Date: Wed, 18 Jun 2003 09:33:18 -0400 (EDT) From: Robert Watson <rwatson@freebsd.org> To: Poul-Henning Kamp <phk@phk.freebsd.dk> Cc: arch@freebsd.org Subject: Re: marking normal sleep identifiers as such. Message-ID: <Pine.NEB.3.96L.1030618092937.4523A-100000@fledge.watson.org> In-Reply-To: <36655.1055917248@critter.freebsd.dk>
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On Wed, 18 Jun 2003, Poul-Henning Kamp wrote: > Now that we have a bunch of kernel threads which participate in the > running of the system, I find that it is a tad more time consuming to > figure out what the state of a crashed or hung system is. > > So I was wondering if we should instigate a simple convention for the > sleep identifiers to make it easier to spot, or rather: ignore, kthreads > which are in their normal idle position. > > Since thread names are longer than the space we have in ps(1) output > using the thread name is not feasible solution. > > I notice that the interrupt threads all seem to sleep on "-", and all > things considered, I like that. > > Should we adopt that as our convention ? I agree with the concern -- I've similarly noticed an increase in the amount of time I spend diagnosing apparent deadlocks as I attempt to determine if kernel threads are simply idle, or stuck on locks. I don't really mind what the convention is; "-" is probably as good as any. Another possible convention would be to name the state fooidle -- i.e., pageridle, acpiidle, ... Given that the purpose of the thread is documented in the thread name, generally, this is probably overkill and unnecessarilly extends the number and length of strings involved. A final option that comes to mind would be simply to call the state "idle". One disadvantage of changing to a common name with no distinct string is that it makes it quite a bit harder to track down the sleep call in the kernel; you can no longer glimpse/grep on the state to find the stage in the thread event loop you've reached, which would be one reason to prefer a fooidle approach. Robert N M Watson FreeBSD Core Team, TrustedBSD Projects robert@fledge.watson.org Network Associates Laboratories
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