On Thu, 6 Jun 2019, Martin K. Petersen wrote:
>
> Ming,
>
> > Guenter reported scsi boot issue caused by commit c3288dd8c232 ("scsi:
> > core: avoid pre-allocating big SGL for data").
>
> Applied to 5.3/scsi-queue, thank you!
>
Thanks, that seems to fix the esp_scsi regression.
Am I right in thinking that commit c3288dd8c232 ("scsi: core: avoid
pre-allocating big SGL for data") has the effect that any scsi host with
sg_tablesize > 2 must now support chained sg lists?
In commit 4af14d113bcf ("[PATCH] scsi: remove the use_clustering flag"), I
read that "setting the dma_boundary to PAGE_SIZE - 1 and the
max_segment_size to PAGE_SIZE" is sufficient to inhibit clustering. Is
that sufficient to inhibit chained sg lists for LLDs?
Does it follow that #define SCSI_INLINE_SG_CNT 2 is now the upper bound
for sg list entries (clamping sg_tablesize) for those LLDs (regardless
support for chained sg lists)?
Does commit c3288dd8c232 have similar implications for any LLD running on
an architecture with CONFIG_ARCH_NO_SG_CHAIN=y?
I can't find answers to these questions in Documentation/block/biodoc.txt
etc. Any clarification or insight you can offer would be appreciated.
Thanks.
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