On 29.09.21 18:25, Mike Rapoport wrote:
On Mon, Sep 27, 2021 at 05:05:16PM +0200, David Hildenbrand wrote:We want to specify flags when hotplugging memory. Let's prepare to pass flags to memblock_add_node() by adjusting all existing users. Note that when hotplugging memory the system is already up and running and we don't want to add the memory first and apply flags later: it should happen within one memblock call.Why is it important that the system is up and why it should happen in a single call? I don't mind adding flags parameter to memblock_add_node() but this changelog does not really explain the reasons to do it.
"After memblock_add_node(), we could race with anybody performing a search for MEMBLOCK_NONE, like kexec_file -- and that only happens once the system is already up and running. So we want both steps to happen atomically."
I can add that to the patch description.(I think it still won't be completely atomic because memblock isn't properly implementing locking yet, but that's a different story)
-- Thanks, David / dhildenb
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