Messages in this thread | | | From | Mike Frysinger <> | Subject | Re: [RESEND][PATCH] Mark thread stack correctly in proc/<pid>/maps | Date | Fri, 3 Feb 2012 05:29:10 -0500 |
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On Friday 03 February 2012 03:01:35 KOSAKI Motohiro wrote: > > Right now MAP_STACK does not mean anything since it is ignored. The > > intention of this behaviour change is to make MAP_STACK mean that the > > map is going to be used as a stack and hence, set it up like a stack > > ought to be. I could not really think of a valid case for fixed size > > stacks; it looks like a limitation in the pthread implementation in > > glibc rather than a feature. So this patch will actually result in > > uniform behaviour across threads when it comes to stacks. > > > > This does change vm accounting since thread stacks were earlier > > accounted as anon memory. > > The fact is, now process stack and pthread stack clearly behave > different dance. libc don't expect pthread stack grow automatically. > So, your patch will break userland. Just only change display thing.
does it though ? glibc doesn't keep track of the unused address space ... that's what the kernel is for. pthread_attr_setstacksize explicitly operates on the *minimum* stack size, not the *exact* size.
where exactly do you think userland would break ?
http://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_attr_setstacksize.html -mike [unhandled content-type:application/pgp-signature] | |