Re: which signal is sent to freeze process?

[Rafael J. Wysocki]

On Monday, 23 July 2007 21:52, Manfred Spraul wrote:
> Rafael wrote:
> > On Monday, 23 July 2007 20:38, Agarwal, Lomesh wrote:
> > > The other problem I am facing that read from socket returns with ENODATA
> > > when resuming. any ideas?
> >
> > It's of similar kind: the system call checks signal_pending(current) and exit
> > with an error if that's true.
> >
> > Well, I'm afraid we can't place try_to_freeze() in every system call that
> > does something like that ...
> >   
> I don't understand why the poll() system call returns to user space. 
> poll() uses ERESTARTNOHAND, thus it should not return to user space.
> Any ideas why ERESTARTNOHAND doesn't work?

Well, look at the code in fs/select.c:do_poll() .  If signal_pending(current)
is true, the main loop breaks and count is returned to do_sys_poll().  If
zero is returned and signal_pending(current) is still true, do_sys_poll()
returns -EINTR.

Greetings,
Rafael


-- 
"Premature optimization is the root of all evil." - Donald Knuth
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