Bug 225030 - Bump CeilingOnPageSize to 16KB on MIPS
Summary: Bump CeilingOnPageSize to 16KB on MIPS
Status: RESOLVED FIXED
Alias: None
Product: WebKit
Classification: Unclassified
Component: New Bugs (show other bugs)
Version: WebKit Nightly Build
Hardware: Unspecified Unspecified
: P2 Normal
Assignee: Angelos Oikonomopoulos
URL:
Keywords: InRadar
Depends on:
Blocks:
 
Reported: 2021-04-25 02:13 PDT by Angelos Oikonomopoulos
Modified: 2021-05-17 06:59 PDT (History)
10 users (show)

See Also:

Attachments
Patch (1.51 KB, patch)
2021-04-25 02:15 PDT, Angelos Oikonomopoulos 		no flags Details | Formatted Diff | Diff
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Description Angelos Oikonomopoulos 2021-04-25 02:13:17 PDT 
Bump CeilingOnPageSize to 16KB on MIPS
Comment 1 Angelos Oikonomopoulos 2021-04-25 02:15:01 PDT 
Created attachment 426998 [details]
Patch
Comment 2 Michael Catanzaro 2021-04-25 05:45:09 PDT 
Comment on attachment 426998 [details]
Patch

MIPS64 uses a smaller page size than original MIPS? OK.
Comment 3 Angelos Oikonomopoulos 2021-04-26 01:38:47 PDT 
(In reply to Michael Catanzaro from comment #2)
> Comment on attachment 426998 [details]
> Patch
> 
> MIPS64 uses a smaller page size than original MIPS? OK.

AFAIK the choice of page size is up to the kernel -- for non-embedded mips64 systems, some distributions choose a 16KB. Not sure what counts as "original MIPS", but I expect most embedded MIPS systems prefer 4KB pages (which is the previous value for CeilingOnPageSize for MIPS).
Comment 4 EWS 2021-04-26 02:04:10 PDT 
Committed r276583 (237019@main): <https://commits.webkit.org/237019@main>

All reviewed patches have been landed. Closing bug and clearing flags on attachment 426998 [details].
Comment 5 Radar WebKit Bug Importer 2021-04-26 02:05:16 PDT 
<rdar://problem/77143561>
Comment 6 Alberto Garcia 2021-05-15 14:10:07 PDT 
(In reply to Angelos Oikonomopoulos from comment #3)
> > MIPS64 uses a smaller page size than original MIPS? OK.
>
> AFAIK the choice of page size is up to the kernel -- for non-embedded mips64
> systems, some distributions choose a 16KB. Not sure what counts as "original
> MIPS", but I expect most embedded MIPS systems prefer 4KB pages (which is
> the previous value for CeilingOnPageSize for MIPS).

FWIW in Debian we have a downstream patch to use 16KB pages in MIPS64,
it seems that Loongson CPUs don't support 4KB pages.
Comment 7 Angelos Oikonomopoulos 2021-05-17 06:59:57 PDT 
(In reply to Alberto Garcia from comment #6)
[...]
> FWIW in Debian we have a downstream patch to use 16KB pages in MIPS64,
> it seems that Loongson CPUs don't support 4KB pages.

Good to know, thanks!