From: Pavel Machek <pavel@ucw.cz>
To: David Woodhouse <dwmw2@infradead.org>, linux-kernel@vger.kernel.org
Subject: Re: JFFS2 swsusp / signal cleanup.
Date: Sun, 5 Oct 2003 21:13:45 +0200 [thread overview]
Message-ID: <20031005191344.GA963@elf.ucw.cz> (raw)
In-Reply-To: <20031005171916.B21478@flint.arm.linux.org.uk>
Hi!
> > Is flush_signals() really so stupid to do? Goal was to make
> > modifications to code as simple as possible, and as most pieces do not
> > expect to be interrupted, pretending signal never happened seems like
> > good idea...
>
> What if that signal was necessary for the operation of the thread, and
> dropping it would cause a problem?
>
> Since you're effectively using signal handling to cause a false pending
> signal indication, surely the correct cleanup is to re-calculate the
> pending signal indication. That way, we won't be throwing away
> signals.
Should I do recalc_sigpending() instead of flush_signals(current)?
> I'm also wondering if there could be a problem with (ab)using TASK_STOPPED
> here - could a stopped task be woken prematurely and thereby sent spinning
> in refrigerator() by a non-stopped process sending a SIGCONT at just the
> right time?
>
> Maybe we want a TASK_FROZEN state to describe the "frozen, may not be woken
> by anything except thawing" state?
That would certainly be cleaner, but I think it would require
modifications all over the kernel...
That SIGCONT race... while() in refrigerator() should catch
that. Maybe we spin, but we go back to sleep pretty soon.
Pavel
--
When do you have a heart between your knees?
[Johanka's followup: and *two* hearts?]
next prev parent reply other threads:[~2003-10-05 19:14 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2003-10-04 11:25 JFFS2 swsusp / signal cleanup David Woodhouse
2003-10-05 16:11 ` Pavel Machek
2003-10-05 16:19 ` Russell King
2003-10-05 19:13 ` Pavel Machek [this message]
2003-10-05 20:07 ` David Woodhouse
2003-10-09 0:23 ` [pm] " Pavel Machek
2003-10-09 0:29 ` David Woodhouse
2003-10-09 9:24 ` Pavel Machek
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