RFR: 8351500: G1: NUMA migrations cause crashes in region allocation [v2]

[Thomas Stuefe]

On Thu, 13 Mar 2025 08:50:40 GMT, Stefan Johansson <sjohanss at openjdk.org> wrote:

> I agree with keeping this patch small and then at some point doing a larger refactor in this area. I also agree that we want the out-parameter last, but when reading the parameters now you get sizing parameters split by the node index parameter, i.e:
> 
> ```
> HeapWord* result = _allocator->attempt_allocation(min_word_size, desired_word_size, node_index, actual_word_size);
> ```
> 
> I would prefer the node index first here, like:
> 
> ```
> HeapWord* result = _allocator->attempt_allocation(node_index, min_word_size, desired_word_size, actual_word_size);
> ```
> 
> For this one:
> 
> ```
>   HeapWord* par_allocate_during_gc(G1HeapRegionAttr dest,
>                                    size_t min_word_size,
>                                    size_t desired_word_size,
>                                    uint node_index,
>                                    size_t* actual_word_size);
> ```
> 
> I would prefer to put the node_index after dest but before the sizes.
> 
> What do you think?

This was actually the first attempt (node_index first) I did, but I found that affected more places that had nothing to do with the patch. OTOH if we plan on reworking this anyway, its better to do it the right way the first time instead of reshuffling the parameters later.

Okay, I change this to node_index first.

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PR Comment: https://git.openjdk.org/jdk/pull/23984#issuecomment-2720522811