Re:Two new ways to read a file quickly
by JoshTriplett on Saturday March 07, 2020 @12:40AM
(#22509996)
Long-term, io_uring will almost certainly going to provide more operations than just I/O.
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Batched virtual memory updates (mmap/munmap/madvise) could be a boon for allocators and garbage collectors since the cost of TLB shootdowns could be amortized.
Similarly if all the syscalls done between fork and exec could be squeezed into a single uring chain without any intervening userspace code then the kernel could skip some costly virtual memory operations, bringing us closer to posix_spawn behavior.
Re:Two new ways to read a file quickly
by JoshTriplett on Saturday March 07, 2020 @03:21PM
(#22513778)
> Batched virtual memory updates (mmap/munmap/madvise) could be a boon for allocators and garbage collectors since the cost of TLB shootdowns could be amortized.
And ideally also the cost of mmap_sem (the lock for an address space's memory map), which can be one of the most contended locks in a workload.
> Similarly if all the syscalls done between fork and exec could be squeezed into a single uring chain without any intervening userspace code then the kernel could skip some costly virtual memory operations, bringing us closer to posix_spawn behavior.
I'd love to see a way of doing this with io_uring.