Messages in this thread | | | Date | Wed, 18 Mar 2009 07:52:23 -0700 (PDT) | From | Linus Torvalds <> | Subject | Re: RT signal queue overflow (Was: Q: SEGSEGV && uc_mcontext->ip (Was: Signal delivery order)) |
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On Wed, 18 Mar 2009, Gábor Melis wrote: > > It was just a month or so ago when I finally made to change to use a > non-real-time signal for signalling stop-for-gc.
Ahh, and that is when you noticed the issue with SIGSEGV?
One thing you might try is to still use a non-real-time signal, but simply depend on the fact that signals are basically peeled off the signal bitmask in a signal number order (with the exception that fatal signals are handled specially).
IOW, on x86, just about the _only_ normal user-generated signal that can happen before SIGSEGV is SIGUSR1, because SIGSEGV is 11, and SIGUSR1 is 10.
If you were to use SIGUSR2 (signal #12) you'd probably never see this.
Of course, there are other signals with numbers < 11, but they are generally meant for other synchronous traps (ie signals like SIGTRAP/AIGABRT/SIGFPE/SIGBUS), or for killing the process (signals SIGHUP/SIGINT/SIGQUIT).
So maybe you'd be happy with just picking another signal? It's not a _pretty_ solution, but it should work across most kernel versions.
Linus -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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