Bug 207349 - [WTF] Introduce linear-search-threshold for HashTable
Summary: [WTF] Introduce linear-search-threshold for HashTable
Status: NEW
Alias: None
Product: WebKit
Classification: Unclassified
Component: Web Template Framework (show other bugs)
Version: WebKit Nightly Build
Hardware: Unspecified Unspecified
: P2 Normal
Assignee: Yusuke Suzuki
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2020-02-06 12:56 PST by Yusuke Suzuki
Modified: 2020-02-07 11:00 PST (History)
5 users (show)

See Also:


Attachments
Patch (17.79 KB, patch)
2020-02-06 18:01 PST, Yusuke Suzuki
no flags Details | Formatted Diff | Diff

Note You need to log in before you can comment on or make changes to this bug.
Description Yusuke Suzuki 2020-02-06 12:56:00 PST
Let's add linear-search-threshold for HashTable to use higher load-factor for smaller hashtable.

1. Like, setting a linear-search-threshold to 8.
2. Up to 7, we extend capacity when we hit capacity - 1, which is higher load-factor than 75%.
Comment 1 Yusuke Suzuki 2020-02-06 13:46:06 PST
(In reply to Yusuke Suzuki from comment #0)
> Let's add linear-search-threshold for HashTable to use higher load-factor
> for smaller hashtable.
> 
> 1. Like, setting a linear-search-threshold to 8.
> 2. Up to 7, we extend capacity when we hit capacity - 1, which is higher
> load-factor than 75%.

And we should revisit minimumTableSize = 8 definition too. I think this is defined in pre-bmalloc era. So it is assuming malloc is enough slow.
Comment 2 Yusuke Suzuki 2020-02-06 18:01:33 PST
Created attachment 390038 [details]
Patch
Comment 3 Yusuke Suzuki 2020-02-07 11:00:48 PST
The test failures are caused by the bug in the tests relying on particular hash-table iteration order, which is not guaranteed. Need to fix.