ACK/Cmnt: [SRU][N/J:linux-azure][PATCH 0/3] [Arm64] High reboot time for 96 core Linux VMs

[Wei-Lin Chang]

On Mon, Jun 23, 2025 at 10:22:34AM -0500, John Cabaj wrote:
> BugLink: https://bugs.launchpad.net/bugs/2114218
> 
> SRU Justification
> 
> [ Impact ]
> 
> * Microsoft request to fix long boot times on arm64 VMs with 96 cores.
> 
> [ Fix ]
> 
> * Clean cherry-pick of the following patches from upstream:
> * 5c63db59c5f8: "arm64: mm: Don't remap pgtables per-cont(pte|pmd) block"
> * 1fcb7cea8a5f: "arm64: mm: Batch dsb and isb when populating pgtables"
> * 0e9df1c905d8: "arm64: mm: Don't remap pgtables for allocate vs populat"
> 
> [ Test Plan ]
> 
> * Compile tested
> * Microsoft tested
> 
> [ Where problems could occur ]
> 
> * Changes made to memory-management, which could have impacts across the memory subsystems.
> * Backport involved stripping out portions of 5-level paging, which was missing prerequisite
>   commits. This has been validated, but if logic was not well-separated in the upstream commits,
>   the changes for present paging might have some reliance on the 5-level paging changes.
> 
> [ Other info ]
> 
> * SF#00412644
> 
> Ryan Roberts (3):
>   arm64: mm: Don't remap pgtables per-cont(pte|pmd) block
>   arm64: mm: Batch dsb and isb when populating pgtables
>   arm64: mm: Don't remap pgtables for allocate vs populate
> 
>  arch/arm64/include/asm/pgtable.h |  7 ++-
>  arch/arm64/mm/mmu.c              | 92 ++++++++++++++++++--------------
>  2 files changed, 57 insertions(+), 42 deletions(-)
> 
> -- 
> 2.43.0
> 
> 
> -- 
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Hi,

nit: For the backported commits, you have:

"(backported picked from commit <HASH>)"
             ^^^^^^
             extra word here

Otherwise,

Acked-by: Wei-Lin Chang <weilin.chang at canonical.com>