RFR: 8316694: Implement relocation of nmethod within CodeCache [v4]

[Vladimir Kozlov]

On Mon, 17 Mar 2025 21:49:04 GMT, Vladimir Kozlov <kvn at openjdk.org> wrote:

>> The comment to `fix_relocation_after_move` is 17 year old.
>> Is it still valid?
>> We make a copy of nmethod. The copy is not in use. We know call sites might have invalid inline caches. Could we go through the calls sites and clear them?
>> 
>> Requesting a vm operation for each nmethod will be very expensive.
>
> That is very old comment which may be not true anymore. We don't do that when we replace C1 compiled code (tier2-3) with C2 compiled code.

Yes, we need to update call sites. Should we replace all resolved calls with calls to `resolve_*_call` blobs?
Actually `clean_if_nmethod_is_unloaded()` do that. May be we indeed need to call `nmethod::cleanup_inline_caches_impl()` but without VM operation.

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PR Review Comment: https://git.openjdk.org/jdk/pull/23573#discussion_r1999746881