JIT: synthesize PGO if no schema, when dynamic PGO is active #101739
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If we know dynamic PGO is active, and we do not find a PGO schema for a method, synthesize PGO data. The schema may be missing if the method was prejitted but not covered by static PGO, or was considered too simple to need profiling (aka minimal profiling). This synthesis removes the possibility of a mixed PGO/no PGO situation. These are problematic, especially in methods that do a lot of inlining. Now when dynamic PGO is active all methods that get optimized will have some form of PGO data. Contributes to dotnet#93020.
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Tagging subscribers to this area: @JulieLeeMSFT, @jakobbotsch |
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@EgorBo PTAL Fairly large number of diffs in PGO scenarios, mostly changes in inlining decisions. Hopefully these are a bit less arbitrary than before. |
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There should be no TP impact to minopts, not sure what's going on there. |
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Must be doing some wasted work -- let me dig in
Previously I had left open the possibility that we might look at profile data even in Tier0. But we're not doing that, and incorporation was blocked by other implicit behaviors when not optimizing, but is no longer blocked. So make it clearer we don't need to run this phase unless we're optimizing. |
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Will run some stress on this once it gets farther along. |
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/azp run runtime-coreclr jitstress, runtime-coreclr libraries-jitstress |
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Azure Pipelines successfully started running 2 pipeline(s). |
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Libraries-jitstress failures are #101721 |
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One jitstress OSX leg hit a CI issue, going to ignore this. |
…101739) If we know dynamic PGO is active, and we do not find a PGO schema for a method, synthesize PGO data. The schema may be missing if the method was prejitted but not covered by static PGO, or was considered too simple to need profiling (aka minimal profiling). This synthesis removes the possibility of a mixed PGO/no PGO situation. These are problematic, especially in methods that do a lot of inlining. Now when dynamic PGO is active all methods that get optimized will have some form of PGO data. Only run profile incorporation when optimizing. Reset BBOPT/pgo vars if we switch away from optimization or have a min opts failover. Contributes to dotnet#93020.
…101739) If we know dynamic PGO is active, and we do not find a PGO schema for a method, synthesize PGO data. The schema may be missing if the method was prejitted but not covered by static PGO, or was considered too simple to need profiling (aka minimal profiling). This synthesis removes the possibility of a mixed PGO/no PGO situation. These are problematic, especially in methods that do a lot of inlining. Now when dynamic PGO is active all methods that get optimized will have some form of PGO data. Only run profile incorporation when optimizing. Reset BBOPT/pgo vars if we switch away from optimization or have a min opts failover. Contributes to dotnet#93020.
If we know dynamic PGO is active, and we do not find a PGO schema for a method, synthesize PGO data. The schema may be missing if the method was prejitted but not covered by static PGO, or was considered too simple to need profiling (aka minimal profiling).
This synthesis removes the possibility of a mixed PGO/no PGO situation. These are problematic, especially in methods that do a lot of inlining. Now when dynamic PGO is active all methods that get optimized will have some form of PGO data.
Contributes to #93020.