pytorch

7040a070 - [torch] Minor: Avoid ostreamstring in Operator's canonicalSchemaString() (#44442)

[torch] Minor: Avoid ostreamstring in Operator's canonicalSchemaString() (#44442) Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/44442 I noticed lock contention on startup as lookupByLiteral() was calling registerPendingOperators() - some calls were holding the lock for 10+ ms, as operators were being registered. canonicalSchemaString() was using ostreamstring, which isn't typically particularly fast (partly because of c++ spec locale requirements). If we repalce with regular c++ string appends, it's somewhat faster (which isn't hard when comparing with stringstream; albeit a bit more codegen) Over the first minute or so, this cuts out 1.4 seconds under the OperatorRegistry lock (as part of registerPendingOperators) in the first couple minutes of run time (mostly front-loaded) when running sync sgd. As an example, before: registerPendingOperators 12688 usec for 2449 operators After: registerPendingOperators 6853 usec for 2449 operators ghstack-source-id: 111862971 Test Plan: buck test mode/dev-nosan caffe2/test/cpp/... Reviewed By: ailzhang Differential Revision: D23614515 fbshipit-source-id: e712f9dac5bca0b1876e11fb8f0850402f03873a