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<!DOCTYPE bugzilla SYSTEM "https://bugzilla.yoctoproject.org/page.cgi?id=bugzilla.dtd">

<bugzilla version="5.0.6"
          urlbase="https://bugzilla.yoctoproject.org/"
          
          maintainer="it-coreprojects-helpdesk@linuxfoundation.org"
>

    <bug>
          <bug_id>15851</bug_id>
          
          <creation_ts>2025-05-06 17:19:01 +0000</creation_ts>
          <short_desc>Investigate and reduce significant build time increase</short_desc>
          <delta_ts>2025-11-06 14:35:41 +0000</delta_ts>
          <reporter_accessible>1</reporter_accessible>
          <cclist_accessible>1</cclist_accessible>
          <classification_id>7</classification_id>
          <classification>Build System, Metadata &amp; Runtime</classification>
          <product>OE-Core</product>
          <component>deployment</component>
          <version>5.3</version>
          <rep_platform>x86</rep_platform>
          <op_sys>Multiple</op_sys>
          <bug_status>RESOLVED</bug_status>
          <resolution>FIXED</resolution>
          
          
          <bug_file_loc></bug_file_loc>
          <status_whiteboard></status_whiteboard>
          <keywords></keywords>
          <priority>Medium+</priority>
          <bug_severity>normal</bug_severity>
          <target_milestone>5.3 M3</target_milestone>
          
          <blocked>15852</blocked>
          <everconfirmed>1</everconfirmed>
          <reporter name="Randy MacLeod">randy.macleod</reporter>
          <assigned_to name="Ross Burton">ross.burton</assigned_to>
          <cc>raj.khem</cc>
    
    <cc>ross.burton</cc>
    
    <cc>sundeep.kokkonda</cc>
    
    <cc>sundeep.kokkonda</cc>
          
          
          <cf_os>---</cf_os>
          <cf_regression_type>---</cf_regression_type>
          
          <cf_docchange>Don&apos;t know</cf_docchange>

      

      

      

          <comment_sort_order>oldest_to_newest</comment_sort_order>  
          <long_desc isprivate="0" >
    <commentid>101889</commentid>
    <comment_count>0</comment_count>
    <who name="Randy MacLeod">randy.macleod</who>
    <bug_when>2025-05-06 17:19:01 +0000</bug_when>
    <thetext>Looking at the build time trend in:

https://valkyrie.yocto.io/pub/non-release/20250506-54/testresults/buildperf-alma8/perf-alma8-vk_master_20250506090028_601b05a298.html

for test1: Build core-image-sato
you can see that we have had two increases recently:

1. Commit 78042 - likley mesa: build time went from ~41 to ~61 minutes
   Log: https://git.yoctoproject.org/poky/log/?id=122e9a49614b2ddedaae1d90c06004a7a4c43998

2. Commit 78237 - likely clang: build time went from ~61 to ~76 minutes
   https://git.yoctoproject.org/poky/log/?id=601b05a298c0847e96b8f5f71e50d057e2833382

While these increases were expected, we&apos;d like to look into how we can
eliminate some of the work done or otherwise optimize the build to lower the build time.</thetext>
  </long_desc><long_desc isprivate="0" >
    <commentid>101890</commentid>
    <comment_count>1</comment_count>
    <who name="Randy MacLeod">randy.macleod</who>
    <bug_when>2025-05-06 17:20:32 +0000</bug_when>
    <thetext>Add Ross, Khem, Sundeep.

Sundeep wasn&apos;t in the meeting discussion so FYI, 
Khem has some ideas about changing the defaults for clang:target.</thetext>
  </long_desc><long_desc isprivate="0" >
    <commentid>101899</commentid>
    <comment_count>2</comment_count>
    <who name="Khem Raj">raj.khem</who>
    <bug_when>2025-05-07 15:28:25 +0000</bug_when>
    <thetext>https://lists.openembedded.org/g/openembedded-core/message/216117
https://lists.openembedded.org/g/openembedded-core/message/216116

should help here.</thetext>
  </long_desc><long_desc isprivate="0" >
    <commentid>101997</commentid>
    <comment_count>3</comment_count>
    <who name="Ross Burton">ross.burton</who>
    <bug_when>2025-05-19 14:16:28 +0000</bug_when>
    <thetext>I&apos;ll note that we appear to be building mesa-native with llvmpipe, and I&apos;m not sure if that&apos;s desired.</thetext>
  </long_desc><long_desc isprivate="0" >
    <commentid>102065</commentid>
    <comment_count>4</comment_count>
    <who name="Ross Burton">ross.burton</who>
    <bug_when>2025-05-23 15:28:24 +0000</bug_when>
    <thetext>We currently have a mostly monolithic clang recipe that builds llvm/clang/clang-tools/lldb/libclc in one shot, which is neat but incredibly time consuming.

We do already build compiler-rt, libcxx, and openmp separately.  I think we should extend this further.

As a concrete data point, disabling lldb in clang removed over 100MB from the sysroot and two minutes of build time on my Altra build machine.  Adding a disabled-by-default PACKAGECONFIG to clang for lldb would be prohibitively costly as if a user wants it they&apos;d need to rebuild all of clang again.

libclc and lldb should be the easiest to pull out into separate recipes, although I do note that clang can be configured to use a system llvm, so we should be able to tease apart llvm and clang too, which will help setups which need llvm but not clang (for example, rust).</thetext>
  </long_desc><long_desc isprivate="0" >
    <commentid>102378</commentid>
    <comment_count>5</comment_count>
    <who name="Randy MacLeod">randy.macleod</who>
    <bug_when>2025-07-02 15:10:41 +0000</bug_when>
    <thetext>No significant improvements:

https://valkyrie.yocto.io/pub/non-release/20250702-59/testresults/buildperf-alma8/perf-alma8-vk_master_20250702090029_243d54fd46.html</thetext>
  </long_desc><long_desc isprivate="0" >
    <commentid>102389</commentid>
    <comment_count>6</comment_count>
    <who name="Randy MacLeod">randy.macleod</who>
    <bug_when>2025-07-03 14:53:39 +0000</bug_when>
    <thetext>Hopefully Ross finds time to work on splitting up llvm/clang to reduce build time.</thetext>
  </long_desc><long_desc isprivate="0" >
    <commentid>103177</commentid>
    <comment_count>7</comment_count>
    <who name="Ross Burton">ross.burton</who>
    <bug_when>2025-11-03 18:08:23 +0000</bug_when>
    <thetext>As per https://valkyrie.yocto.io/pub/non-release/20251014-57/testresults/buildperf-alma8/perf-alma8-vk_master_20251014090029_4a1f38dd8d.html we&apos;ve clawed back the hit of building clang.</thetext>
  </long_desc><long_desc isprivate="0" >
    <commentid>103205</commentid>
    <comment_count>8</comment_count>
    <who name="Ross Burton">ross.burton</who>
    <bug_when>2025-11-06 14:35:41 +0000</bug_when>
    <thetext>My next plan involves seeing if we can use libglvnd-native and host drivers instead of mesa-native. But closing as the urgency is done.</thetext>
  </long_desc>
      
      

    </bug>

</bugzilla>