Date: Tue, 5 Jun 2012 09:47:48 -0400 From: John Baldwin <jhb@freebsd.org> To: freebsd-arch@freebsd.org Cc: Dag-Erling =?utf-8?q?Sm=C3=B8rgrav?= <des@des.no> Subject: Re: KTR_SPAREx Message-ID: <201206050947.48750.jhb@freebsd.org> In-Reply-To: <86bokyvtc2.fsf@ds4.des.no>
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On Tuesday, June 05, 2012 8:25:33 am Dag-Erling Smørgrav wrote: > Most of this is in device drivers, which should use KTR_DEV. There is > one major use of KTR_SPAREx in common code: KTR_SPARE2 is used for clock > events. It is also used incorrectly by the sparc64 pmap core (there is > a separate KTR_PMAP for that). > > I suggest that we > > 1) rename one of the spare KTRs to KTR_CLOCK and use that for clock > events. I already have a patch for that. > > 2) eliminate all other use of KTR_SPARE[0-9] in non-device code. I > think the existing KTRs should already cover most cases. > > 3) modify device drivers to use KTR_DEV for events that aren't covered > by existing, more specific KTRs, which is almost none. For instance, > there is no reason why cxgb shouldn't just use KTR_NET. There is a reason in that you may want to only get those specific events and not drown in noise from the network stack itself for example. What I tend to do in drivers where I want to do this is have something like this: #if 0 #define KTR_CXGB KTR_DEV #else #define KTR_CXGB 0 #endif and then use 'KTR_CXGB' instead of 'KTR_DEV' or 'KTR_SPARE2' explicitly. It looks like most of the drivers are already doing this and if it is #if 0'd by default, then I would just let them be. The two CTR()s in tom/cxgb_cpl_io.c should probably be using KTR_TOM instead of KTR_SPARE2 directly. As a long term goal I would like to switch to using individual ints instead of a 32-bit bitmask as that would let us add new trace classes with ease. I haven't figured out a design for that that I fully like yet however. -- John Baldwinhome | help
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