Meeting Details

Topic: linaro-open-discussion meeting
Time: March 22 , 2021 10.00 AM London

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https://linaro-org.zoom.us/j/4417312160

Meeting ID: 441 731 2160
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Meeting ID: 441 731 2160
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Attendees

Lorenzo
Vincent
Jammy
James Morse
Souvik Chakravarty
Jonathan
Jean-Philippe
Shameerali
Salil
Barry Song
Yunsheng Lin
Tao Zeng

Agenda

Confirmed topics

CXL follow up discussion
- https://lore.kernel.org/linux-acpi/C APcyv4gmd_cygXK0PpGkXmJLC3_ctEpRvpi5P-QcuXusFX5oNQ@mail.gmail.com/
- https://lore.kernel.org/linux-acpi/20201102183428.00005f4f@Huawei.com/
Feedback on the virtual CPU hotplug implementation with PSCI
AOB

Meeting Notes

CXL on memory (Jonathan presented several new slides after the introduction in last call)
- Handling of memory on Type 2 devices (like GPU), two modes:
  - Host biased (coherency is managed as part of the host SoC)
  - Device biased (device issues coherence messages)
- Vikram's question: how should it be presented by Firmware?
  - Problem 1: normal memory at boot can't be offlined later
    - Likely to need element of BIOS control
  - Problem 2: pinned memory in region
    - Patch sets under review to migrate memory out of ZONE_MOVABLE on pin
- Generic Initiator Reminder
- GI as bridge for CXL etc.
  - https://lore.kernel.org/linux-acpi/C APcyv4gmd_cygXK0PpGkXmJLC3_ctEpRvpi5P-QcuXusFX5oNQ@mail.gmail.com/
Virtual CPU hotplug
- Salil shared some figures about QEMU boot time impact by the number of CPU cores
  - Pre vCPU Init
  - Post vCPU Init (but pre-VGIC Init)
  - Post VGIC Init
  - Pre Linux Kernel Load
  - Post Kernel Load (But Pre SMBIOS setup)
- LP: we need to converge and do some wrap up for proposal
  - Salil to share some details about how to get the figures
Recording: link (password: *92a8xSE)

Action items

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