Adding some chromium devs to the thread.

In, http://lxr.free-electrons.com/source/mm/page_alloc.c#L3152

The default mm retry allocation when 'order <=
PAGE_ALLOC_COSTLY_ORDER' of gfp_mask contains __GFP_REPEAT.
PAGE_ALLOC_COSTLY_ORDER is defined to be 3. On systems with page size
= 4K, this means memory compaction and retry is only done when the
size of allocation is <= 32K
In mwifiex, the allocation size is 64K. When we have system with
memory fragmentation and allocation failed, there will be no retry.
This is why we need to add __GFP_REPEAT here to allow the system to
perform memory compaction and retry allocation.

Maybe Amit@marvell can comment on if this is a good fix on this issue.
I'm also aware that marvell is the progress of implementing
scatter/gatter for mwifiex, which can also fix the issue.

Wei-Ning

On Tue, Mar 29, 2016 at 4:37 PM, Kalle Valo [off-list ref] wrote:

Wei-Ning Huang [off-list ref] writes:

quoted

"single skb allocation failure" happens when system is under heavy
memory pressure.  Add __GFP_REPEAT to skb allocation call so kernel
attempts to reclaim pages and retry the allocation.

Signed-off-by: Wei-Ning Huang <redacted>

Is this really a proper way to fix the issue? This is the first time I'm
hearing about the flag and there isn't even a single user in
drivers/net. I would like to get confirmation from others that
__GFP_REPEAT is really ok to use in a wireless driver before I can take
this.

--
Kalle Valo

-- 
Wei-Ning Huang, 黃偉寧 | Software Engineer, Google Inc., Taiwan |
wnhuang@google.com | Cell: +886 910-380678