Bug 248625

Summary:	[webkitpy] Increase the default number of child processes spawned for arm64 Macs
Product:	WebKit	Reporter:	Ryan Haddad <ryanhaddad>
Component:	Tools / Tests	Assignee:	Ryan Haddad <ryanhaddad>
Status:	RESOLVED FIXED
Severity:	Normal	CC:	aakash_jain, ap, emw, jbedard, webkit-bug-importer
Priority:	P2	Keywords:	InRadar
Version:	Other
Hardware:	Unspecified
OS:	Unspecified

Description Ryan Haddad 2022-12-01 12:47:44 PST

We should increate the default number of child processes spawned for arm64 Macs, we currently spawn only 6 for a M1 Mac mini compared with 9 for the latest generation Intel one.

My local testing suggests that doubling the count to 12 appears to be stable and yields about an 18 minute speedup in overall layout test runtime.

Comment 1 Radar WebKit Bug Importer 2022-12-01 12:48:36 PST

<rdar://problem/102873021>

Comment 2 Ryan Haddad 2022-12-01 12:49:29 PST

Maybe there is a better heuristic than simply doubling, but we should consider increasing the count for a short term win before we make further optimizations to overall test runtime.

Comment 3 Ryan Haddad 2022-12-05 16:04:39 PST

Pull request: https://github.com/WebKit/WebKit/pull/7176

Comment 4 EWS 2022-12-12 13:50:58 PST

Committed 257754@main (b0febf1cc635): <https://commits.webkit.org/257754@main>

Reviewed commits have been landed. Closing PR #7176 and removing active labels.