4 ms·

Its going to be hard to retrofit transactions into the POSIX model with anything other than a very coarse granularity. In the SQL model, statements are assigne

Its going to be hard to retrofit transactions into the POSIX model with anything other than a very coarse granularity. In the SQL model, statements are assigned to a transaction based on which connection they came through. How should POSIX filesystem transactions be scoped? Without rewriting software, its hard to use anything finer-grained than an entire process tree.

kragen 7y ago
An entire process tree costs 100 us of CPU time to create and destroy on modern Linux, so that mechanism could deliver tens of thousands of transactions per second on a modern cellphone. That's probably more than the underlying Flash can make durable, but with nested transactions you might be able to take advantage of more than that. Still, it might be adequate. Unfortunately we are saddled with three generations of software that uses threads like they're going out of style (which they are) due to an unfortunate confluence of Win16 refugees with a misguided attempt to run our transaction processing software on a virtual machine designed for a set-top box with no MMU. You can fork and exit on Linux in 100 us, but not if you have sixteen threads and 512 megabytes of virtual address space spread across 128 mappings.