Closed Bug 1054011 Opened 5 years ago Closed 5 years ago
Why are there sometimes 2 "Preallocated app" processes?
+++ This bug was initially created as a clone of Bug #1047645 +++ From bug 1047645 comment 34: Every 5s: b2g-info 1970-01-09 04:15:39 | megabytes | NAME PID PPID CPU(s) NICE USS PSS RSS SWAP VSIZE OOM_ADJ USER b2g 238 1 910.5 0 9.8 10.7 12.9 40.6 252.2 0 root (Nuwa) 1147 238 3.8 0 0.0 0.1 0.6 7.8 54.1 0 root Video 2376 1147 16.3 18 0.8 0.9 1.8 14.0 85.5 11 u0_a2376 Search Results 3405 1147 6.5 18 4.6 5.1 6.7 7.3 66.2 10 u0_a3405 Camera 3711 1147 11.1 7 4.1 4.9 7.1 12.7 77.4 6 u0_a3711 Homescreen 5461 1147 21.0 1 0.0 0.2 1.1 16.0 77.2 2 u0_a5461 (Preallocated a 11634 1147 1.8 18 0.0 0.1 0.8 11.0 61.2 1 u0_a11634 (Preallocated a 11635 238 3.1 1 2.8 3.5 5.6 8.3 67.1 2 u0_a11635 There are two preallocated processes, one which was forked from the main b2g process, and one which was forked from the Nuwa process. This doesn't seem right.
I'm not sure what this bug depends on, so I'm making it not block 1047645 until we know more about it.
No longer blocks: CAF-v2.0-CC-metabug
I also don't think that this bug depends on the other bugs (copied over from the clone), so I'm removing those too.
Dupe of bug 1051745?
(In reply to Mike Habicher [:mikeh] from comment #3) > Dupe of bug 1051745? Not sure. In bug 1051745, both "Preallocated app" processes have Nuwa as the parent, which may be a different problem.
If Nuwa is there, "Preallocated" processes should not be from plugin-container. Ting, could check it?
Played a while but couldn't reproduce, keep NI and keep trying.
Ran into assersion failure while trying repo, filed bug 1054208.
I can see two preallocated processes, one has parent b2g, one has parent nuwa. But sooner or later the one with parent b2g will become an application. Dave, is this what you saw? ContentParent::CreateBrowserOrApp() will new a ContentParent if there's no spare process, which will fork a preallocated process from b2g process. There are chances to run into this case while Nuwa is forking as there's no spare process.
Flags: needinfo?(tchou) → needinfo?(dhylands)
I just saw this in some output from bug 1047645 and thought it was weird. Why are we using both mechanisms? Shouldn't we just be using one or the other? If its expected under some circumstances, then this should probably just be closed as invalid. I don't know if either one of the preallocated apps went on to become other processes. I guess my concern is that somehow we'll wind up someday with apps which behave differently in some way based on who the parent is.
(In reply to Dave Hylands [:dhylands] from comment #9) > Why are we using both mechanisms? Shouldn't we just be using one or the > other? Actually I don't know :-/ But there's a bug 1033618. I want to make sure it is not the case that none of the two preallocated processes become application. Will try more runs before making this invalid.
(In reply to Dave Hylands [:dhylands] from comment #9) > I just saw this in some output from bug 1047645 and thought it was weird. > Why are we using both mechanisms? Shouldn't we just be using one or the > other? Bug 1054233 tries to fix this. But, for preallocated processes, we do use one or the other. If it is not, there is a bug. That is why Ting is looking on this to make sure that we don't fall into a real bug described here.
There is a bug here, which the app forked from b2g process is not started completely sometimes. I tap application icons fast/randomly to launch multiple apps at the same time. Cards view has two apps "Template" and "IME Tests" which IME one (pid 6542) is not renamed, and the screen stays at app splash screen (backtrace shows epoll_wait() in nsAppShell::ProcessNextNativeEvent()): ting@sweet:~/w/fx/os/flame-v20/gecko$ adb shell b2g-ps APPLICATION SEC USER PID PPID VSIZE RSS WCHAN PC NAME b2g 0 root 2088 1 227348 60136 ffffffff b6e6567c S /system/b2g/b2g (Nuwa) 0 root 2093 2088 65344 6444 ffffffff b6e6567c S /system/b2g/b2g Homescreen 2 u0_a2191 2191 2093 85696 23744 ffffffff b6e6567c S /system/b2g/b2g Template 2 u0_a6496 6496 2093 73316 22584 ffffffff b6e6567c S /system/b2g/b2g (Preallocated a 2 u0_a6540 6540 2093 71176 20188 ffffffff b6e6567c S /system/b2g/b2g (Preallocated a 2 u0_a6542 6542 2088 78684 31228 ffffffff b6e9767c S /system/b2g/plugin-container
Should I file a new bug for comment 12, or use this one?
I filed bug 1056492 for comment 12 as the repro rate is less than 10%, and it is not usual behavior. Close this as invalid since two preallocated processes is expected, check comment 8.
Status: NEW → RESOLVED
Closed: 5 years ago
Resolution: --- → INVALID
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