On Mon, 2010-09-27 at 14:25 -0500, Nathan Fontenot wrote:

+static inline int base_memory_block_id(int section_nr)
+{
+       return section_nr / sections_per_block;
+}

...

-       mutex_lock(&mem_sysfs_mutex);
-
-       mem->phys_index = __section_nr(section);
+       scn_nr = __section_nr(section);
+       mem->phys_index = base_memory_block_id(scn_nr) * sections_per_block; 

I'm really regretting giving this variable such a horrid name.  I suck.

I think this is correct now:

	mem->phys_index = base_memory_block_id(scn_nr) * sections_per_block;
	mem->phys_index = section_nr / sections_per_block * sections_per_block;
	mem->phys_index = section_nr

Since it gets exported to userspace this way:

+static ssize_t show_mem_start_phys_index(struct sys_device *dev,
                        struct sysdev_attribute *attr, char *buf)
 {
        struct memory_block *mem =
                container_of(dev, struct memory_block, sysdev);
-       return sprintf(buf, "%08lx\n", mem->phys_index / sections_per_block);
+       unsigned long phys_index;
+
+       phys_index = mem->start_phys_index / sections_per_block;
+       return sprintf(buf, "%08lx\n", phys_index);
+}

The only other thing I'd say is that we need to put phys_index out of
its misery and call it what it is now: a section number.  I think it's
OK to call them "start/end_section_nr", at least inside the kernel.  I
intentionally used "phys_index" terminology in sysfs so that we _could_
eventually do this stuff and break the relationship between sections and
the sysfs dirs, but I think keeping the terminology around inside the
kernel is confusing now.

-- Dave