since when does ARM map the kernel memory in sections?

[Nicolas Pitre]

On Tue, 12 Apr 2011, Jamie Lokier wrote:

> Andrei Warkentin wrote:
> > Hi Peter,
> > 
> > 2011/4/12 Peter Wächtler <pwaechtler at mac.com>:
> > > Hello Linux ARM developers,
> > >
> > > did the ARM Linux 2.6 kernel map the kernel memory in pages in the past?
> > > Or was the memory always mapped in sections?
> > >
> > > I still have to chase a potential memory corruption. The rootfs is located on
> > > a SDcard and gets corrupted even when the filesystem test programs write to
> > > different partitions.
> > > The test scenario includes several dozen or even hundreds of warm and cold
> > > boot sequences, file system write tests with sudden soft resets. It's a large
> > > embedded project with a lot of drivers and the fact that always the rootfs and
> > > often the superblock gets damaged let me think of a memory corruption.
> > >
> > 
> > Sorry, I don't want to be obvious, but you mentioned sudden resets
> > while writing, which is almost always going to wind
> > up as fs corruptions, with the severity depending on the level of
> > caching the system is doing to the writes.
> > How are you mounting your rootfs and what file system are you using?
> > What sort of corruptions to the super block are you seeing?
> 
> If everything is implemented correctly, that depends on the type of
> filesystem, block layer and storage.  Some are explicitly designed to
> be safe against sudden reboots and power failure - which is an
> important feature of systems where removing the power is how they are
> turned off at night.

SD was mentioned as being the storage medium in this thread. I really 
doubt SD cards are designed to be safe against sudden power outages.


Nicolas