811467 - Increase image decode chunk size

Status: RESOLVED FIXED

(Core :: Graphics: ImageLib, defect)

Description

[Jeff Muizelaar [:jrmuizel]]

The current size 4096, using telemetry we can see that we can do about image decoding at around 10000 KB/s. This means we can do about 10240 bytes per ms. Since we have 5ms to do the decoding that means we should be able to 51200 bytes in 5ms. I'd suggest we change to 16384 as that gives a healthy margin.

Comment 1

[Jeff Muizelaar [:jrmuizel]]

Attachment: Increase the default to 16384

Increase this limit to 16384. Note tenfour reverted the changes in 666352 for performance reasons.

Comment 2

[Jeff Muizelaar [:jrmuizel]]

Comment on attachment 681209 [details] [diff] [review]
Increase the default to 16384

(this is joe honest)

Comment 3

[Jeff Muizelaar [:jrmuizel]]

https://hg.mozilla.org/integration/mozilla-inbound/rev/cc210f0643e1

Comment 4

[Ed Morley [:emorley]]

https://hg.mozilla.org/mozilla-central/rev/cc210f0643e1

Comment 5

[Nicholas Nethercote [inactive]]

Does this have any impact on memory consumption?  I have no idea how many of these chunks we have live at once.

Comment 6

[Joe Drew (not getting mail)]

Only temporarily in the decoder. These chunks are written from data buffers we are already holding on to.

Comment 7

[Jeff Muizelaar [:jrmuizel]]

(In reply to Joe Drew (:JOEDREW! \o/) from comment #6)
> Only temporarily in the decoder. These chunks are written from data buffers
> we are already holding on to.

And likely not really even in the decoder, because it doesn't make a copy of the source data.