| commit | 6261c59832fb309da95dbccb8978761631a6a733 | [log] [tgz] |
|---|---|---|
| author | Brian Hamrick <bhamrick@fuchsia.infra.roller.google.com> | Tue Aug 08 20:46:30 2023 +0000 |
| committer | Copybara-Service <copybara-worker@google.com> | Tue Aug 08 13:47:15 2023 -0700 |
| tree | 602916a3ddfb2951ace7fc8c39d8ed273c8581e9 | |
| parent | 8d41edf7269f0c8d22b3598484bfa22f48890a09 [diff] |
[roll] Roll fuchsia [trace-engine] Use release/acquire for rolling_buffer_current_ When tracing in streaming mode, the buffer number being used is stored in rolling_buffer_current_, but the status of a buffer being filled is stored separately. At a buffer swap, the filled status is cleared and then rolling_buffer_current_ is updated to point to the new buffer, but with relaxed memory ordering another thread could observe the second write without the first. That would cause the second thread to believe the new buffer is already full and trigger an unwanted buffer transfer, which would result in the previous contents being transferred a second time along with likely many dropped records. Using release/acquire ordering ensures that the threads that observe the new value of rolling_buffer_current_ also observe the new value of the filled status, i.e. that the buffer is not immediately full. FIXES: b/294082351 TEST: Starnix boot test with fxrev.dev/891233 included, observe that trace does not include duplicated events (though depending on buffer size it may still have some dropped events). Original-Reviewed-on: https://fuchsia-review.googlesource.com/c/fuchsia/+/895984 Original-Revision: a0f556eced11ec0d939babbaf20f604d906ccd2b GitOrigin-RevId: f8227ff3662c862423869601e14cfe0eaa650ccc Change-Id: I430d2ae0b64e0d9e0112e0a3139a774766358465
This repository contains Fuchsia's Global Integration manifest files.
All changes should be made to the internal version of this repository. Our infrastructure automatically updates this version when the internal one changes.
Currently all changes must be made by a Google employee. Non-Google employees wishing to make a change can ask for assistance via the IRC channel #fuchsia on Freenode.
First install Jiri.
Next run:
$ jiri init $ jiri import minimal https://fuchsia.googlesource.com/integration $ jiri update
Third party projects should have their own subdirectory in ./third_party.