When memory-pressure events were first used in an e10s environment it was
to implement memory minimization from about:memory. However when low memory
detection was first introduced in Firefox OS an issue arised with this scheme:
every process was using a kernel-based low-latency mechanism to detect low
memory scenarios and send memory-pressure events; but the main process events
were also being forwarded to all child processes causing listeners to be
triggered twice. Because of this -no-forward events were introduced and used.
Currently however low-memory is detected via polling, so there will always be
a significant delay between the beginning of the low-memory scenario and its
detection. Because of this there is no value in having content processes poll
on their own and it's best to have only the main process do it and then
forward the memory-pressure events to all child processes.
MozReview-Commit-ID: AMQOsEgECme
--HG--
extra : rebase_source : 1b408b31dd27940981407f50f2e5f07e354b16d7
"alloc-failure" is completely unused apart from the description text in nsI-
Memory.idl (and has been since before Firefox 17), while "lowering-priority" is
still being checked for in the PuppetWidget, but otherwise unused as well since
the feature using it was decommissioned in bug 1234176.
Since we're touching the PuppetWidget code anyway, we take the opportunity to
add a check for "low-memory-ongoing" instead, since similar as to how things
used to be with "lowering-priority", we want to drop the LayerManager's cached
resources only when receiving a real full memory-pressure event, but not for
subsequent ongoing notifications.
MozReview-Commit-ID: HL03SOU8axe
--HG--
extra : rebase_source : c988769df36d8d77f4770c71d5c5e0d75c3b99af
They are kept around for the sake of the standalone glue, which is used
for e.g. webapprt, which doesn't have direct access to jemalloc, and thus
still needs a wrapper to go through the xpcom function list and get to
jemalloc from there.
Sylvestre Ledru
Gabriele Svelto
Jan Henning
Nicholas Nethercote
Kan-Ru Chen
Mike Hommey
Maria Grazia Alastra
Andreas Gal
Kartikaya Gupta
Gervase Markham
Benjamin Smedberg
Doug Turner
Mitchell Field
bsmedberg%covad.net
gerv%gerv.net
dougt%netscape.com
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waterson%netscape.com
warren%netscape.com