Hi Ohad,

On Friday, January 27, 2012 10:44 AM Ohad Ben-Cohen wrote:

With v19, I can't seem to allocate big regions anymore (e.g. 101MiB).
In particular, this seems to fail:

On Thu, Jan 26, 2012 at 11:00 AM, Marek Szyprowski
[off-list ref] wrote:

quoted

+static int cma_activate_area(unsigned long base_pfn, unsigned long count)
+{
+ ? ? ? unsigned long pfn = base_pfn;
+ ? ? ? unsigned i = count >> pageblock_order;
+ ? ? ? struct zone *zone;
+
+ ? ? ? WARN_ON_ONCE(!pfn_valid(pfn));
+ ? ? ? zone = page_zone(pfn_to_page(pfn));
+
+ ? ? ? do {
+ ? ? ? ? ? ? ? unsigned j;
+ ? ? ? ? ? ? ? base_pfn = pfn;
+ ? ? ? ? ? ? ? for (j = pageblock_nr_pages; j; --j, pfn++) {
+ ? ? ? ? ? ? ? ? ? ? ? WARN_ON_ONCE(!pfn_valid(pfn));
+ ? ? ? ? ? ? ? ? ? ? ? if (page_zone(pfn_to_page(pfn)) != zone)
+ ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? return -EINVAL;

The above WARN_ON_ONCE is triggered, and then the conditional is
asserted (page_zone() retuns a "Movable" zone, whereas zone is
"Normal") and the function fails.

This happens to me on OMAP4 with your 3.3-rc1-cma-v19 branch (and a
bunch of remoteproc/rpmsg patches).

Do big allocations work for you ?

I've tested it with 256MiB on Exynos4 platform. Could you check if the
problem also appears on 3.2-cma-v19 branch (I've uploaded it a few hours
ago) and 3.2-cma-v18? Both are available on our public repo:
git://git.infradead.org/users/kmpark/linux-samsung/

The above code has not been changed since v16, so I'm really surprised 
that it causes problems. Maybe the memory configuration or layout has 
been changed in 3.3-rc1 for OMAP4?

Best regards
-- 
Marek Szyprowski
Samsung Poland R&D Center