We have detected a build metrics regression from push: https://hg.mozilla.org/integration/mozilla-inbound/pushloghtml?changeset=01380eb6a6d072f212f8c2f7d194428e2746f0a4 As author of one of the patches included in that push, we need your help to address this regression. Regressions: 13% installer size windows2012-32 opt 53,822,911.38 -> 61,042,618.75 9% installer size windows2012-32 pgo 56,290,022.67 -> 61,373,612.92 7% installer size windows2012-64 opt 59,263,384.46 -> 63,366,772.08 5% installer size windows2012-64 pgo 60,893,806.00 -> 63,680,140.08 Improvements: 27% build times windows2012-32-noopt debug taskcluster-c4.4xlarge 2,120.04 -> 1,544.56 27% build times windows2012-64-noopt debug taskcluster-c4.4xlarge 2,157.27 -> 1,579.23 20% build times windows2012-64 pgo taskcluster-c4.4xlarge 4,559.76 -> 3,668.79 17% build times windows2012-64 debug plain taskcluster-c4.4xlarge 1,989.48 -> 1,660.96 15% build times windows2012-32 pgo taskcluster-c4.4xlarge 4,250.08 -> 3,612.18 15% build times windows2012-64 opt plain taskcluster-c4.4xlarge 2,028.71 -> 1,725.02 11% build times windows2012-32 debug taskcluster-c4.4xlarge 2,345.17 -> 2,078.53 9% build times windows2012-64 debug taskcluster-c4.4xlarge 2,330.82 -> 2,114.59 3% build times windows2012-64 opt taskcluster-c4.4xlarge 2,175.09 -> 2,108.32 3% build times windows2012-32 opt taskcluster-c4.4xlarge 2,127.05 -> 2,067.04 You can find links to graphs and comparison views for each of the above tests at: https://treeherder.mozilla.org/perf.html#/alerts?id=14277 On the page above you can see an alert for each affected platform as well as a link to a graph showing the history of scores for this test. There is also a link to a treeherder page showing the jobs in a pushlog format. To learn more about the regressing test(s), please see: https://developer.mozilla.org/en-US/docs/Mozilla/Performance/Automated_Performance_Testing_and_Sheriffing/Build_Metrics
Component: General → General
Product: Testing → Firefox Build System
Version: Version 3 → unspecified
This regression is not surprising, unfortunately. The size increases are the price we pay for the performance improvements. clang-cl's generated code is generally larger and faster than MSVC's. I made some attempts in bug 1465633 to mitigate this but have mostly given up as I couldn't get any material gains without regressing Talos benchmarks. Down the road, ThinLTO and PGO are going to change the optimization landscape anyway, so it may be worth revisiting the size/speed balance once those optimizations are enabled. Anthony, what do you think?
Flags: needinfo?(dmajor) → needinfo?(ajones)
We should look into the size issue once we get PGO support working. I'd like to keep this bug open until we decide when clang-cl rides the trains.
Almost all our perf tests on Windows improved big time. We only have 2 very strange regressions, that don't make sense at all. I consider them invalid. Even if they were real, the sheer amount of wins is staggering. == Change summary for alert #14271 (as of Tue, 10 Jul 2018 17:22:52 GMT) == Regressions: 3% speedometer windows10-64 pgo e10s stylo 69.06 -> 66.67 3% ts_paint_webext windows10-64 pgo e10s stylo 321.96 -> 331.58 Improvements: 45% stylebench windows7-32 opt e10s stylo 29.33 -> 42.41 40% displaylist_mutate windows7-32 opt e10s stylo5,054.33 -> 3,037.00 40% a11yr windows7-32 opt e10s stylo 305.54 -> 184.29 29% tp6_youtube windows7-32 opt e10s stylo 327.48 -> 233.25 26% displaylist_mutate windows10-64 opt e10s stylo3,965.85 -> 2,918.32 26% tp5o responsiveness windows7-32 opt e10s stylo0.64 -> 0.47 23% tp6_amazon windows7-32 opt e10s stylo 296.90 -> 228.04 23% displaylist_mutate windows7-32 pgo e10s stylo3,818.06 -> 2,957.17 21% speedometer windows7-32 opt e10s stylo 58.48 -> 71.00 20% a11yr windows10-64 opt e10s stylo 238.39 -> 190.08 20% a11yr windows10-64-qr opt e10s stylo 237.39 -> 189.89 18% tsvgx windows7-32 opt e10s stylo 228.77 -> 187.08 18% tp6_youtube windows10-64-qr opt e10s stylo290.17 -> 239.12 17% tsvgr_opacity windows7-32 opt e10s stylo 141.77 -> 117.63 16% displaylist_mutate windows10-64 pgo e10s stylo3,383.95 -> 2,834.30 16% stylebench windows10-64 opt e10s stylo 35.70 -> 41.38 16% tps windows7-32 opt e10s stylo 15.38 -> 12.99 15% tp6_google windows7-32 opt e10s stylo 479.04 -> 405.29 15% stylebench windows10-64-qr opt e10s stylo 37.44 -> 42.94 15% tscrollx windows7-32 opt e10s stylo 0.80 -> 0.68 15% tp6_youtube windows10-64 opt e10s stylo 279.42 -> 238.79 14% about_preferences_basic windows7-32 opt e10s stylo167.48 -> 143.67 14% tp6_facebook windows7-32 opt e10s stylo 175.10 -> 150.50 13% tp5o_scroll windows7-32 opt e10s stylo 0.80 -> 0.70 13% tart windows7-32 opt e10s stylo 3.05 -> 2.66 12% dromaeo_css windows7-32 opt e10s stylo 12,207.58 -> 13,732.37 12% stylebench windows7-32 pgo e10s stylo 37.95 -> 42.62 12% tpaint windows7-32 opt e10s stylo 154.64 -> 135.81 11% sessionrestore_no_auto_restore windows7-32 opt e10s stylo316.62 -> 280.83 11% tscrollx windows10-64 opt e10s stylo 0.73 -> 0.65 11% damp windows7-32 opt e10s stylo 100.62 -> 89.52 11% tp6_amazon windows10-64 opt e10s stylo 260.81 -> 232.29 11% tp6_amazon windows10-64-qr opt e10s stylo 262.98 -> 234.46 11% sessionrestore windows7-32 opt e10s stylo 272.33 -> 243.08 11% tabpaint windows10-64-qr opt e10s stylo 55.49 -> 49.66 10% ts_paint windows7-32 opt e10s stylo 371.42 -> 334.00 10% ts_paint_webext windows7-32 opt e10s stylo374.92 -> 337.67 10% tsvgr_opacity windows10-64 opt e10s stylo 116.72 -> 105.37 10% ts_paint_heavy windows7-32 opt e10s stylo 369.42 -> 334.00 9% speedometer windows10-64 opt e10s stylo 60.14 -> 65.76 9% tabpaint windows7-32 opt e10s stylo 56.35 -> 51.11 9% perf_reftest_singletons windows7-32 pgo e10s stylo53.85 -> 49.01 9% cpstartup content-process-startup windows7-32 opt e10s stylo167.92 -> 153.00 9% tscrollx windows10-64 pgo e10s stylo 0.70 -> 0.64 8% a11yr windows7-32 pgo e10s stylo 192.48 -> 176.48 8% speedometer windows10-64-qr opt e10s stylo60.44 -> 65.42 8% displaylist_mutate windows10-64-qr opt e10s stylo4,320.47 -> 3,966.04 8% tsvgr_opacity windows10-64-qr opt e10s stylo112.58 -> 103.62 8% tp6_facebook windows10-64 opt e10s stylo 167.29 -> 154.21 8% tps windows10-64 opt e10s stylo 15.39 -> 14.20 8% tps windows10-64-qr opt e10s stylo 12.43 -> 11.48 8% tp6_google windows10-64 opt e10s stylo 463.15 -> 428.08 7% tresize windows7-32 opt e10s stylo 8.49 -> 7.87 7% dromaeo_css windows7-32 pgo e10s stylo 12,823.17 -> 13,752.37 7% tp6_facebook windows10-64-qr opt e10s stylo169.12 -> 157.21 7% tp6_google windows10-64-qr opt e10s stylo 456.29 -> 424.12 7% tsvgx windows10-64 opt e10s stylo 150.41 -> 140.19 7% tp5o_scroll windows10-64 opt e10s stylo 0.77 -> 0.72 7% damp windows10-64-qr opt e10s stylo 91.55 -> 85.41 7% sessionrestore_many_windows windows7-32 opt e10s stylo2,435.83 -> 2,273.08 7% tsvgx windows10-64-qr opt e10s stylo 417.68 -> 390.00 6% about_preferences_basic windows10-64 opt e10s stylo155.94 -> 146.02 6% about_preferences_basic windows10-64-qr opt e10s stylo156.44 -> 146.72 6% tp6_facebook windows7-32 pgo e10s stylo 159.46 -> 149.67 6% tart windows10-64 opt e10s stylo 2.83 -> 2.67 5% sessionrestore windows10-64 opt e10s stylo247.62 -> 234.92 5% dromaeo_css windows10-64 opt e10s stylo 12,908.23 -> 13,563.62 5% damp windows10-64 opt e10s stylo 96.59 -> 91.80 5% rasterflood_svg windows7-32 opt e10s stylo10,547.70 -> 10,048.67 5% sessionrestore_no_auto_restore windows10-64 opt e10s stylo286.12 -> 272.58 4% tp6_google windows7-32 pgo e10s stylo 421.52 -> 403.58 4% ts_paint_webext windows10-64-qr opt e10s stylo355.25 -> 340.67 4% ts_paint_heavy windows10-64-qr opt e10s stylo350.71 -> 337.92 4% tps windows7-32 pgo e10s stylo 13.16 -> 12.68 3% tart windows10-64-qr opt e10s stylo 1.53 -> 1.49 3% sessionrestore_many_windows windows10-64 opt e10s stylo2,342.33 -> 2,276.25 2% rasterflood_svg windows10-64 opt e10s stylo10,941.81 -> 10,717.82 For up to date results, see: https://treeherder.mozilla.org/perf.html#/alerts?id=14271eeherder.mozilla.org/perf.html#/alerts?id=14271
The regressions are real and were expected. They should go away with work on LTO/PGO for the clang-cl builds. It's impressive, though, how many (large!) improvements over the PGO(!) MSVC builds there are, considering those builds are not even using LTO or PGO yet!
(In reply to Ionuț Goldan [:igoldan], Performance Sheriffing from comment #3) > For up to date results, see: > https://treeherder.mozilla.org/perf.html#/alerts?id=14271eeherder.mozilla. > org/perf.html#/alerts?id=14271 Sorry for broken link above. Correct one is: https://treeherder.mozilla.org/perf.html#/alerts?id=14271
For the record, I'm shocked at how much better Clang currently is than MSVC PGO. I thought MSVC would be much better than this. This is shaping up to be much more promising on the performance front that I anticipated! I was content with the Clang transition just being about unifying around an open source toolchain. But now the performance benefits look to be as significant of a win. This is amazing!
I'm curious what are the MSVC build flags used by the opt configs (without pgo), such as for "displaylist_mutate windows10-64 opt e10s stylo". Is it -O1 without LTCG, which is the default with ./mach build?
(In reply to lgratian from comment #7) > I'm curious what are the MSVC build flags used by the opt configs (without > pgo), such as for "displaylist_mutate windows10-64 opt e10s stylo". Is it > -O1 without LTCG, which is the default with ./mach build? The Windows optimization flags are -O1 -Oi for Gecko proper and -O2 for the JS engine. It's possible that compiling Gecko with -O2 (-Oi?) would have been a more fair comparison, as we had to bump up the optimization for clang to get performance that was remotely comparable, IIRC.
8 months ago
See Also: → bug 1476265
Enabling PGO in bug 1341525 partially mitigated this regression: we won back 2.8MB/4% of installer size. I don't know why Perfherder didn't raise an alert to this.
(In reply to David Major [:dmajor] from comment #9) > Enabling PGO in bug 1341525 partially mitigated this regression: we won back > 2.8MB/4% of installer size. I don't know why Perfherder didn't raise an > alert to this. Yeah, there may be an issue with Perfherder. I had to manually create the improvement: == Change summary for alert #14720 (as of Thu, 02 Aug 2018 09:39:51 GMT) == Improvements: 3% installer size windows2012-64 pgo 70,330,409.83 -> 68,115,181.08 For up to date results, see: https://treeherder.mozilla.org/perf.html#/alerts?id=14720
See Also: → bug 1481728
I think our users prefer to have a much faster Firefox than a smaller Firefox. I think we should accept this trade-off.
Status: NEW → RESOLVED
Last Resolved: 7 months ago
Resolution: --- → WONTFIX
You need to log in before you can comment on or make changes to this bug.