Bug 258536

Summary:	Bump process priority during responsiveness checks to avoid false positives
Product:	WebKit	Reporter:	Chris Dumez <cdumez>
Component:	WebKit2	Assignee:	Chris Dumez <cdumez>
Status:	REOPENED ---
Severity:	Normal	CC:	commit-queue, kkinnunen, webkit-bug-importer
Priority:	P2	Keywords:	InRadar
Version:	WebKit Nightly Build
Hardware:	Unspecified
OS:	Unspecified
Bug Depends on:	258624
Bug Blocks:

Description Chris Dumez 2023-06-26 15:28:24 PDT

We recently adopted RunningBoard on macOS and our child processes priorities are now tied to RunningBoard assertions that we hold on their behalf. This means that WebProcesses backing background tabs now get a much lower process priority than they used to. Given that the responsiveness timeout is fairly short (3 seconds), this can lead to false positives.

To address the issue, we now hold a foreground assertion during the responsiveness check instead of the implicit background one taken by sendWithAsyncReply().

Comment 1 Chris Dumez 2023-06-26 15:29:58 PDT

Pull request: https://github.com/WebKit/WebKit/pull/15307

Comment 2 EWS 2023-06-26 16:18:39 PDT

Committed 265532@main (5b1e40d5fffc): <https://commits.webkit.org/265532@main>

Reviewed commits have been landed. Closing PR #15307 and removing active labels.

Comment 3 Radar WebKit Bug Importer 2023-06-26 16:19:16 PDT

<rdar://problem/111354639>

Comment 4 WebKit Commit Bot 2023-06-28 08:40:30 PDT

Re-opened since this is blocked by bug 258624