Messages in this thread | | | Date | Wed, 6 Oct 2010 14:51:02 -0700 | From | Greg KH <> | Subject | Re: [PATCH 1/4] Dynamic Debug: Introduce global fake module param module.ddebug - V4 |
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On Wed, Oct 06, 2010 at 11:40:52PM +0200, Thomas Renninger wrote: > On Wednesday 06 October 2010 11:16:04 pm Greg KH wrote: > > On Fri, Sep 24, 2010 at 02:28:28PM +0200, Thomas Renninger wrote: > > > Dynamic Debug allows enabling of pr_debug and dev_dbg messages at > > > runtime. This is controlled via /sys/kernel/debug/dynamic_debug/control. > > > One major drawback is that the whole initialization of a module cannot be > > > tracked, because ddebug is only aware of debug strings of loaded modules. > > > But this is the most interesting part... > > > > > > This patch introduces a fake module parameter module.ddebug(not shown in > > > /sys/module/*/parameters, thus it does not use any resources/memory). > > > > > > If a module passes ddebug as a module parameter (e.g. via module.ddebug > > > kernel boot param or via "modprobe module ddebug"), all debug strings of > > > this module get activated by issuing "module module_name +p" internally > > > (not via sysfs) when the module gets loaded. > > > > > > Possible enhancements for the future if ddebug might get extended with > > > further flags: > > > module.ddebug=flags > > > Then module.ddebug="p" would be the same as module.ddebug, but if there > > > is a "x" ddebug flag added, one could pass: > > > module.ddebug="xp" > > > which would result in such a dynamic debug query: > > > module module_name +xp > > > > > > Modules must not use "ddebug" as module parameter or it will get ignored. > > > If it's tried, a warning will show up at module load time that it will > > > get ignored (only works for not built-in modules). > > > > > > Tested with (additional added pr_debug messages): > > > options hp-wmi ddebug > > > in modprobe.conf > > > -> works and pr_debug messages issued at module initialization time show > > > up. Also "p" flag gets set for the whole hp-wmi module: > > > grep hp-wmi /sys/../dynamic_debug/control > > > also tested with compiled-in modules, e.g. pnp.ddebug and an additional > > > patch later in the patch series which instruments pnp code to work with > > > ddebug. > > > > I don't think you actually built this patch, as it dies: > > kernel/params.c: In function ‘parse_one’: > > kernel/params.c:114:2: error: ‘tmp’ undeclared (first use in this function) > > kernel/params.c:114:2: note: each undeclared identifier is reported only > > once for each function it appears in kernel/params.c: In function > > ‘destroy_params’: > > kernel/params.c:726:8: warning: unused variable ‘tmp’ > Strange, I added them to the latest SUSE factory kernel already and I didn't > do much more than copying (and slightly adjusting?). > > Can you give me a pointer to your git tree and branch you want the > patches based on, iirc I based them on latest Linus master branch.
Try them on top of linux-next, which has my patches in it.
Or use my quilt tree, which is on kernel.org (and in the MAINTAINERS file.)
thanks,
greg k-h -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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