cc: Limit the total number of uploads.

cc: Limit the total number of uploads.

We can't reference-count shared memory regions in the GPU
process, so we dup/map the memory block for each upload.
This doesn't scale for small uploads, both because we can
use too many file descriptors, and use too much address
space when the small upload transfer buffers are contained
in larger shared memory blocks.

This limits the total number of uploads to prevent the
problem, but this should be fixed properly and this limit
removed.

BUG=176002
NOTRY=True
Since it's a CC only change and unit tests have passed.


Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=182400

[epenner, 2013-02-14 02:46:07]

Ptal. I was working on a fix which keeps track of all memory we have referenced
so we don't duplicate them a second time, but it would probably add more risk
than we want at this time.

Dave's query latency CL has the same problem, so we'll need to cut the uploads
in half again if we want to land that.

[klobag.chromium, 2013-02-14 04:07:10]

lgtm

[nduca, 2013-02-14 04:31:35]

lgtm

[commit-bot: I haz the power, 2013-02-14 04:38:44]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/epenner@chromium.org/12260033/4002

[commit-bot: I haz the power, 2013-02-14 06:11:29]

Retried try job too often on win_rel for step(s) browser_tests
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=win_rel&nu...

[commit-bot: I haz the power, 2013-02-14 06:14:29]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/epenner@chromium.org/12260033/4002

[commit-bot: I haz the power, 2013-02-14 06:17:11]

Change committed as 182400