lastweek / nvm-emulator

A kernel-level NVM emulator on bare-metal x86

Non-Volatile Memory Emulator

Copyright (C) 2015-2018 Yizhou Shan <[email protected]>. All rights Reserved.

(Project done in Institute of Computing Technology, Chinese Academy of Science (ICT, CAS) around 2016. It is not maintained anymore. Happy to know one group in HUST has extended this emulator and used it in their research.)

The basic idea is to use Intel PMU to count number of read/writes requests issued from CPU to Memory. Based on this, the emulator manually inject delays to the CPU by running an idle function to emulate the extra read/write latency of NVM. The bandwidth is emulated by limiting the memory controller requests. The whole emulation model is similar to what Quartz is doing.

For anyone who interested in this project:
This emulator is much more complex that it shoud be. We SHOULD leverage the PMU facility already provided by linux kernel. I saw kernel-events improved a lot during These 2 or 3 years. Previously all x86-pmu-events code is in arch/x86/kernel/cpu/, now they have a standalone directory in arch/x86/events/.

Anyway, let us see when toothpaste company Intel will have PM ready for markets.

Publications use this emulator

[1] Caching or Not: Rethinking Virtual File System for Non-Volatile Main Memory, HotStorage'18

nvm-emulator's Issues

give some hits about code

hi, there

I happened to see this repository. I am just curious about how this emulator work.s Could you please give me some hints or docs? PS. I am currently also working on NVM, have already tried some emulator.

Best,

Wei

Re: Error while make

Hello, I am getting some errors while doing make. Can you please tell how to fix that? Thanks.

make -C /lib/modules/5.4.0-52-generic/build/ M=/home/mukti/NVM-Emulator-1.0 modules
make[1]: Entering directory '/usr/src/linux-headers-5.4.0-52-generic'
CC [M] /home/mukti/NVM-Emulator-1.0/uncore_pmu.o
In file included from ./include/linux/kernel.h:15,
from ./include/linux/list.h:9,
from ./include/linux/pci.h:32,
from /home/mukti/NVM-Emulator-1.0/uncore_pmu.h:27,
from /home/mukti/NVM-Emulator-1.0/uncore_pmu.c:36:
/home/mukti/NVM-Emulator-1.0/uncore_pmu.c: In function ‘uncore_print_pci_boxes’:
/home/mukti/NVM-Emulator-1.0/uncore_pmu.c:369:37: error: ‘refcount_t’ {aka ‘struct refcount_struct’} has no member named ‘counter’
369 | box->pdev->dev.kobj.kref.refcount.counter);
| ^
./include/linux/printk.h:303:33: note: in definition of macro ‘pr_printk_hash’
303 | printk(level pr_fmt(format), ##VA_ARGS)
| ^~~~~~~~~~~
/home/mukti/NVM-Emulator-1.0/uncore_pmu.c:360:4: note: in expansion of macro ‘pr_info’
360 | pr_info("......Box%d, in Node%d, %x:%x:%x, %d:%d:%d, Kref = %d",
| ^~~~~~~
make[2]: *** [scripts/Makefile.build:275: /home/mukti/NVM-Emulator-1.0/uncore_pmu.o] Error 1
make[1]: *** [Makefile:1757: /home/mukti/NVM-Emulator-1.0] Error 2
make[1]: Leaving directory '/usr/src/linux-headers-5.4.0-52-generic'
make: *** [Makefile:37: all] Error 2