From: Teresa Johnson Date: Fri, 17 Aug 2018 13:19:36 +0000 (+0000) Subject: [ThinLTO] Correct documentation on default number of threads X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=61a414c49a74cde09db8428e3a37dc41cf0d024e;p=clang [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 git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@340021 91177308-0d34-0410-b5e6-96231b3b80d8 --- diff --git a/docs/ThinLTO.rst b/docs/ThinLTO.rst index 38873f464c..05a0b67dba 100644 --- a/docs/ThinLTO.rst +++ b/docs/ThinLTO.rst @@ -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