Bug 259371

Summary:	Use mapped files in CacheStorageDiskStore
Product:	WebKit	Reporter:	Ben Nham <nham>
Component:	Website Storage	Assignee:	Ben Nham <nham>
Status:	RESOLVED FIXED
Severity:	Normal	CC:	nham, sihui_liu, webkit-bug-importer
Priority:	P2	Keywords:	InRadar
Version:	WebKit Local Build
Hardware:	Unspecified
OS:	Unspecified

Description Ben Nham 2023-07-20 15:13:33 PDT

Currently CacheStorageDiskStore reads entire files into dirty memory. When many DOMCache operations in flight, this can lead to an temporary explosion in NetworkProcess memory usage (in the gigabytes of footprint).

To fix this issue, we should explore using read-only mapped files in CacheStorageDiskStore instead, as we do with the regular network cache. This trades dirty footprint for higher vnode usage. But presumably that's okay as the number of vnodes that would be consumed by DOMCache should be much lower than the number of vnodes used by NetworkCache.

Comment 1 Radar WebKit Bug Importer 2023-07-20 15:13:56 PDT

<rdar://problem/112623177>

Comment 2 Ben Nham 2023-07-20 15:24:28 PDT

Pull request: https://github.com/WebKit/WebKit/pull/15957

Comment 3 EWS 2023-07-20 21:48:32 PDT

Committed 266199@main (470bd54de983): <https://commits.webkit.org/266199@main>

Reviewed commits have been landed. Closing PR #15957 and removing active labels.