On Thu, Aug 29, 2019 at 09:44:04PM +0530, Amit Kucheria wrote: > On Thu, Aug 29, 2019 at 8:49 PM Daniel Thompson > <daniel.thompson@xxxxxxxxxx> wrote: > > > > On Thu, Aug 29, 2019 at 07:58:45PM +0530, Amit Kucheria wrote: > > > On Thu, Aug 29, 2019 at 7:35 PM Daniel Thompson > > > <daniel.thompson@xxxxxxxxxx> wrote: > > > > > > > > On Tue, Aug 27, 2019 at 05:43:59PM +0530, Amit Kucheria wrote: > > > > > Printing the function name when enabling debugging makes logs easier to > > > > > read. > > > > > > > > > > Signed-off-by: Amit Kucheria <amit.kucheria@xxxxxxxxxx> > > > > > Reviewed-by: Stephen Boyd <swboyd@xxxxxxxxxxxx> > > > > > Reviewed-by: Daniel Lezcano <daniel.lezcano@xxxxxxxxxx> > > > > > > > > This should need to be manually added at each call site; it is already > > > > built into the logging system (the f flag for dynamic debug)? > > > > > > I assume you meant "shouldn't". > > > > Quite so. Sorry about that. > > > > > I haven't yet integrated dynamic debug into my daily workflow. > > > > > > Last time I looked at it, it was a bit bothersome to use because I > > > needed to lookup exact line numbers to trigger useful information. And > > > those line numbers constantly keep changing as I work on the driver, > > > so it was a bit painful to script. Not to mention the syntax to frob > > > the correct files in debugfs to enable this functionality. > > > > > > As opposed to this, adding the following to the makefile is so easy. :-) > > > > > > CFLAGS_tsens-common.o := -DDEBUG > > > > > > Perhaps I am using it all wrong? How would I go about using dynamic > > > debug instead of this patch? > > > > Throwing dyndbg="file <fname>.c +pf" onto the kernel command line is a > > good start (+p enables debug level prints, +f causes messages to include > > the function name). > > That's useful to know. > > $ git grep __func__ | wc -l > 30914 > > Want to send some patches? :-) I know. Sad isn't it? To be fair plenty of patches already circulate tidying up this sort of thing (along with the removal of inane messages such as informing us that a function run). > > When the C files map to module names (whether the modules are actually > > built-in or not) then <module>.dyndbg=+pf is a bit cleaner and allows > > you to debug the whole of a driver without how it is decomposed into > > files. > > And if changing the kernel cmdline options isn't possible or is inconvenient? Architectures where this problem offer CONFIG_CMDLINE_FORCE meaning if you are already building a custom kernel you can override whatever cmdline the bootloader gives you. > > There are (many) other controls to play with[1] but the above should be > > sufficient to simulate -DDEBUG . > > The "hard" bit is explicitly poking the line number in a file to > activate a paricular pr_dbg statement. Even if I scripted it, those > lines numbers keep changing in an actively developed driver. Line numbers? Nothing I suggested contained a line number. Daniel. > > Somehow, I've always felt dyndbg was more useful to debug a production > system where recompiling the kernel wasn't an option e.g. reporting an > issue back to a distro-kernel vendor. > > > Daniel. > > > > [1] > > https://www.kernel.org/doc/html/latest/admin-guide/dynamic-debug-howto.html
