Re: Bug#482346: zsh doesn't always wait for its children (-> zombie)

[Vincent Lefevre <vincent@vinc17.org>]

On 2008-05-24 16:40:02 -0700, Phil Pennock wrote:
> Since you're on a rarer architecture that doesn't see so much Linux
> kernel debugging, I'd be inclined to look at what has changed in the
> kernel's architecture-specific signal handling code.  (But see below).

I don't know if the bug is new. I've never killed vlc in such a way
in the past. The current kernel is linux-image-2.6.24-1-powerpc
2.6.24-7.

> Further, it's strange that zombies are contributing to load average; if
> zsh is gone (killed off and no longer even possibly stuck in a tight
> loop)  and there's the zombie and init left, then there shouldn't be
> anything contributing to load avg.

Yes, that's strange.

> If you use tools such as top(1), what processes are they attributing the
> load to?

None, and the CPU is idle:

top - 02:31:55 up 22:19,  6 users,  load average: 4.09, 4.24, 4.25
Tasks: 117 total,   1 running, 115 sleeping,   0 stopped,   1 zombie
Cpu(s):  0.7%us,  0.7%sy,  0.0%ni, 98.4%id,  0.0%wa,  0.3%hi,  0.0%si,  0.0%st
Mem:    255432k total,   233456k used,    21976k free,     3004k buffers
Swap:   524280k total,    22820k used,   501460k free,   105548k cached

(The zombie is vlc.)

>  Is the high load average confirmed by vmstat reports of idle
> CPU, or is the load avg really out of sync with CPU reality?

Here's vmstat output:

ay:~> vmstat
procs -----------memory---------- ---swap-- -----io---- -system-- ----cpu----
 r  b   swpd   free   buff  cache   si   so    bi    bo   in   cs us sy id wa
 0  0  22820  26456   5520  99688    0    0    15    35   30  196  8  1 88  3

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Vincent Lefèvre <vincent@vinc17.org> - Web: <http://www.vinc17.org/>
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