On 04/20/17 09:51, Tyrel Datwyler wrote: > On 04/19/2017 09:43 PM, Frank Rowand wrote: > < snip > >> The call stack could easily be post-processed, for example using addr2line. >> Here is the call stack for when the refcount incremented to 23 from 22 (or >> more accurately, to 22 from 21): >> >> 0xc0d00e3c Line 857 of "init/main.c" >> 0xc03017d0 Line 792 of "init/main.c" >> 0xc0d3a234 Line 528 of "drivers/of/platform.c" >> 0xc0810684 Line 503 of "drivers/of/platform.c" >> 0xc081061c Line 267 of "include/linux/of.h" >> 0xc080d928 Line 815 of "drivers/of/base.c" >> >> Which ends up being this code: >> >> of_platform_default_populate_init() >> of_platform_default_populate() >> of_platform_populate() >> [[ of_find_node_by_path("/") ]] >> [[ of_find_node_opts_by_path(path, NULL) ]] >> of_node_get(of_root) >> >> Note that some functions can be left out of the ARM call stack, with >> a return going back more than one level. The functions in the call >> list above that are enclosed in '[[' and ']]' were found by source >> inspection in those cases. > > The same thing is encountered in ppc64 stack traces. I assume it is > generally inlining of small functions, but I've never actually verified > that theory. Probably should take the time to investigate, or just ask > someone. Yes, inlining small functions is one reason for this. Another case I often find is that when function A calls function B calls function C. If the final statement of function B is 'return C()' then there is no need for function C to return through function B, it can instead return directly to function A. (That is more a conceptual hand-waving of the idea, not the actual way the compiler implements it. Take this with a grain of salt, I'm not a compiler guy.) < snip > -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html