On Fri, Aug 23, 2019 at 04:44:09PM +0000, Michael Kelley wrote: > From: Branden Bonaby <brandonbonaby94@xxxxxxxxx> Sent: Thursday, August 22, 2019 8:39 PM > > > > diff --git a/drivers/hv/connection.c b/drivers/hv/connection.c > > > > index 09829e15d4a0..c9c63a4033cd 100644 > > > > --- a/drivers/hv/connection.c > > > > +++ b/drivers/hv/connection.c > > > > @@ -357,6 +357,9 @@ void vmbus_on_event(unsigned long data) > > > > > > > > trace_vmbus_on_event(channel); > > > > > > > > +#ifdef CONFIG_HYPERV_TESTING > > > > + hv_debug_delay_test(channel, INTERRUPT_DELAY); > > > > +#endif /* CONFIG_HYPERV_TESTING */ > > > > > > You are following Vitaly's suggestion to use #ifdef's so no code is > > > generated when HYPERV_TESTING is not enabled. However, this > > > direct approach to using #ifdef's really clutters the code and makes > > > it harder to read and follow. The better approach is to use the > > > #ifdef in the include file where the functions are defined. If > > > HYPERV_TESTING is not enabled, provide a #else that defines > > > the function with an empty implementation for which the compiler > > > will generate no code. An as example, see the function definition > > > for hyperv_init() in arch/x86/include/asm/mshyperv.h. There are > > > several functions treated similarly in that include file. > > > > > > > I checked out the code in arch/x86/include/asm/mshyperv.h, after > > thinking about it, I'm wondering if it would be better just to have > > two files one called hv_debugfs.c and the other hyperv_debugfs.h. > > I could put the code definitions in hv_debugfs.c and at the top > > include the hyperv_debugfs.h file which would house the declarations > > of these functions under the ifdef. Then like you alluded too use > > an #else statement that would have the null implementations of the > > above functions. Then put an #include "hyperv_debugfs.h" in the > > hyperv_vmbus.h file. I figured instead of putting the code directly > > into the vmbus_drv.c file it might be best to put them in a seperate > > file like hv_debugfs.c. This way when we start adding more tests we > > don't bloat the vmbus_drv.c file unnecessarily. The hv_debugfs.c > > file would have the #ifdef CONFIG_HYPERV_TESTING at the top so if > > its not enabled those null implementations in "hyperv_debugfs.h" > > woud kick in anywhere that included the hyperv_vmbus.h file which > > is what we want. > > > > what do you think? > > > > I'll preface my comments by saying that how code gets structured > into files is always a bit of a judgment call. The goal is to group code > into sensible chunks to make it easy to understand and to make it > easy to modify and extend later. The latter is a prediction about the > future, which may or may not be accurate. For the former, what's > "easy to understand," is often in the eye of the beholder. So you may > get different opinions from different reviewers. > > That said, I like the idea of a separate hv_debugfs.c file to contain > the implementation of the various functions you have added to > provide the fuzzing capability. I'm less convinced about the value > of a separate hyperv_debugfs.h file. I think you have one big > #ifdef CONFIG_HYPERV_TESTING followed by the declarations of > the functions in hv_debugfs.c, followed by #else and null > implementations of those functions. This is 20 lines of code or so, > and could easily go in hyperv_vmbus.h. > > For the new hv_debugfs.c, you can avoid the need for > #ifdef CONFIG_HYPERV_TESTING by modifying the Makefile in > drivers/hv so that hv_debugfs.o is built only if CONFIG_HYPERV_TESTING > is defined. Look at the current Makefile to see how this is done > with CONFIG_HYPERV_UTILS and CONFIG_HYPERV_BALLOON. > > Michael > I see, that does make sense, I'll go ahead and add these changes. thanks branden bonaby
