RFR: 8225035: Thread stack size issue caused by large TLS size

[Jiangli Zhou]

On Mon, Jun 17, 2019 at 11:39 PM David Holmes <david.holmes at oracle.com>
wrote:

> On 18/06/2019 8:41 am, Jiangli Zhou wrote:
> > Hi Andrew and Florian,
> >
> > With the stack size needs to be aligned at page boundary, it seems that
> > the effect of using large page size is the same for the following two
> > approaches:
> >
> >  1. Using a JVM knob which specifies a minimum stack size for stack size
> >     adjustment (suggested by Florian)
> >  2. Using the value obtained from __pthread_get_minstack for stack size
> >     adjustment
> >
> > The difference is that the second approach gets the adjustment value
> > without guessing, which seems to be more user friendly. What are your
> > thoughts on that? If there is anything that I'm missing, please correct.
> >
> > After thinking more, it seems that the simple approach with an on/off
> > switch (suggested by David initially) that adjusts all threads' stack
> > size (for the on-stack TLS blocks) when the switch is enabled probably
> > is better. Any objections?
>
> As long as it is off by default, no objections here.
>

Ok, thanks for confirming.

Best regards,
Jiangli


>
> Thanks,
> David
>
> > Thanks a lot for all the feedback and suggestions!!
> >
> > Best regards,
> >
> > Jiangli
> >
> > On Mon, Jun 17, 2019 at 3:15 AM Andrew Haley <aph at redhat.com
> > <mailto:aph at redhat.com>> wrote:
> >
> >     On 6/17/19 11:08 AM, Florian Weimer wrote:
> >      >> I think I suggested before to have a JVM knob which specifies a
> >     minimum
> >      >> stack size for passing to libpthread.  This would be a rather
> >      >> straightforward way to deal with applications which specify
> >     impossibly
> >      >> small thread stacks without having to recompile them.  If users
> >      >> encounter a problem and they are on 64-bit architectures, they
> >     can just
> >      >> set that knob to 1 MiB because it's unlikely that they have to
> >     conserve
> >      >> address space.
> >      >
> >      > I still stand behind this suggestion.
> >
> >     This is simple and has the considerable virtue of not needing any
> >     particular
> >     handling of large page sizes.
> >
> >     --
> >     Andrew Haley
> >     Java Platform Lead Engineer
> >     Red Hat UK Ltd. <https://www.redhat.com>
> >     https://keybase.io/andrewhaley
> >     EAC8 43EB D3EF DB98 CC77 2FAD A5CD 6035 332F A671
> >
>