freebsd stable - Oct 2008 - huge cpu and memory usage by ld.so ?

On RELENG_7 (various versions between june and a few days ago) i
noticed that sometimes ld.so starts using huge amounts of memory
and CPU, both in terms of SIZE and RES.

I saw it first on 3 different machines doing a portupgrade -a
while X was active, but perhaps it is Xorg-related because even
stopping portupgrade the phenomenon continues, and the Xorg process
also comes next in terms of CPU usage (not memory though, it stays
down to reasonable levels).

This is the 'top' output during a portupgrade -a

  PID USERNAME    THR PRI NICE   SIZE    RES STATE  C   TIME   WCPU COMMAND
17385 luigi         1 107    0  2027M   220M RUN    1  19:20 51.37% ld-2.3.6.so

and it really goes up with time, at perhaps 50-100Mbytes per minute.

2 of the machines use the nvidia-driver, one is a Dell X1 laptop
with an i915 board.
Exiting from X seems to terminate the stray ld.so.

I am not sure how reproducible the thing is, or whether it is
a known issue (perhaps portupgrade is replacing some Xorg component
while the Xorg process is using it ?)

	cheers
	luigi

On Tue, Oct 21, 2008 at 12:31:29PM +0200, Luigi Rizzo
wrote:
> On RELENG_7 (various versions between june and a few days ago) i
> noticed that sometimes ld.so starts using huge amounts of memory
> and CPU, both in terms of SIZE and RES.
> 
> I saw it first on 3 different machines doing a portupgrade -a
> while X was active, but perhaps it is Xorg-related because even
> stopping portupgrade the phenomenon continues, and the Xorg process
> also comes next in terms of CPU usage (not memory though, it stays
> down to reasonable levels).
> 
> This is the 'top' output during a portupgrade -a
> 
>   PID USERNAME    THR PRI NICE   SIZE    RES STATE  C   TIME   WCPU COMMAND
> 17385 luigi         1 107    0  2027M   220M RUN    1  19:20 51.37%
ld-2.3.6.so
> 
> and it really goes up with time, at perhaps 50-100Mbytes per minute.
> 
> 2 of the machines use the nvidia-driver, one is a Dell X1 laptop
> with an i915 board.
> Exiting from X seems to terminate the stray ld.so.
> 
> I am not sure how reproducible the thing is, or whether it is
> a known issue (perhaps portupgrade is replacing some Xorg component
> while the Xorg process is using it ?)
For the archives- i tracked the problem to be related to the use
of acrobat8 (the viewer) within firefox3 using nspluginwrapper.
What happens is that when you load a pdf document, nsplugin wrapper
runs nppdf.so
> nspluginwrapper -l
/home/luigi/.mozilla/plugins/npwrapper.nppdf.so
  Original plugin:
/usr/local/Adobe/Reader8/ENU/Adobe/Reader8/Browser/intellinux/nppdf.so

which in turn, presumably, calls /compat/linux/lib/ld-2.3.6.so
to load the required libraries. What i see is that the ld-2.3.6.so binary
stays alive throughout the lifetime of the pdf document, and
when i close the tab with the pdf viewer, quite often ld-2.3.6.so does not
disappear but starts eating memory at 1-2MB per second.
I can kill ld-2.3.6.so manually, though i am just a bit unclear on
how exactly i could force the loader to go away when nppdf.so is
unloaded.

cheers
luigi
> 	cheers
> 	luigi