YJIT: Make block invalidation more robust #5145
Merged
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
XrXr
commented
Nov 18, 2021
| @@ -657,43 +677,45 @@ yjit_gen_block(block_t *block, rb_execution_context_t *ec) | |||
|
|
|||
| // Lookup the codegen function for this instruction | |||
| codegen_fn gen_fn = gen_fns[opcode]; | |||
| if (!gen_fn) { | |||
There was a problem hiding this comment.
This change unifies the !gen_fn case and the case where gen_fn returns CANT_COMPILE. They were doing the same thing
|
There are CI failures from the OOM test tripping on trying to generate new entry points while OOM. Looks like we can't have OOM tests until that's fixed because it's too easy to trigger with |
This commit adds an entry_exit field to block_t for use in invalidate_block_version(). By patching the start of the block while invalidating it, invalidate_block_version() can function correctly while there is no executable memory left for new branch stubs. This change additionally fixes correctness for situations where we cannot patch incoming jumps to the invalidated block. In situations such as Shopify/yjit#226, the address to the start of the block is saved and used later, possibly after the block is invalidated. The assume_* family of function now generate block->entry_exit before remembering blocks for invalidation. RubyVM::YJIT.simulate_oom! is introduced for testing out of memory conditions. The test for it is disabled for now because OOM triggers other failure conditions not addressed by this commit. Fixes Shopify/yjit#226
maximecb
approved these changes
Nov 22, 2021
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
This commit adds an entry_exit field to block_t for use in
invalidate_block_version(). By patching the start of the block while
invalidating it, invalidate_block_version() can function correctly
while there is no executable memory left for new branch stubs.
This change additionally fixes correctness for situations where we
cannot patch incoming jumps to the invalidated block. In situations
such as Shopify/yjit#226, the address to the start of the block
is saved and used later, possibly after the block is invalidated.
The assume_* family of function now generate block->entry_exit before
remembering blocks for invalidation.
RubyVM::YJIT.simulate_oom! is introduced for testing out of memory
conditions. The test for it is disabled for now because OOM triggers
other failure conditions not addressed by this commit.
Fixes Shopify/yjit#226