Hello, On Tue, Nov 26, 2013 at 11:37:03AM +0800, Wanlong Gao wrote: > If kernel config CONFIG_DEBUG_FORCE_WEAK_PER_CPU=y, then the sparse will report non-static > warnings like following: > > > /git/linux/fs/inode.c:74:8: warning: symbol 'nr_inodes' was not declared. Should it be static? > > /git/linux/fs/inode.c:75:8: warning: symbol 'nr_unused' was not declared. Should it be static? > > > > $ vi +74 fs/inode.c > > 73 > > 74 static DEFINE_PER_CPU(unsigned long, nr_inodes); > > 75 static DEFINE_PER_CPU(unsigned long, nr_unused); > > 76 Hmmm, so, if FORCE_WEAK_PER_CPU is set or the arch needs WEAK_PER_CPU, DEFINE_PER_CPU() explodes into mind-bending series of definitions to ensure that the symbol is globally unique to avoid breaking weak decl requirements on a few archs. In the process static is dropped from the actual declaration and it's apparently missing extern decl in front of it. Does the following patch make it go away? Thanks. diff --git a/include/linux/percpu-defs.h b/include/linux/percpu-defs.h index 57e890a..8c490cc 100644 --- a/include/linux/percpu-defs.h +++ b/include/linux/percpu-defs.h @@ -69,6 +69,7 @@ __PCPU_DUMMY_ATTRS char __pcpu_scope_##name; \ extern __PCPU_DUMMY_ATTRS char __pcpu_unique_##name; \ __PCPU_DUMMY_ATTRS char __pcpu_unique_##name; \ + extern __typeof__(type) name; \ __PCPU_ATTRS(sec) PER_CPU_DEF_ATTRIBUTES __weak \ __typeof__(type) name #else -- To unsubscribe from this list: send the line "unsubscribe linux-sparse" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
