msync in pmfs and other NVM filesystems

Byan, Steve Steve.Byan at
Fri Feb 7 17:12:10 EST 2014

On Feb 7, 2014, at 4:59 PM, Dave Hansen <dave.hansen at> wrote:

> On 02/07/2014 01:43 PM, Byan, Steve wrote:
>> I admit to having not read the code, but I'm hopeful that someone readily knows how, for a msync call, the kernel identifies the correct execute-in-place filesystem(s) to dispatch to for a range of memory. Suppose the application calls msync with a range that specifies more than one mapped file, and those two files are in different XIP filesystems?
> The code is in mm/msync.c.  It's fairly straightforward.
> Essentially, it walks the virtual addresses handed to the system call,
> finds all the parts that are file-backed, and calls vfs_fsync() on the
> _whole_ file.
> FWIW, it doesn't look that efficient or optimized, but it seems to do
> the trick.

Thanks very much, Dave.

Best regards,

Steve Byan
Steve.Byan at

More information about the Linux-pmfs mailing list