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LWN.net Weekly Edition for May 16, 2013
A look at the PyPy 2.0 release
PostgreSQL 9.3 beta: Federated databases and more
LWN.net Weekly Edition for May 9, 2013
(Nearly) full tickless operation in 3.10
How terrible for performance would it be to make all userspace accessible memory no-execute on kernel entrance? (or otherwise achieve the same result, like making it unreachable and then faulting it back in with NX-set).
Yes, you are overly naive...
Posted Jul 22, 2009 17:25 UTC (Wed) by dlang (✭ supporter ✭, #313)
Posted Jul 22, 2009 18:53 UTC (Wed) by PaXTeam (subscriber, #24616)
however there's more cost to this: TLB repopulation which would inevitably occur after returning to userland. that is the real expense as we're talking about up to hundreds of TLB entries on modern CPU cores, each potentially missing in the data cache and incurring hundreds of cycles.
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