[dpdk-dev] [PATCH 1/2] net/mlx4: support externally allocated static memory

Shahaf Shuler shahafs at mellanox.com
Sun Oct 7 13:00:38 CEST 2018


Monday, September 24, 2018 9:37 PM, Yongseok Koh:
> Subject: [PATCH 1/2] net/mlx4: support externally allocated static memory
> 
> When MLX PMD registers memory for DMA, it accesses the global memseg
> list of DPDK to maximize the range of registration so that LKey search can be
> more efficient. Granularity of MR registration is per page.
> 
> Externally allocated memory shouldn't be used for DMA because it can't be
> searched in the memseg list and free event can't be tracked by DPDK. If it is
> used, the following error will occur:
> 
> 	net_mlx5: port 0 unable to find virtually contiguous chunk for
> 	address (0x5600017587c0). rte_memseg_contig_walk() failed.
> 
> There's a pending patchset [1] which enables externally allocated memory.
> Once it is merged, users can register their own memory out of EAL then that
> will resolve this issue.
> 
> Meanwhile, if the external memory is static (allocated on startup and never
> freed), such memory can also be registered by little tweak in the code.
> 
> [1] http://patches.dpdk.org/project/dpdk/list/?series=1415
> 
> This patch is not a bug fix but needs to be included in stable versions.
> 
> Fixes: 9797bfcce1c9 ("net/mlx4: add new memory region support")
> Cc: stable at dpdk.org
> Cc: "Damjan Marion (damarion)" <damarion at cisco.com>
> Cc: Ed Warnicke <hagbard at gmail.com>
> 
> Signed-off-by: Yongseok Koh <yskoh at mellanox.com>
> ---

Series applied to next-net-mlx, thanks. 


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