Re: [patch 02/28] pm_qos: clean up racy global "name" variable

[Peter Zijlstra]

On Sat, 2009-10-10 at 14:03 -0600, Jonathan Corbet wrote:
> On Sat, 10 Oct 2009 21:54:22 +0200 (CEST)
> John Kacur <jkacur@xxxxxxxxxx> wrote:
> 
> > Hmnn, why 32? Seems arbitrary. At least you see with "process_1234567890" 
> > which is 19, an attempt to show what the maximum string size would be. If 
> > a system were configured to enlarge the maximum PID from 32767 to 4194303 
> > that would still only be 7 digits, so "process_1234567" - which is 16 
> > digits with the newline would enough.
> > 
> > So, I suggest you change that to
> > #define PID_NAME_LEN sizeof("process_1234567")
> 
> ....which works great until somebody enables 64-bit process IDs...:)

PID/TIDs are limited to 2^29, raising it above that will break things
like futexes. Raising it above 2^32 will break heaps of userspace.

That said, 512M tasks still seems like a lot, but if history is
something to go by we'll eventually run out...

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/