Hi Tony,
We use gcc 5.4.0 like you do, and we didn't find any issues whatsoever* (which is, we don't see any segafult happening on O3 regressions) You can verify this by yourself by running upstream regressions There is probably something going wrong in the integration of the patch into your internal fork of gem5. I cannot really help you a lot; judging by your bug report it seems to me that there is an unwanted MOVE (since you have nullptr and the patch is adding move semantics) Regards Giacomo *There is an arm only failure caused by another patch, we are currently looking into that. ________________________________ From: gem5-dev <gem5-dev-boun...@gem5.org> on behalf of Gutierrez, Anthony <anthony.gutier...@amd.com> Sent: 06 December 2018 18:11:12 To: gem5 Developer List Subject: Re: [gem5-dev] Problem with dyn insts/refcnt pointers in O3 LSQ. Yes, sorry, I should have clarified which Giacomo. We are running various GPU benchmarks that link against the ROCm runtime in SE mode. We have internal changes, as this is a merge of upstream master into our internal amd-master branch, but the simulation fails so quickly that we're only executing a handful of memory insts. We don't really have any changes to the CPU model in our internal branch. Do you test with GCC or only clang? -----Original Message----- From: gem5-dev <gem5-dev-boun...@gem5.org> On Behalf Of Giacomo Travaglini Sent: Thursday, December 6, 2018 9:04 AM To: gem5 Developer List <gem5-dev@gem5.org> Subject: Re: [gem5-dev] Problem with dyn insts/refcnt pointers in O3 LSQ. Hi Tony, I guess you are referring to Giacomo Gabrielli (and not me); I will address your comments in any case. Can I ask you 1) Which kind of tests are you talking about? We have run the regressions before posting the change and we didn't find any issue. I will rerun them again just to double check 2) Are you running with upstream master or with your internal branch? Thanks Giacomo ________________________________ From: gem5-dev <gem5-dev-boun...@gem5.org> on behalf of Gutierrez, Anthony <anthony.gutier...@amd.com> Sent: 05 December 2018 22:54:53 To: gem5 Developer List Subject: Re: [gem5-dev] Problem with dyn insts/refcnt pointers in O3 LSQ. I forgot to mention, I am on RHEL 7.3 using gcc 5.4.0 From: Gutierrez, Anthony Sent: Wednesday, December 5, 2018 2:52 PM To: gem5-dev@gem5.org Subject: Problem with dyn insts/refcnt pointers in O3 LSQ. Hi All, I am getting a segfault almost immediately after simulation starts, I think due to this change: https://gem5-review.googlesource.com/c/public/gem5/+/13105/5, as I'm attempting to merge master into our internal master branch. What I see happening is that LSQUnit<Impl>::executeStore() calls LSQUnit<Impl>::checkViolations() and at some point DynInstPtr ld_inst = loadQueue[load_idx]; returns a DynInstPtr whose data is null. I haven't looked at the recent changes to the DynInst and RefCountingPtr closely, but I'm guessing somehow the reference count for the obj is not tracked properly at some point and the object is deleted. Giacomo, do you have any idea what could be causing this? In the meantime, I'll do some debugging to try to understand the issue better. Thanks, Tony _______________________________________________ gem5-dev mailing list gem5-dev@gem5.org http://m5sim.org/mailman/listinfo/gem5-dev IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you. _______________________________________________ gem5-dev mailing list gem5-dev@gem5.org http://m5sim.org/mailman/listinfo/gem5-dev _______________________________________________ gem5-dev mailing list gem5-dev@gem5.org http://m5sim.org/mailman/listinfo/gem5-dev IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you. _______________________________________________ gem5-dev mailing list gem5-dev@gem5.org http://m5sim.org/mailman/listinfo/gem5-dev
