On Fri, Feb 22, 2019 at 12:53 PM Thiago Jung Bauermann <bauerman@xxxxxxxxxxxxx> wrote: > > > Frank Rowand <frowand.list@xxxxxxxxx> writes: > > > On 2/19/19 10:34 PM, Brendan Higgins wrote: > >> On Mon, Feb 18, 2019 at 12:02 PM Frank Rowand <frowand.list@xxxxxxxxx> wrote: > >> <snip> > >>> I have not read through the patches in any detail. I have read some of > >>> the code to try to understand the patches to the devicetree unit tests. > >>> So that may limit how valid my comments below are. > >> > >> No problem. > >> > >>> > >>> I found the code difficult to read in places where it should have been > >>> much simpler to read. Structuring the code in a pseudo object oriented > >>> style meant that everywhere in a code path that I encountered a dynamic > >>> function call, I had to go find where that dynamic function call was > >>> initialized (and being the cautious person that I am, verify that > >>> no where else was the value of that dynamic function call). With > >>> primitive vi and tags, that search would have instead just been a > >>> simple key press (or at worst a few keys) if hard coded function > >>> calls were done instead of dynamic function calls. In the code paths > >>> that I looked at, I did not see any case of a dynamic function being > >>> anything other than the value it was originally initialized as. > >>> There may be such cases, I did not read the entire patch set. There > >>> may also be cases envisioned in the architects mind of how this > >>> flexibility may be of future value. Dunno. > >> > >> Yeah, a lot of it is intended to make architecture specific > >> implementations and some other future work easier. Some of it is also > >> for testing purposes. Admittedly some is for neither reason, but given > >> the heavy usage elsewhere, I figured there was no harm since it was > >> all private internal usage anyway. > >> > > > > Increasing the cost for me (and all the other potential code readers) > > to read the code is harm. > > Dynamic function calls aren't necessary for arch-specific > implementations either. See for example arch_kexec_image_load() in > kernel/kexec_file.c, which uses a weak symbol that is overriden by > arch-specific code. Not everybody likes weak symbols, so another > alternative (which admitedly not everybody likes either) is to use a > macro with the name of the arch-specific function, as used by > arch_kexec_post_alloc_pages() in <linux/kexec.h> for instance. I personally have a strong preference for dynamic function calls over weak symbols or macros, but I can change it if it really makes anyone's eyes bleed.
