russell.gallop added a comment. In D69825#1758949 <https://reviews.llvm.org/D69825#1758949>, @aganea wrote:
> Thanks for the feedback Russell! > > Can you possibly try again with `/MT`? (ie. `-DLLVM_USE_CRT_RELEASE=MT`) I tried adding this to my stage 1 builds and it didn't make any significant difference (times in seconds): No patch (573.879, 568.519, 567.709) With Patch (578.253, 558.515, 562.368) In case it makes a difference, this is from a VS2017 command prompt with Visual Studio 15.9.17. > In the `abba_test.ps1` script, `ninja check-all` is only used for preparing > clang.exe with the patch. The A/B loop //does not// use `check-all`. Ah, yes. Sorry, my mistake. > I also found out that on some of our multi-socket servers, Ninja defaulted to > only the # threads from the first socket. If you had a 2x 18-core system, > Ninja would default to 38 threads (18 x 2 + 2) instead of 74 threads (2 x 18 > x 2 + 2). This behavior seems to be random, depending on the system. This > has been fixed by Ninja PR 1674 > <https://github.com/ninja-build/ninja/pull/1674>, I've tested all our systems > with this patch and they now all default to the proper # of threads. I'm not testing on a multi-socket system so don't believe I need that patch. > I'm doing a new round of tests, I'll get back with updated figures. Thanks. I ran the new version of abba_test.ps1 (just building LLVM) with small modifications to comment out the "Validate Ninja" step and change "check-all" to "all" to save time as I'm concentrating on build build speed. This means that I'm applying it to the same git revision as you. For clang_bypass_cc1.patch I used the patch I downloaded before (before spinning off D70568 <https://reviews.llvm.org/D70568>). Running for one hour on a six core machine (winver 1803, 14 ninja jobs, CFG enabled, recently rebooted) I get: Total iterations: 2 | Min | Mean | Median | Max | A | 00:15:13.0773389 | 00:15:13.7219710 | 00:15:13.7219710 | 00:15:14.3666030 | B | 00:15:08.6134425 | 00:15:09.0363284 | 00:15:09.0363284 | 00:15:09.4592142 | Diff | -00:00:04.4638964 | -00:00:04.6856426 | -00:00:04.6856426 | -00:00:04.9073888 | So in this case it saved 0.5% of time. Using the previous maths, with 2378 clang-cl jobs, this implies process creation time of 29ms. This was fairly soon after a reboot. Maybe I'm just lucky and none of the process creation problems are affecting me on this system (at this moment). CHANGES SINCE LAST ACTION https://reviews.llvm.org/D69825/new/ https://reviews.llvm.org/D69825 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
