> From: Wei-Ning Huang [mailto:wnhu...@google.com] > Sent: Tuesday, March 29, 2016 2:57 PM > To: Kalle Valo > Cc: Linux Wireless; LKML; Amitkumar Karwar; Nishant Sarmukadam; Sameer > Nanda; net...@vger.kernel.org; Sonny Rao; Douglas Anderson > Subject: Re: [PATCH] mwifiex: add __GFP_REPEAT to skb allocation call > > 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 >
This fix would be useful. We have a feature called single port aggregation in which sometimes data received from SDIO interface can be >32k (but less than 64k). This feature improves throughput performance. We are preparing patches for scatter/gather feature. but scatter/gather won't be supported by some platforms. Hence this fix would still be needed. Regards, Amitkumar
