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The code change is fine, but I'm having trouble with "all" here: Both functions aren't even static, so while callers in io_apic.c may benefit (perhaps with the exception of ioapic_{read,write}_entry(), depending on whether the compiler views inlining them as warranted), I'm in no way convinced this extends to the callers in VT-d code. Further ISTR clang being quite a bit less aggressive about inlining, so the effects might not be quite as good there even for the call sites in io_apic.c. Can you clarify this for me please? Jan