Re: [PATCH RFC tip/core/rcu 0/4] Forbid static SRCU use in modules

On Sun, Apr 07, 2019 at 06:39:41AM -0700, Paul E. McKenney wrote: > On Sat, Apr 06, 2019 at 07:06:13PM -0400, Joel Fernandes wrote: [ . . . ] > > > diff --git a/include/asm-generic/vmlinux.lds.h > > > b/include/asm-generic/vmlinux.lds.h > > > index f8f6f04c4453..c2d919a1566e 100644 > > > --- a/include/asm-generic/vmlinux.lds.h > > > +++ b/include/asm-generic/vmlinux.lds.h > > > @@ -338,6 +338,10 @@ > > > KEEP(*(__tracepoints_ptrs)) /* Tracepoints: pointer array */ \ > > > __stop___tracepoints_ptrs = .; \ > > > *(__tracepoints_strings)/* Tracepoints: strings */ \ > > > + . = ALIGN(8); \ > > > + __start___srcu_struct = .; \ > > > + *(___srcu_struct_ptrs) \ > > > + __end___srcu_struct = .; \ > > > } \ > > > > This vmlinux linker modification is not needed. I tested without it and srcu > > torture works fine with rcutorture built as a module. Putting further prints > > in kernel/module.c verified that the kernel is able to find the srcu structs > > just fine. You could squash the below patch into this one or apply it on top > > of the dev branch. > > Good point, given that otherwise FORTRAN named common blocks would not > work. > > But isn't one advantage of leaving that stuff in the RO_DATA_SECTION() > macro that it can be mapped read-only? Or am I suffering from excessive > optimism? And to answer the other question, in the case where I am suffering from excessive optimism, it should be a separate commit. Please see below for the updated original commit thus far. And may I have your Tested-by?