Hi Henry, Once we verify other tests with this setup (Impala 2.6, gcc 4.9.3 on ppc64le) and ensure things work, we can try to push the code back to Apache Impala project. But it would have some complications as we are not in sync with the latest cdh5-trunk branch. Latest cdh5-trunk had issues with kudu on power. So, we are on quite old version of cdh5-trunk branch (last rebase in March 3rd week).
Thanks, Nishidha From: Henry Robinson <[email protected]> To: [email protected] Cc: Jim Apple <[email protected]>, Nishidha Panpaliya/Austin/Contr/IBM@IBMUS, Sudarshan Jagadale/Austin/Contr/IBM@IBMUS, Manish Patil/Austin/Contr/IBM@IBMUS, Valencia Serrao/Austin/Contr/IBM@IBMUS, Anup Halarnkar/Austin/Contr/IBM@IBMUS, David Clissold/Austin/IBM@IBMUS, Silvius Rus <[email protected]> Date: 06/15/2016 12:16 AM Subject: Re: Fw: LLVM codegen functionality On 14 June 2016 at 06:58, Nishidha Panpaliya <[email protected]> wrote: Hi Jim, Thank you for your reply. Links that you sent us helped to understand the impact. But I believe, if it is only performance related and not blocking any Impala's feature, we can still live with that issue if it is just not possible to fix either for LLVM community or for us. Please correct me if I misunderstood. It depends what you mean by "we", and "live" :) Are you planning to contribute your changes back to the Apache Impala project? If so, we can discuss omitting codegen support on that issue, preferably on a JIRA. Henry On another note, I could fix gcc 4.9.3 issue with ALTIVEC and could build Impala with it on power. And llvm-codegen test passed on it. So, if everything else works with this setup, we would rather go with gcc 4.9.3 on power for Impala. Thanks again for helping us always. Regards, Nishidha ----- Forwarded by Nishidha Panpaliya/Austin/Contr/IBM on 06/14/2016 07:17 PM ----- From: Sudarshan Jagadale/Austin/Contr/IBM To: Nishidha Panpaliya/Austin/Contr/IBM@IBMUS Date: 06/14/2016 10:35 AM Subject: Fw: LLVM codegen functionality FYI Thanks and Regards Sudarshan Jagadale Power Open Source Solutions ----- Forwarded by Sudarshan Jagadale/Austin/Contr/IBM on 06/14/2016 10:34 AM ----- From: Jim Apple <[email protected]> To: [email protected] Cc: Silvius Rus <[email protected]>, Manish Patil/Austin/Contr/IBM@IBMUS, Sudarshan Jagadale/Austin/Contr/IBM@IBMUS, Valencia Serrao/Austin/Contr/IBM@IBMUS, Anup Halarnkar/Austin/Contr/IBM@IBMUS Date: 06/13/2016 08:33 PM Subject: Re: LLVM codegen functionality LLVM codegen has a significant (and good) effect on performance. https://blog.cloudera.com/blog/2013/02/inside-cloudera-impala-runtime-code-generation/ http://llvm.org/devmtg/2013-11/slides/Wanderman-Milne-Cloudera.pdf As for GCC/altivec problems, you might want to file a bug suggesting that the toolchain use a newer GCC. On Mon, Jun 13, 2016 at 7:58 AM, Nishidha Panpaliya <[email protected]> wrote: > > > Hi All, > > We wanted to know about the significance of llvm codegen feature in Impala. > For us, it is failing on power. And so far, it seems to be due to > incompatibility of LLVM 3.8 with gcc 5. > And building Impala on ppc64le with gcc 4.9 is giving lot of other errors > related to Altivec library. Even LLVM community have no plans to provide > this as a hotfix before 3.9 release. So, we wanted to know how significant > is this functionality. Can we move ahead with this one issue left? What > features are impacted or how users will be affected due to this feature. > > Thanks, > Nishidha -- Henry Robinson Software Engineer Cloudera 415-994-6679
