Re: [dpdk-dev] [PATCH v2 0/7] fix DMA mask check

[Thomas Monjalon <thomas@monjalon.net>]

02/11/2018 19:38, Ferruh Yigit:
> 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@intel.com>
> 
> Fixing the deadlock issue, and build/per-patch build is good.

Applied, thanks