On Mon, 2025-03-31 at 15:08 -0400, Randy MacLeod wrote:

On 2025-03-31 12:13 p.m., Khem Raj via lists.openembedded.org wrote:

On Mon, Mar 31, 2025 at 6:30 AM Richard Purdie via lists.openembedded.org <richard.purdie=linuxfoundation.org@lists.openembedded.org> wrote:
Our main llvm recipe uses dynamic linking already but rust-llvm does not.
Enabling this significanly reduces the size of llvm-rust to about a third
of what it was, which is a bettter configuration for us leading to smaller
TMPDIR and sstate objects

It will slow down the compiler execution and sometimes its could be significant as well we have seen this with clang so it would be good to have some idea around that least we provide a slow compiler compared to other distro infrastructures

We'll get some performance info from the YP AB perf builds.

https://valkyrie.yocto.io/pub/non-release/20250331-105/testresults/buildperf-debian11/perf-debian12-vk_master-next_20250331181527_9ba5b4f4e4.html

https://valkyrie.yocto.io/pub/non-release/20250331-104/testresults/buildperf-alma8/perf-alma8-vk_master-next_20250331181513_9ba5b4f4e4.html

The build time is fractionally faster (1%?) but hard to say within noise.

The diskspace drop is convincing, 2.3GB less TMPDIR size (2.3%).

The rm_work TMPDIR size also drops by 1GB (6%) which is particularly significant and nice to have.

In builds with rust-llvm as well as rust-llvm-native, this will double up for a double win.

Cheers,

Richard