Hi, On Tue, Jan 25, 2022 at 5:35 PM Alexander Aring <aahringo@xxxxxxxxxx> wrote: > > Hi, > > On Mon, Jan 24, 2022 at 5:14 PM Paul E. McKenney <paulmck@xxxxxxxxxx> wrote: > > > > On Mon, Jan 24, 2022 at 04:36:55PM -0500, Alexander Aring wrote: > > > Hi, > > > > > > On Mon, Jan 24, 2022 at 3:23 PM Paul E. McKenney <paulmck@xxxxxxxxxx> wrote: > > > > > > > > On Mon, Jan 24, 2022 at 12:41:04PM -0500, Alexander Aring wrote: > > > > > Hi, > > > > > > > > > > On Mon, Jan 24, 2022 at 12:36 PM Alexander Aring <aahringo@xxxxxxxxxx> wrote: > > > > > > > > > > > > Hi, > > > > > > > > > > > > On Mon, Jan 24, 2022 at 12:21 PM Alexander Aring <aahringo@xxxxxxxxxx> wrote: > > > > > > > > > > > > > > Hi, > > > > > > > > > > > > > > On Mon, Jan 24, 2022 at 7:46 AM Dan Carpenter <dan.carpenter@xxxxxxxxxx> wrote: > > > > > > > > > > > > > > > > On Sun, Jan 23, 2022 at 01:41:52PM -0500, Alexander Aring wrote: > > > > > > > > > > > > > > > > > > I see also: > > > > > > > > > > > > > > > > > > fs/dlm/midcomms.c:213:1: sparse: sparse: symbol > > > > > > > > > '__srcu_struct_nodes_srcu' was not declared. Should it be static? > > > > > > > > > > > > > > > > > > > > > > > > > Why not just do this? (Untested. Maybe I don't understand?) > > > > > > > > > > > > > > > > diff --git a/include/linux/srcutree.h b/include/linux/srcutree.h > > > > > > > > index cb1f4351e8ba..a164089abec4 100644 > > > > > > > > --- a/include/linux/srcutree.h > > > > > > > > +++ b/include/linux/srcutree.h > > > > > > > > @@ -121,7 +121,7 @@ struct srcu_struct { > > > > > > > > #ifdef MODULE > > > > > > > > # define __DEFINE_SRCU(name, is_static) \ > > > > > > > > is_static struct srcu_struct name; \ > > > > > > > > - struct srcu_struct * const __srcu_struct_##name \ > > > > > > > > + is_static struct srcu_struct * const __srcu_struct_##name \ > > > > > > > > __section("___srcu_struct_ptrs") = &name > > > > > > > > #else > > > > > > > > # define __DEFINE_SRCU(name, is_static) \ > > > > > > > > > > > > > > > > > > > > > > I tried it and yes it will fix the issue and introduce another one > > > > > > > about "is_static struct srcu_struct * const __srcu_struct_##name" is > > > > > > > unused ("-Wunused-const-variable"). > > > > > > > I added a __maybe_unused after the introduced is_static and it seems > > > > > > > to fix the introduced issue, now it compiles and sparse is happy. I am > > > > > > > not sure if this is the right fix? > > > > > > > > > > > > it is obviously unused, but it has something to do with > > > > > > "__section("___srcu_struct_ptrs")" and during module loading it, I > > > > > > suppose, srcu tries to access it to find whatever needs to be > > > > > > registered? > > > > > > > > > > Sorry, but if this is true then it can't be declared as static... and > > > > > we are at the beginning again. > > > > > > > > Welcome to my world!!! ;-) > > > > > > > > More seriously, thank you for chasing this down. But would it work to > > > > add a declaration just before? > > > > > > > > > > only if I add an "extern" in front of the declaration before, so it looks like: > > > > > > extern struct srcu_struct * const __srcu_struct_##name; > > > > > > (compile and sparse tested only) > > > > If that works for everyone, it seems worth persuing. > > > > One way to test this is as follows: > > > > 1. Build a kernel with CONFIG_RCU_TORTURE_TEST=m. Boot this and > > type "modprobe rcutorture torture_type=srcu". > > > > If you want to stop the torture test, type "rmmod rcutorture". > > > > This will test DEFINE_SRCU() for the module case. > > > > I tested this case, I still need to do the 2. case. Sorry I am quite > busy with something else, but I am still working on it. > I did the 2. test successful...: "tools/testing/selftests/rcutorture/bin/kvm.sh --allcpus --duration 3 --configs 'SRCU-N' --trust-make" but I was required to hack it because my "qemu-system-x86_64" did not exist, it was "/usr/libexec/qemu-kvm" (it was able to run by just doing a symlink). I think I already cc'd the right people to report this issue (rcu subsystem)... I will send a patch for the export declaration soon as possible. - Alex