Re: [PATCH 2.6.21] cramfs: add cramfs Linear XIP

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Christoph Hellwig wrote:
On Thu, Jun 07, 2007 at 07:07:54PM +0200, Carsten Otte wrote:
I've had a few beer long discussion with Joern Engel and David Woodhouse on this one. To cut a long discussion short: the current XIP infrastructure is not sufficient to be used on top of mtd. We'd need some extenstions: - on get_xip_page() we'd need to state if we want the reference read-only or read+write
- we need a put_xip_page() to return references
- and finally we need a callback for the referece, so that the mtd driver can ask to get its reference back (in order to unmap from userland when erasing a block)

And we'll need that even when using cramfs.  There's not way we'd
merge a hack where the user has to specify a physical address on
the mount command line.
Nay, the proposed solution is read only. From what I understood of the discussion, it does'nt need that. The entire flash memory can be read at the same time. Things start to get interresting when you want to write, then you need to care about erase blocks and such.

While I fully agree, that a flash filesystem using xip would be very desireable, the proposed cramfs extension is a totaly different beast that has its own value to me: the ability to select per file whether xip or compression is more efficient.

You'd of course want all that for a full flash filesystem aswell.
True.

so long,
Carsten
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

[Index of Archives]     [Kernel Newbies]     [Netfilter]     [Bugtraq]     [Photo]     [Stuff]     [Gimp]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Video 4 Linux]     [Linux for the blind]     [Linux Resources]
  Powered by Linux