On Tue, 2016-03-29 at 17:27 +0800, Wei-Ning Huang wrote: > 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. Before SG is implemented, you really need to copy incoming frames into smallest chunks (to get lowest skb->truesize) and leave the 64KB allocated stuff forever in the driver. __GFP_REPEAT wont really solve the issue. It seems the problem comes from the fact that the drivers calls dev_kfree_skb_any() after calling mwifiex_deaggr_sdio_pkt(), instead of recycling this very precious 64KB skb once memory gets fragmented. Another problem is that mwifiex_deaggr_sdio_pkt() uses mwifiex_alloc_dma_align_buf() with GFP_KERNEL | GFP_DMA Really GFP_DMA makes no sense here, since the skb is going to be processed by the stack, which has no such requirement. Please use normal skb allocations there. diff --git a/drivers/net/wireless/marvell/mwifiex/sdio.c b/drivers/net/wireless/marvell/mwifiex/sdio.c index b2c839a..8404db5 100644 --- a/drivers/net/wireless/marvell/mwifiex/sdio.c +++ b/drivers/net/wireless/marvell/mwifiex/sdio.c @@ -1123,8 +1123,8 @@ static void mwifiex_deaggr_sdio_pkt(struct mwifiex_adapter *adapter, __func__, pkt_len, blk_size); break; } - skb_deaggr = mwifiex_alloc_dma_align_buf(pkt_len, - GFP_KERNEL | GFP_DMA); + skb_deaggr = __netdev_alloc_skb_ip_align(NULL, pkt_len, + GFP_KERNEL); if (!skb_deaggr) break; skb_put(skb_deaggr, pkt_len); -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
