I forgot to add ... > On Jun 24, 2020, at 10:26 AM, Mark Lam <mark....@apple.com> wrote: > > Based on all the feedback given so far, it looks like we can move forward > with the following plan: > 1. JSC Debug test bots will build their own local jsc with O3 before running > the tests.
1.5 JSC EWS bot will also run with an O3 Debug build. Mark > 2. The rest of the build and test bots will remain unchanged. > > Let's move forward with this and get the Debug JSC test bot functional again. > > Thanks. > > Mark > > >> On Jun 19, 2020, at 2:58 PM, Alexey Proskuryakov <a...@webkit.org >> <mailto:a...@webkit.org>> wrote: >> >> >> >>> 19 июня 2020 г., в 1:11 PM, Mark Lam <mark....@apple.com >>> <mailto:mark....@apple.com>> написал(а): >>> >>> >>> >>>> On Jun 19, 2020, at 10:24 AM, Geoffrey Garen <gga...@apple.com >>>> <mailto:gga...@apple.com>> wrote: >>>> >>>>>> On Jun 19, 2020, at 8:04 AM, Geoffrey Garen <gga...@apple.com >>>>>> <mailto:gga...@apple.com>> wrote: >>>>>> >>>>>> Can you explain more about what "O3 with no-inlining” is? How does >>>>>> --force-opt=O3 avoid inlining? Would this fully resolve Simon concern >>>>>> about stack traces, or would something still be different about stack >>>>>> traces? >>>>> There doesn't exist a way to do this now, but it'd be trivial to add a >>>>> way. I won't claim it fixes all stack traces differences, but I'd think >>>>> compiling using "-fno-inline -fno-optimize-sibling-calls" would get us >>>>> pretty far in crashing stack traces being similar enough. >>>> >>>> Sounds good. >>>> >>>> I think we should try to refine the proposal along these lines, to >>>> minimize the downsides. I won’t speak for Simon, but for me, being able to >>>> ensure a clear backtrace from a bot would be a big improvement. >>>> >>>>>> And again, I think this discussion would get a lot more focused if the >>>>>> change could apply only to JSC code, and not also to WTF code. >>>>> I believe Mark's proposal, initially, is just to make JSC do this. So I >>>>> don't see the point of compiling WTF differently. JSC can kick off its >>>>> own build, and run Debug+O3 tests faster than it can run Debug+O0 tests. >>>>> Given people working on JSC want this, and people working on JSC defend >>>>> these tests, and that these test results are more stable (see below), we >>>>> should make this change for JSC. >>>>> >>>>> I was trying to convince folks defending non-JSC testing, that they too, >>>>> should want this. I'm not going to pull teeth here. If folks want their >>>>> tests to take ~10x longer to run, they're entitled to make that tradeoff. >>>> >>>> Got it. >>> >>> I'm of the same mind as Saam. We want this change for the JSC bots, and >>> from the time measurements I’ve collected, we can afford to do a clean >>> build for the JSC Debug test runs using O3, and still come out way ahead. >> >> This seems like a reasonable plan. You didn't mention what hardware you >> measured with, but it seems certain to be beneficial on any current hardware. >> >> I need to mention that we saw unexplained and very large impact on JSC test >> speed from enabling/disabling TCSM. That may be a good thing to look into >> while optimizing JSC test speed. >> >> - Alexey >> >> >>> As for non-JSC test runs, I have not actually measured what the time >>> savings are. Given there is resistance to going with O3 there, we don’t >>> have to share the build artifacts for running the tests. JSC test runs >>> should be able to just build JSC for each O3 Debug JSC test run and it is >>> still a win over the current status quo i.e. test runs never complete. >>> >>> Regarding Geoff’s earlier question about whether I know for sure that >>> switching to O3 will fix the current Debug JSC bot failures to run tests, >>> the answer is I’m not certain. The failure is a timeout due to the master >>> bot not seeing any output from the tester bot for more than 20 minutes. >>> I’ve not been able to reproduce this yet. But with a Debug build test run >>> taking 4+ hours, it can only be a progression to switch the Debug JSC test >>> bots to O3. >>> >>> Mark >>> >>> >>>> >>>>>> And again, on the run more tests front, it would be helpful to know >>>>>> whether this change was enough to get the stress tests running or not. >>>>> My experience running the tests locally supports this fully. I don't get >>>>> timeouts when running O3+Debug locally. When running Debug+O0 locally, >>>>> I'd get timeouts all the time, and the total test run would take ~4-8 >>>>> hours. We can wait for official confirmation from Mark. >>>> >>>> Alexey, do the JSC stress tests run now on bots? If not, how fast would >>>> they need to run in order to be eligible to run on bots? >>>> >>>> Thanks, >>>> Geoff >>>> >>>>> >>>>> - Saam >>>>> >>>>>> >>>>>> Thanks, >>>>>> Geoff >>>>>> >>>>>>> On Jun 18, 2020, at 9:30 PM, Saam Barati <sbar...@apple.com >>>>>>> <mailto:sbar...@apple.com>> wrote: >>>>>>> >>>>>>> Why are we insisting on doing something on the bots that takes ~10x >>>>>>> longer to run than necessary? I’d rather have that time spent running >>>>>>> more tests. >>>>>>> >>>>>>> Overall, how we’re doing things now feels like a bad allocation of bot >>>>>>> resources. The differences I see between O3 with no-inlining vs O0 is: >>>>>>> - Some race conditions will behave differently. Race conditions are >>>>>>> already non predictable. I don’t think we’re losing anything here. >>>>>>> - O0 vs O3 is a different compiler. We may encounter bugs in O3 we >>>>>>> don’t in O0, and vice versa. In general, we probably care more about O3 >>>>>>> compiler bugs than O0, since we don’t ship O0, but ship a lot of O3. >>>>>>> >>>>>>> (And if we’re going to insist on “I want it to run what I build at my >>>>>>> desk”: I run debug with O3 at my desk, and I can run debug tests in a >>>>>>> reasonable amount of time now.) >>>>>>> >>>>>>> In evaluating what’s the better setup, I think it’s helpful to think >>>>>>> about this from the other side. Let’s imagine we had Debug+O3 as our >>>>>>> current setup. And someone proposed to move it to O0 and make our tests >>>>>>> take ~10x longer. I think that’d be a non-starter. >>>>>>> >>>>>>> - Saam >>>>>>> >>>>>>>> On Jun 17, 2020, at 9:48 PM, Simon Fraser <simon.fra...@apple.com >>>>>>>> <mailto:simon.fra...@apple.com>> wrote: >>>>>>>> >>>>>>>> I also object to losing good stack traces for crashes on Debug bots. >>>>>>>> >>>>>>>> Also, I don't think Debug bots should build something different from >>>>>>>> what I build at my desk. >>>>>>>> >>>>>>>> Simon >>>>>>>> >>>>>>>>> On Jun 17, 2020, at 1:36 PM, Mark Lam <mark....@apple.com >>>>>>>>> <mailto:mark....@apple.com>> wrote: >>>>>>>>> >>>>>>>>> Hi folks, >>>>>>>>> >>>>>>>>> We're planning to switch the JSC EWS bot and build.webkit.org >>>>>>>>> <http://build.webkit.org/> Debug build and test bots to building with >>>>>>>>> the following set first: >>>>>>>>> ./Tools/Scripts/set-webkit-configuration --force-opt=O3 >>>>>>>>> >>>>>>>>> This means the Debug builds will be built with optimization level >>>>>>>>> forced to O3. >>>>>>>>> >>>>>>>>> Why are we doing this? >>>>>>>>> 1. So that the JSC EWS will start catching ASSERT failures. >>>>>>>>> 2. JSC stress test Debug bots have been timing out and not running >>>>>>>>> tests at all. Hopefully, this change will fix this issue. >>>>>>>>> 3. Tests will run to completion faster and we’ll catch regressions >>>>>>>>> sooner. >>>>>>>>> >>>>>>>>> The downside: crash stack traces will be like Release build stack >>>>>>>>> traces. But I don’t think we should let this deter us. It’s not >>>>>>>>> like there’s no stack information. And just as we do with debugging >>>>>>>>> Release build test failures, we can always do a Debug build locally >>>>>>>>> to do our debugging. >>>>>>>>> >>>>>>>>> We would like to apply this change to all Debug build and test bots, >>>>>>>>> not just the JSC ones. Does anyone strongly object to this change? >>>>>>>>> >>>>>>>>> Thanks. >>>>>>>>> >>>>>>>>> Cheers, >>>>>>>>> Mark >>>>>>>>> >>>>>>>>> _______________________________________________ >>>>>>>>> webkit-dev mailing list >>>>>>>>> webkit-dev@lists.webkit.org <mailto:webkit-dev@lists.webkit.org> >>>>>>>>> https://lists.webkit.org/mailman/listinfo/webkit-dev >>>>>>>>> <https://lists.webkit.org/mailman/listinfo/webkit-dev> >>>>>>>> >>>>>>>> _______________________________________________ >>>>>>>> webkit-dev mailing list >>>>>>>> webkit-dev@lists.webkit.org <mailto:webkit-dev@lists.webkit.org> >>>>>>>> https://lists.webkit.org/mailman/listinfo/webkit-dev >>>>>>>> <https://lists.webkit.org/mailman/listinfo/webkit-dev> >>>>>>> _______________________________________________ >>>>>>> webkit-dev mailing list >>>>>>> webkit-dev@lists.webkit.org <mailto:webkit-dev@lists.webkit.org> >>>>>>> https://lists.webkit.org/mailman/listinfo/webkit-dev >>>>>>> <https://lists.webkit.org/mailman/listinfo/webkit-dev> >>>>>> >>>>> >>>> >>>> _______________________________________________ >>>> webkit-dev mailing list >>>> webkit-dev@lists.webkit.org <mailto:webkit-dev@lists.webkit.org> >>>> https://lists.webkit.org/mailman/listinfo/webkit-dev >>>> <https://lists.webkit.org/mailman/listinfo/webkit-dev> >>> >>> _______________________________________________ >>> webkit-dev mailing list >>> webkit-dev@lists.webkit.org <mailto:webkit-dev@lists.webkit.org> >>> https://lists.webkit.org/mailman/listinfo/webkit-dev >>> <https://lists.webkit.org/mailman/listinfo/webkit-dev> >> >> - Alexey > > _______________________________________________ > webkit-dev mailing list > webkit-dev@lists.webkit.org > https://lists.webkit.org/mailman/listinfo/webkit-dev
_______________________________________________ webkit-dev mailing list webkit-dev@lists.webkit.org https://lists.webkit.org/mailman/listinfo/webkit-dev
