Re: [PATCH v8 11/14] x86/mm: Cap flush_tlb_info alignment at 64 bytes

[Sebastian Andrzej Siewior]

On 2026-06-16 19:11:24 [+0800], Chuyi Zhou wrote:
> A stack allocated flush_tlb_info should keep cacheline alignment to
> avoid the regression that motivated the per-CPU storage, but using
> SMP_CACHE_BYTES directly can make the stack frame grow excessively on
> configurations with large cache lines[1].
> 
> Add FLUSH_TLB_INFO_ALIGN and cap the type alignment at 64 bytes. The
> existing per-CPU flush_tlb_info instance remains
> DEFINE_PER_CPU_SHARED_ALIGNED(), so its per-CPU shared-cacheline
> alignment is unchanged.
> 
> The capped type alignment matters once flush_tlb_info is moved back to the
> stack by the next patch.
> 
> link[1]: https://lore.kernel.org/all/tip-780e0106d468a2962b16b52fdf42898f2639e0a0@xxxxxxxxxxxxxx/

I suggest to incorporate a reference such as 

| See commit 780e0106d468a ("x86/mm/tlb: Revert "x86/mm: Align TLB
| invalidation info"") where the usage of SMP_CACHE_BYTES led to 320 bytes
| stack consumption.

This [1] and link and such is just forth and back.

> Signed-off-by: Chuyi Zhou <zhouchuyi@xxxxxxxxxxxxx>

Other than that,
Reviewed-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>

Sebastian