[dpdk-dev] [PATCH v2 0/7] fix DMA mask check
Ferruh Yigit
ferruh.yigit at intel.com
Fri Nov 2 19:38:16 CET 2018
On 11/1/2018 7:53 PM, Alejandro Lucero wrote:
> A patchset sent introducing DMA mask checks has several critical
> issues precluding apps to execute. The patchset was reviewed and
> finally accepted after three versions. Obviously it did not go
> through the proper testing what can be explained, at least from my
> side, due to the big changes to the memory initialization code these
> last months. It turns out the patchset did work with legacy memory
> and I'm afraid that was mainly my testing.
>
> This patchset should solve the main problems reported:
>
> - deadlock duriing initialization
> - segmentation fault with secondary processes
>
> For solving the deadlock, a new API is introduced:
>
> rte_mem_check_dma_mask_safe/unsafe
>
> making the previous rte_mem_check_dma_mask the one those new functions
> end calling. A boolean param is used for calling rte_memseg_walk thread
> safe or thread unsafe. This second option is needed for avoiding the
> deadlock.
>
> For the secondary processes problem, the call to check the dma mask is
> avoided from code being executed before the memory initialization.
> Instead, a new API function, rte_mem_set_dma_mask is introduced, which
> will be used in those cases. The dma mask check is done once the memory
> initialization is completed.
>
> This last change implies the IOVA mode can not be set depending on IOMMU
> hardware limitations, and it is assumed IOVA VA is possible. If the dma
> mask check reports a problem after memory initilization, the error
> message includes now advice for trying with --iova-mode option set to
> pa.
>
> The patchet also includes the dma mask check for legacy memory and the
> no hugepage option.
>
> Finally, all the DMA mask API has been updated for using the same prefix
> than other EAL memory code.
>
> An initial version of this patchset has been tested by Intel DPDK
> Validation team and it seems it solves all the problems reported. This
> final patchset has the same functionality with minor changes. I have
> successfully tested the patchset with my limited testbench.
>
> v2:
> - modify error messages with more descriptive information
> - change safe/unsafe versions for dma check to previous one plus a
> thread_unsafe version.
> - use rte_eal_using_phys_addr instead of getuid
> - fix comments
> - reorder patches
>
> Alejandro Lucero (7):
> mem: fix call to DMA mask check
> mem: use proper prefix
> mem: add function for setting DMA mask
> bus/pci: avoid call to DMA mask check
> mem: modify error message for DMA mask check
> eal/mem: use DMA mask check for legacy memory
> mem: add thread unsafe version for checking DMA mask
Tested-by: Ferruh Yigit <ferruh.yigit at intel.com>
Fixing the deadlock issue, and build/per-patch build is good.
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