Stream: git-wasmtime

Topic: wasmtime / PR #3944 Expose details for mlocking modules e...

Wasmtime GitHub notifications bot (Mar 18 2022 at 17:41):

alexcrichton opened PR #3944 from control-over-memory to main:

This commit exposes some various details and config options for having
finer-grain control over mlock-ing the memory of modules. This amounts
to three different changes being present in this commit:

• A new Module::image_range API is added to expose the range in host
  memory of where the compiled image resides. This enables embedders to
  make mlock-ing decisions independently of Wasmtime. Otherwise though
  there's not too much useful that can be done with this range
  information at this time.

• A new Config::force_memory_init_memfd option has been added. This
  option is used to force the usage of memfd_create on Linux even when
  the original module comes from a file on disk. With mlock-ing the main
  purpose for Wasmtime is likely to be avoiding major page faults that
  go back to disk, so this is another major source of avoiding page
  faults by ensuring that the initialization contents of memory are
  always in RAM.

• The memory_images field of a Module has gone back to being lazily
  created on the first instantiation, effectively reverting #3914. This
  enables embedders to defer the creation of the image to as late as
  possible to allow modules to be created from precompiled images
  without actually loading all the contents of the data segments from
  disk immediately.

These changes are all somewhat low-level controls which aren't intended
to be generally used by embedders. If fine-grained control is desired
though it's hoped that these knobs provide what's necessary to be
achieved.

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Wasmtime GitHub notifications bot (Mar 18 2022 at 18:01):

pchickey submitted PR review.

Wasmtime GitHub notifications bot (Mar 18 2022 at 18:51):

alexcrichton merged PR #3944.

Last updated: Dec 23 2024 at 12:05 UTC