Re: [DynInst_API:] TLS-based trampguard patch

[Bill Williams <bill@xxxxxxxxxxx>]

On 02/11/2015 08:06 AM, Gerard wrote:
> I'm not sure if this patch should have solved my problem with the
> maximum number of threads but with this version I still have the same
> problem. If I don't increase the MAX_THREADS constant my instrumented
> process still hangs after creating around 40 threads.
>
> Tested on 64bits Gentoo Linux with kernel version 3.18.3-gentoo.
Huh. Didn't expect that the vestigial bits of thread index code would 
cause a hang; you're sure this is a hang and not a crash mutatee-side?
Anyhow, I've got a more comprehensive patch in the works that eliminates 
MAX_THREADS and the thread index code entirely, and I'll be sending that 
one out later.
> Gerard
>
> 2015-02-06 21:54 GMT+01:00 Bill Williams <bill@xxxxxxxxxxx
> <mailto:bill@xxxxxxxxxxx>>:
>
>     As per discussion earlier this week, here's an initial
>     implementation of TLS-based trampguards. It is not yet pushed to
>     master; I've tested it locally but it has not been through serious
>     cross-platform validation yet. Treat as experimental.
>
>     This should (mostly) obviate our hard-coded thread limits, and
>     should produce modestly better performance in multithreaded code.
>     These changes will not work with an old dyninst runtime library at
>     present; that's backwards compatibility that I can wedge back in if
>     anyone particularly cares. As always, feedback (both good and bad)
>     is encouraged.
>
>     --bw
>
>     Bill Williams
>     Paradyn Project
>     bill@xxxxxxxxxxx <mailto:bill@xxxxxxxxxxx>
>
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--
--bw

Bill Williams
Paradyn Project
bill@xxxxxxxxxxx