Implement ROMMethodInfo caching support and stack walker integration #22918
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harship04
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Waiting for the changes we discussed before review (but at a glance, looks good so far). |
harship04
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@gacholio , could you please review the PR |
runtime/vm/swalk.c
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| MARK_SLOT_AS_OBJECT(walkState, (j9object_t*) &(methodFrame->specialFrameFlags)); | ||
| walkState->method = methodFrame->method; | ||
| if (NULL != walkState->method) { | ||
| initializeBasicROMMethodInfo(walkState, J9_ROM_METHOD_FROM_RAM_METHOD(walkState->method)); |
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I don't think there should be any remaining callers of the basic init code (other than internally in mapcache.cpp) - they should all be replaced with the new ROM method call (other than the one for a bytecoded PC of course).
runtime/stackmap/mapcache.cpp
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| /* Always compute argument bits */ | ||
| j9localmap_ArgBitsForPC0(romClass, romMethod, newInfo.argbits); | ||
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| if (computeStackAndLocals && pc < (UDATA)J9_BYTECODE_SIZE_FROM_ROM_METHOD(romMethod)) { |
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Please bracket the second clause. In fact, why is this necessary? I think we can assume a running PC is withing the bytecode range of its method.
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| } | ||
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| /* Copy metadata */ |
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Should this not be a call to the basic init code?
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Looks good in general. When computing the maps, you are not checking the size, checking for failure, or setting the bits indicating that the maps have been cached. |
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The argbits do not seem to be being computed at all. |
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| J9ROMMethod *romMethod = J9_ROM_METHOD_FROM_RAM_METHOD(method); | ||
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| /* Use the ROMMethod pointer plus bytecode offset as key */ | ||
| void *key = (void *)((uintptr_t)J9_BYTECODE_START_FROM_ROM_METHOD(romMethod) + (uintptr_t)osrFrame->bytecodePCOffset); |
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This is problematic as it reads the ROM method before checking the cache. Perhaps we need to store the actual PC in the OSR frame. We could then derive the offset in the cache miss case.
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Actually, I'm wrong. The macro does simple addition and does not touch the ROM method memory itself.
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Implements a unified ROM method caching mechanism for consolidating ROM method metadata. Updates stack walking to use the cached information instead of repeated metadata lookups.