Re: [PATCH] debugobjects: Allow to configure the amount of pre-allocated objects

[Benjamin Block]

On Sat, Mar 14, 2026 at 03:06:49PM -0700, Andrew Morton wrote:
> On Fri, 13 Mar 2026 15:26:20 +0100 Benjamin Block <bblock@xxxxxxxxxxxxx> wrote:
> 
> > > obj_static_pool[] is __initdata, so the consequences of making it large
> > > are very slight.  So do we really need
> > > CONFIG_DEBUG_OBJECTS_POOL_SIZE_SHIFT?  Requiring a rebuild is a huge
> > > hassle.  How about simply making the static pool much larger and leave
> > > it at that?
> > 
> > I was thinking about that but then couldn't decide what would be "big enough"
> > as constant value for "everyone". My test systems wasn't even that "big", and
> > I'm already at 1280 KiB reservation to make ODEBUG "survive" the boot. Not
> > sure I want to make this say 2 MiB without config option for everyone.
> 
> 2MB of initmem probably just doesn't matter.  Annoying.
> 
> Do you understand *why* s390 is using so many objects?  Presumably the
> current much smaller default is OK for most systems - my googling for
> "Out of memory.  ODEBUG disabled" turned up very little.

Frankly, I don't know where all the objects come from on s390. I'll do some
digging, and try to trace the sources.. let's see what I can manage; but I'll
be on a trip for a couple of days.

> Oh, look what I found. 
> https://www.mail-archive.com/linux-kernel@xxxxxxxxxxxxxxx/msg1807440.html
> What happened to that?

Interesting, indeed. Nr. of CPUs and Memory. Well, I had 32 processors and 64
GiB memory, which all things considered isn't particularly huge these days.

-- 
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