Re: [PATCH 2/3] mm/tlb: Fix wrong judgement in allocate_global_asid()

[Rik van Riel]

On Sat, 2025-03-29 at 21:05 +0800, Hou Wenlong wrote:
> In allocate_global_asid(), 'global_asid_available' cannot be zero, as
> it
> has already been checked in use_global_asid(). Therefore, the warning
> in
> allocate_global_asid() cannot be triggered; fix the wrong judgment in
> allocate_global_asid().
> 
> Fixes: d504d1247e36 ("x86/mm: Add global ASID allocation helper
> functions")
> Signed-off-by: Hou Wenlong <houwenlong.hwl@xxxxxxxxxxxx>

Good catch.

Reviewed-by: Rik van Riel <riel@xxxxxxxxxxx>


Looking at allocate_global_asid() again, I wonder if
that needs to be turned back into a loop.

What if we have no global asids available, and then
an asid gets freed that is smaller than the value
of last_global_asid?
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