Messages in this thread | | | Date | Wed, 4 Sep 2019 05:55:38 -0700 | From | Christoph Hellwig <> | Subject | Re: dma api errors with swiotlb |
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On Wed, Sep 04, 2019 at 02:54:26PM +0200, Thomas Hellström (VMware) wrote: > On 9/4/19 2:17 PM, Christoph Hellwig wrote: > > A call to dma_max_mapping_size() to limit the maximum I/O size solves > > that problem. With the latest kernel that should actually be done > > automatically by the SCSI midlayer for you. > > Hmm, OK. I guess with a sufficient queue depth and many mappings waiting for > DMA completion, the SWIOTLB may fill up anyway... > > I'll see if I can come up with something.
You are supposed to return SCSI_MLQUEUE_HOST_BUSY in that case, which means that the kernel won't send more commands until another one completed.
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