Date: Thu, 7 Oct 2004 08:39:54 +0930 From: Greg 'groggy' Lehey <grog@FreeBSD.org> To: Roman Kurakin <rik@cronyx.ru> Cc: hackers@FreeBSD.org Subject: Re: Printing from kernel Message-ID: <20041006230954.GO1350@wantadilla.lemis.com> In-Reply-To: <41645625.3020209@cronyx.ru> References: <41645625.3020209@cronyx.ru>
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--MM5RgFPKyuP3gDcV Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Thursday, 7 October 2004 at 0:31:33 +0400, Roman Kurakin wrote: > Hi, > > I have some problems with printing from kernel. > At first I think that my problems was cause I use printf, > but changed all of them to log cause it safe to use from > interrupt handlers. The situation become better but I still > observe system lockup in case I output some debug information > from my driver. About the only thing I can think is that you're doing this in some area where it's unsafe to print, probably holding a lock that's needed in the print routines. > Also I have some problems with system console via com > port. Instead of messages from kernel I see the first letter > of the month name. > > Could anybody comment my observation? Without more detail, it's impossible to help. > Does anybody saw anything like this? No. printf() is widely used in the kernel. > Oh, I forget to say I observe that with both Current > and Releng5, SMP. Also I can't trigger NMI so I can't see the > point of lockup. Take a look at your code and check what locks you're holding. Also, if this is only for debugging, you should be using the kernel debugger. Greg -- See complete headers for address and phone numbers. --MM5RgFPKyuP3gDcV Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.6 (FreeBSD) iD8DBQFBZHtCIubykFB6QiMRAgrXAJ40ABfpO+8zaPfgAUU+o/FfsJLlOACgofdD U5eauZVejXjRf612kQW/zQU= =xUSo -----END PGP SIGNATURE----- --MM5RgFPKyuP3gDcV--
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