Bug 222658 – Limit HashTable entry size to 500 bytes

• Status: RESOLVED
• Resolution: FIXED
• Component: New Bugs

[Alex Christensen]

Limit HashTable entry size to 500 bytes

[Alex Christensen]

Created attachment 422097 [details]
Patch

[Alex Christensen]

Created attachment 422121 [details]
Patch

[Yusuke Suzuki]

Comment on attachment 422121 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=422121&action=review

r=me

> Source/WebCore/ChangeLog:14
> +        Moving large structures inside HashTables is slower than just moving a pointer.
> +        There is a point at which it becomes more efficient to add a separate allocation
> +        rather than have gigantic HashTables that use all that memory for each empty slot
> +        and use all those read and write operations to move when rehashing.  I'm not sure
> +        exactly where that point is, but I'm pretty sure it's less than 500 bytes.  This
> +        introduces a limit and removes the two largest HashTables in WebKit, replacing their
> +        values with std::unique_ptr to save memory and time.

Totally right. Furthermore, HashTable allocates large spaces to keep O(1) access. If entry size is large, we waste much more memory than using a pointer.

[EWS]

Committed r273832: <https://commits.webkit.org/r273832>

All reviewed patches have been landed. Closing bug and clearing flags on attachment 422121 [details].

[Radar WebKit Bug Importer]

<rdar://problem/74999075>

[Ryan Haddad]

Reverted r273832 for reason:

26 inspector tests failing a new assert added with this change

Committed r273859 (234825@main): <https://commits.webkit.org/234825@main>

[Ryan Haddad]

(In reply to Ryan Haddad from comment #6)
> Reverted r273832 for reason:
> 
> 26 inspector tests failing a new assert added with this change
Details in https://bugs.webkit.org/show_bug.cgi?id=222696

SHOULD NEVER BE REACHED
/Volumes/Data/worker/bigsur-debug/build/Source/WebKit/NetworkProcess/NetworkConnectionToWebProcess.h(145) : void WebKit::NetworkConnectionToWebProcess::takeNetworkLoadInformationMetrics(WebKit::ResourceLoadIdentifier, CompletionHandler<void (const WebCore::NetworkLoadMetrics &)> &&)

[Alex Christensen]

Created attachment 422177 [details]
Patch

[Yusuke Suzuki]

Comment on attachment 422177 [details]
Patch

r=me.

[EWS]

Committed r273872: <https://commits.webkit.org/r273872>

All reviewed patches have been landed. Closing bug and clearing flags on attachment 422177 [details].