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The SIGBUS will be only for poisoned PFN; > > > clean PFNs under the same PUD/PMD for sure don't need any SIGBUS, > > > which is the whole purpose of not unmapping. > > > > You can't get a SIGBUS if the things are still mapped. This is why the > > SIGBUS flow requires poking a non-present hole around the poisoned > > memory. > > > > So keeping things mapped at 1G also means giving up on SIGBUS. > > SIGBUS during page fault is definitely impossible when memory is still > mapped, but the platform still MCE or SEA in case of poison > consumption, right? So I wanted to propose new code to SIGBUS (either > BUS_MCEERR_AR or BUS_OBJERR) as long as the platform notifies the > kernel in the synchronous poison consumption context, e.g. MCE on X86 > and SEA on ARM64. So you want a SIGBUS that is delivered asynchronously instead of via the page fault handler? Something like that is sort of what I ment by "eliminate this path", though I didn't think keeping an async SIGBUS was an option? Jason