On Fri, May 29, 2020 at 12:16:31AM -0400, Valdis Klētnieks wrote: > commit 9088b449814f788d24f35a5840b6b2c2a23cd32a > Author: Paul E. McKenney <paulmck@xxxxxxxxxx> > Date: Mon May 25 17:22:24 2020 -0700 > > refperf: Provide module parameter to specify number of experiments > > changes this line of code (line 389) > > - reader_tasks[exp].result_avg = 1000 * process_durations(exp) / ((exp + 1) * loops); > + result_avg[exp] = 1000 * process_durations(nreaders) / (nreaders * loops); > > On a 32-bit ARM make allmodconfig with gcc 8.3, this results in: > > ERROR: modpost: "__aeabi_uldivmod" [kernel/rcu/refperf.ko] undefined! > make[1]: *** [scripts/Makefile.modpost:103: __modpost] Error 1 > > I admit not understanding why the original line of code worked and the new one doesn't. > Maybe gcc is smarter/dumber about the ranges of 'exp' and 'nreaders' than we thought? I was surprised by that as well, but yesterday I took the lazy way out by making this module depend on 64BIT. (0day reported a similar issue on m68k.) So this issue should no longer show up. ;-) Thanx, Paul
