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Date: Fri, 18 Sep 2015 10:18:13 -0600
From: Ross Zwisler <ross.zwisler@linux.intel.com>
To: Lin Yongting <linyongting@huawei.com>
Cc: ross.zwisler@linux.intel.com, dan.j.williams@intel.com, axboe@fb.com,
        akpm@linux-foundation.org, richard@nod.at, willy@linux.intel.com,
        wangxiaozhe@huawei.com, mingo@kernel.org, gregkh@linuxfoundation.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH] pramdisk: new block disk driver to perform persistent
 storage
Message-ID: <20150918161813.GA4274@linux.intel.com>
References: <1442562390-91051-1-git-send-email-linyongting@huawei.com>
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On Fri, Sep 18, 2015 at 03:46:30PM +0800, Lin Yongting wrote:
> In embed devices, user space applications will use reserved memory
> (i.e. persistent memory) to store business data, the data is kept
> in this memory region after system rebooting or panic.
> 
> pramdisk is a block disk driver based on Persistent memory, it provide
> file system interface for application to read/write data in persistent
> memory. Application can use pramdisk to store log file or business data
> in persistent memory in the way of file system operation, avoid operating
> or managing memory directly.
> 
> pramdisk support multiple Persistent menory regions and each one is a
> block device named as /dev/pram<N>.
> 
> Usage:
> modprobe pramdisk.ko pmem=<size1>@<addr2> [ pmem=<size2>@<addr2> ... ]
> 
> For example:
>   modprobe pramdisk.ko pmem=20M@2050M pmem=20M@2150M
>   mkfs.ext3 /dev/pram1
>   mkdir /tmp/test1
>   mount -t ext3 /dev/pram1 /tmp/test1
> 
> Signed-off-by: Lin Yongting <linyongting@huawei.com>
> Signed-off-by: Wang xiaozhe <wangxiaozhe@huawei.com>

I think you already have this functionality with the PMEM driver and the
memmap=nn[KMG]!ss[KMG] command line parameter?  What are you trying to
accomplish with this driver that you can't do with PMEM?