780260 - ShadowLayers repaint their image every transaction

Status: RESOLVED FIXED

(Core :: Graphics: Layers, defect)

Description

[Matt Woodrow (:mattwoodrow)]

Attachment: Add a serial number to images to identify them

This is causing significant slow downs when panning around the homescreen on b2g.

Attached patch adds serial numbers to Images and skips repainting the image if it hasn't changed.

Comment 1

[Chris Jones [:cjones] inactive; ni?/f?/r? if you need me]

Comment on attachment 648817 [details] [diff] [review]
Add a serial number to images to identify them

I would feel more comfortable with this if you used uint64_t.

r=me with that.  Nice patch :).

Comment 2

[Matt Woodrow (:mattwoodrow)]

https://hg.mozilla.org/integration/mozilla-inbound/rev/6609595c84eb

Comment 3

[Chris Jones [:cjones] inactive; ni?/f?/r? if you need me]

This took us from 40fps -> 44fps on the gaia homescreen.

Comment 4

[Andrew McCreight [:mccr8]]

It also appears to be leaking a single mutex in inbound.

Comment 5

[:Benjamin Peterson]

Backed out: https://hg.mozilla.org/integration/mozilla-inbound/rev/fd329615ef3e

Comment 6

[:Ms2ger (he/him; ⌚ UTC+1/+2)]

I'm going to blame this for the "ASSERTION: reacquiring already acquired resource" assertions on linux64debug C/R too.

Comment 7

[Matt Woodrow (:mattwoodrow)]

So, I guess we can't have a global Mutex object here :(

Attempting to allocate one the first time we create an image seems like it would have the exact same race condition problems that we will be using it to avoid.

Though it occurs to me that we'd never use images allocated on different threads with the same ImageLayer, so maybe we can remove the Mutex entirely and not worry about potential races.

Comment 8

[Matt Woodrow (:mattwoodrow)]

Attachment: Add a serial number to images to identify them v2

Now using PR_ATOMIC_INCREMENT instead.

Comment 9

[Matt Woodrow (:mattwoodrow)]

https://tbpl.mozilla.org/?tree=Try&rev=903405a03c6e

Comment 10

[Matt Woodrow (:mattwoodrow)]

https://hg.mozilla.org/integration/mozilla-inbound/rev/d76195e9e2b8

Comment 11

[Matt Woodrow (:mattwoodrow)]

https://hg.mozilla.org/integration/mozilla-inbound/rev/7dab8a726f44

Comment 12

[Ed Morley [:emorley]]

https://hg.mozilla.org/mozilla-central/rev/d76195e9e2b8
https://hg.mozilla.org/mozilla-central/rev/7dab8a726f44