDGER_YCSB environment variable is not set here. SplitFS source code uses macro flags (derived from environment variables) extensively to turn code pieces on/off... I was only able to run the microbenchmark successfully without any LEDGER_* variables on.
Format pmem0 into ext4 and mount in DAX mode:
sudo mkfs.ext4 -b 4096 /dev/pmem0
sudo mkdir /mnt/pmem_emul
sudo mount -o dax /dev/pmem0 /mnt/pmem_emul
sudo chown -R $USER /mnt/pmem_emulBuild microbenchmark:
cd micro
make
cd ..Run with raw ext4-DAX:
sudo sync && sudo bash -c 'echo 3 > /proc/sys/vm/drop_caches'
./micro/rw_expt write seq 4096In splitfs/nvp_lock.h line 55 the number of per-core locks is hardcoded:
#define NVP_NUM_LOCKS 32 // == 2 * num of CPU cores, so processes running over SplitFS must be on CPU core <= 15 if you have a machine with more cores. Core pinning could be done through taskset.
Run with SplitFS:
rm -f /mnt/pmem_emul/append.log /mnt/pmem_emul/DR-* /mnt/pmem_emul/test.txt
export LD_LIBRARY_PATH=$(realpath .)/splitfs
export NVP_TREE_FILE=$(realpath .)/splitfs/bin/nvp_nvp.tree
sudo sync && sudo bash -c 'echo 3 > /proc/sys/vm/drop_caches'
taskset -c 0-7 bash -c 'LD_PRELOAD=$(realpath .)/splitfs/libnvp.so ./micro/rw_expt write seq 4096'Get LevelDB and compile:
git clone https://github.com/google/leveldb.git
cd leveldb
git submodule update --init --recursive
mkdir -p build && cd build
cmake -DCMAKE_BUILD_TYPE=Release ..
cmake --build . -jTheoretically, LevelDB tests should run successfully through:
rm -f /mnt/pmem_emul/append.log /mnt/pmem_emul/DR-*
mkdir -p /mnt/pmem_emul/leveldbdir
export LD_LIBRARY_PATH=$(realpath .)/splitfs
export NVP_TREE_FILE=$(realpath .)/splitfs/bin/nvp_nvp.tree
taskset -c 0-7 bash -c 'LD_PRELOAD=$(realpath .)/splitfs/libnvp.so TEST_TMPDIR=/mnt/pmem_emul/leveldbdir ./leveldb/build/leveldb_tests'However, on my side, SplitFS hangs in tests such as SparseMerge. I was not able to debug it because the source code looks like quite a mess.
![dependabot[bot] avatar](https://avatars.githubusercontent.com/in/29110?v=4 "dependabot[bot]")
React
Typescript
Django
Laravel
Facebook
Microsoft
Google
Alibaba
D3
Tencent