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Date: Mon, 7 Jul 2003 08:45:52 -0700
From: Alfred Perlstein <bright@mu.org>
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cc: David Xu <davidxu@viatech.com.cn>
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Subject: Re: cvs commit: src/lib/libpthread/thread thr_attr_get_np.c
	thr_cancel.c thr_getschedparam.c thr_join.c thr_mutex_prioceiling.c
	thr_sigaction.c thr_sigmask.c thr_sigpending.c thr_sigsuspend.c
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* Daniel Eischen <eischen@vigrid.com> [030707 05:56] wrote:
> 
> The code questioned is when we are not in the UTS but have
> a current thread.  We block upcalls when threads are in
> critical regions (so the thread won't be swapped out
> onto a different KSE by the kernel).  In those regions,
> we can page fault and the KSE will not run again until
> the page is present (just like above), but we don't want
> a SEGV caused by an application parameter.  If we get
> a SEGV, the KSE will not run again (because upcalls
> are blocked) and the application will not get the signal.

Thanks David and Dan, this makes a sense now.  (David's earlier
explanation was also great.)