Author: tejohnson Date: Fri Aug 17 06:19:36 2018 New Revision: 340021 URL: http://llvm.org/viewvc/llvm-project?rev=340021&view=rev Log: [ThinLTO] Correct documentation on default number of threads
Summary: The number of threads used for ThinLTO backend parallelism was dropped to the number of cores in r284618 to avoid oversubscribing physical cores due to hyperthreading. This updates the documentation to reflect that change. Fixes PR38610. Reviewers: pcc Subscribers: mehdi_amini, inglorion, eraman, steven_wu, dexonsmith, cfe-commits Differential Revision: https://reviews.llvm.org/D50882 Modified: cfe/trunk/docs/ThinLTO.rst Modified: cfe/trunk/docs/ThinLTO.rst URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/docs/ThinLTO.rst?rev=340021&r1=340020&r2=340021&view=diff ============================================================================== --- cfe/trunk/docs/ThinLTO.rst (original) +++ cfe/trunk/docs/ThinLTO.rst Fri Aug 17 06:19:36 2018 @@ -105,7 +105,9 @@ Controlling Backend Parallelism ------------------------------- .. _parallelism: -By default, the ThinLTO link step will launch up to +By default, the ThinLTO link step will launch as many +threads in parallel as there are cores. If the number of +cores can't be computed for the architecture, then it will launch ``std::thread::hardware_concurrency`` number of threads in parallel. For machines with hyper-threading, this is the total number of virtual cores. For some applications and machine configurations this _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
