Date: Thu, 20 Dec 2001 13:15:26 -0800 (PST) From: John Baldwin <jhb@FreeBSD.org> To: Julian Elischer <julian@elischer.org> Cc: Alfred Perlstein <bright@mu.org>, Poul-Henning Kamp <phk@freebsd.org>, arch@freebsd.org Subject: Re: Kernel stack size and stacking: do we have a problem ? Message-ID: <XFMail.011220131526.jhb@FreeBSD.org> In-Reply-To: <Pine.BSF.4.21.0112201244380.46573-100000@InterJet.elischer.org>
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On 20-Dec-01 Julian Elischer wrote: > > > On Thu, 20 Dec 2001, John Baldwin wrote: > >> >> On 20-Dec-01 Julian Elischer wrote: >> > basically yes, after N levels, switch to what netisr() does. >> > then you get another N levels :-) The reason I hadn't checked it in is >> > because I was thinking about whether it should be N levels or N bytes of >> > stack used.... >> >> It should be based on how much stack room is left. > yes that is what I was thinking.. > > curthread->kstack is the last valid location so it's actually very easy. > > But I wanted to actually 'drop' the packet if it went through > a total of some maximum number of nodes allowed.. > e.g. 64.. I can't imagine a practical application that requires a packet > to go through 64 successive layers of en(de)capsulation.. :-) > > It may be worth keeping a counter AND doing the stack check. The counter is something that is netgraph specific. The idea of checking the stack and pushing the work off onto a thread if we run out of room isn't. :) -- John Baldwin <jhb@FreeBSD.org> <>< http://www.FreeBSD.org/~jhb/ "Power Users Use the Power to Serve!" - http://www.FreeBSD.org/ To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-arch" in the body of the message
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