ZJIT: Create perf map files for profilers #13941
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This lets us ZJIT compiled functions show up in the profiles of, say, perf, or samply. Fix Shopify#634
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Before: After: |
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There are still some unnamed pointers in there. Perhaps I am not getting the full code range? |
You recorded only the JIT entry trampoline. The frame for the main function would be unnamed, and the name of callees in JIT-to-JIT calls would never appear. I think both of them should have symbols. |
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Oh, silly |
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@k0kubun where should I be adding this? I think I am not finding the right place to get the (start, end) pair |
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That looks better but still has some magic numbers |
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You seem to have removed the symbol from the JIT entry trampoline. By both cases I meant the main function and callee ISEQs, not including the JIT entry. So you need to record symbols in two places now. |
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Awesome, thank you. Very cool |
zjit/src/codegen.rs
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| let start_ptr = start_addr.raw_ptr(cb) as usize; | ||
| let end_ptr = cb.get_write_ptr().raw_ptr(cb) as usize; | ||
| let code_size = end_ptr - start_ptr; | ||
| register_with_perf("entry".into(), start_ptr, code_size); |
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I think it's helpful to include the ISEQ name in the symbol for the entry, also keeping "entry" as part of the symbol. We'd be interested in which ISEQs are called from C, which you could see by looking at the callee frame but it's easier to understand if it's annotated in the frame itself. Using the same "entry" symbol for all entries could be problematic depending on how you aggregate perf profiles too.
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Will do before landing
This lets us ZJIT compiled functions show up in the profiles of, say,
perf, or samply.
Fix Shopify#634