| commit | 529b753bbf17df2d3d18f668e20ce5bc578e63e4 | [log] [tgz] |
|---|---|---|
| author | Mikhail Khokhlov <khokhlov@google.com> | Thu Feb 02 20:52:29 2023 |
| committer | Copybara-Service <copybara-worker@google.com> | Thu Feb 02 20:56:52 2023 |
| tree | fb92ce33e93fb482a6e11088f50b68a4ae4efad9 | |
| parent | 9f6d3c9768bc2b4d87312c6501256d823a1698b9 [diff] |
Reland "Reland "[Tracing] Use Perfetto client library for tracing on Linux"" This is a reland of commit aa7e8dcd5f5665afecaa9463ecbbb8a4ac6d6199 Relanding this again! The following problems have been addressed: 1) TSAN test warnings. A speculative fix for the kind of data race we see on the CI bot has landed. More info at crbug.com/1410450. 2) Benchmark regressions. Most have been fixed (b/265910459), but some remain. Notably, the "number of tasks per frame" metric shows an increase, but since this is a) an artifact of tracing and b) doesn't affect user-visible metrics, I don't think it should block the reland. The continued effort is tracked in b/267622455. 3) Build size increase. So far we were able to reduce the overhead by half (b/266913150 tracks this work). Additional savings can be expected when the migration is complete on all platforms and we are able to remove the old tracing code. Original change's description: > Reland "[Tracing] Use Perfetto client library for tracing on Linux" > > This is a reland of commit d9e2da27d146aedf4cd8fb1dfd75b593fd346e53 > > The build and test failures that were triggered by the original > change have been addressed: > https://chromium-review.googlesource.com/c/v8/v8/+/4152474 > https://chromium-review.googlesource.com/c/chromium/src/+/4154637 > > Original change's description: > > [Tracing] Use Perfetto client library for tracing on Linux > > > > This CL switches the Chrome tracing backend to Perfetto client > > library. It means that Chrome on Linux will use a different set of > > TRACE_EVENT* macros that call Perfetto client API under the hood. > > > > Our end goal is to make Perfetto the default backend on all platforms, > > unblocking multiple improvements in tracing stability and usefulness. > > The Linux change is a first step towards that goal. > > > > Bug: 1006541 > > Change-Id: I85f27a2e4b91f219e9fb4f90a391f4b5df90baa3 > > Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4147340 > > Reviewed-by: Andrew Grieve <agrieve@chromium.org> > > Commit-Queue: Mikhail Khokhlov <khokhlov@google.com> > > Reviewed-by: Eric Seckler <eseckler@chromium.org> > > Cr-Commit-Position: refs/heads/main@{#1090340} > > Bug: 1006541 > Change-Id: I0ba9a161bf92a2268156fce55ab9ba8956c5b1ca > Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4163217 > Reviewed-by: Andrew Grieve <agrieve@chromium.org> > Reviewed-by: Eric Seckler <eseckler@chromium.org> > Commit-Queue: Mikhail Khokhlov <khokhlov@google.com> > Cr-Commit-Position: refs/heads/main@{#1091983} Bug: 1006541 Change-Id: Id6cdcf74beb016853759d6dbbe9f96d03592b4ec Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4218475 Reviewed-by: Andrew Grieve <agrieve@chromium.org> Reviewed-by: Eric Seckler <eseckler@chromium.org> Commit-Queue: Mikhail Khokhlov <khokhlov@google.com> Cr-Commit-Position: refs/heads/main@{#1100623} NOKEYCHECK=True GitOrigin-RevId: a9647f4aa1e4e0941b2ca88c3be49a97694b0eb3
This directory is used to allow different products to customize settings for repos that are DEPS'ed in or shared.
For example: V8 could be built on its own (in a “standalone” configuration), and it could be built as part of Chromium. V8 might define a top-level target, //v8:d8 (a simple executable), that should only be built in the standalone configuration. To figure out whether or not it should be in a standalone configuration, v8 can create a file, build_overrides/v8.gni, that contains a variable, build_standalone_d8 = true. and import it (as import(“//build_overrides/v8.gni”) from its top-level BUILD.gn file.
Chromium, on the other hand, might not need to build d8, and so it would create its own build_overrides/v8.gni file, and in it set build_standalone_d8 = false.
The two files should define the same set of variables, but the values can vary as appropriate to the needs of the two different builds.
The build.gni file provides a way for projects to override defaults for variables used in //build itself (which we want to be shareable between projects).
TODO(crbug.com/588513): Ideally //build_overrides and, in particular, //build_overrides/build.gni should go away completely in favor of some mechanism that can re-use other required files like //.gn, so that we don't have to keep requiring projects to create a bunch of different files to use GN.