Move ArenaHeader to Chunk

RESOLVED WONTFIX

Status

()

Core
JavaScript Engine
RESOLVED WONTFIX
8 years ago
7 years ago

People

(Reporter: gwagner, Assigned: gwagner)

Tracking

Firefox Tracking Flags

(Not tracked)

Details

Attachments

(1 attachment, 1 obsolete attachment)

(Assignee)

Description

8 years ago
Measurements show that this accounts for many cache misses.
(Assignee)

Updated

8 years ago
Assignee: general → anygregor
(Assignee)

Comment 2

8 years ago
SS scores don't change much.
For a benchmark I create a linked list with 1000000 objects.
I measure the time[ms] to 
1) create the list
2) GC on whole list
3) delete root and GC

On trunk I get:
40, 87, 49

with this patch:
37, 77, 45
(Assignee)

Comment 3

8 years ago
Nick do you have a way to measure cache performance with this patch?
How does it affect our V8 score?

If you're in Linux, an easy way to measure cache misses is with the perf tool. In Ubuntu, it's in the linux-tools-common package. Just run:
  perf stat ./js ...
and it will print a summary of cache stuff after the command finishes.
(In reply to comment #3)
> Nick do you have a way to measure cache performance with this patch?

Yes.  For what workload?
(Assignee)

Comment 6

8 years ago
(In reply to comment #5)
> (In reply to comment #3)
> > Nick do you have a way to measure cache performance with this patch?
> 
> Yes.  For what workload?

SS, V8 and maybe an allocation heavy page in the browser?

Bill: I saw better scores for V8 in the browser but I still have to verify that this wasn't just noise. Haven't tried with the shell.
(Assignee)

Comment 7

8 years ago
Created attachment 516165 [details] [diff] [review]
patch
Attachment #516090 - Attachment is obsolete: true
I tried SS and V8 in the shell, the changes all looked like noise.  I didn't try in the browser because those results tend to be much less deterministic and so very difficult to detect any meaningful difference that isn't large.
(Assignee)

Updated

7 years ago
Status: NEW → RESOLVED
Last Resolved: 7 years ago
Resolution: --- → WONTFIX
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