Messages in this thread | | | Date | Tue, 17 May 2022 11:18:34 +0200 | From | Javier González <> | Subject | Re: [PATCH v4 00/13] support non power of 2 zoned devices |
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On 17.05.2022 10:10, Christoph Hellwig wrote: >I'm a little surprised about all this activity. > >I though the conclusion at LSF/MM was that for Linux itself there >is very little benefit in supporting this scheme. It will massively >fragment the supported based of devices and applications, while only >having the benefit of supporting some Samsung legacy devices.
I believed we had agreed that non-power-of-2 zoned devices was something to explore. Let me summarize the 3 main points we covered at different times at LSF/MM:
- This is not for legacy Samsung ZNS devices. At least 4 other vendors have reported building non-power-of-2 ZNS devices to meet customer demands on removing holes in the address space. It seems like there will be more ZNS devices with size=capacity out there than with PO2 sizes. Block device and FS support is very desirable for these.
- We also talked about how the capacity not being a PO2 is the one introducing the fragmentation, as applications that already worked with SMR HDDs will have to change their data placement policy. The size is just a construction, but the real work is adopting the capacity.
- Besides the previous poit, the fragmentation will happen from the moment we have available devices. This is not a kernel-only issue. We have SMR, ZNS, and soon another spec for zone devices. I understood that as long as we do not break any existing support, we would be able to expend the zoned ecosystem in Linux.
>So my impression was that this work, while technically feasible, is >rather useless. So unless I missed something important I have no >interest in supporting this in NVMe.
Does the above help you reconsidering your interest in supporting this in NVMe?
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