| Message ID | 20181109231021.11658-5-linux@rasmusvillemoes.dk |
|---|---|
| State | Not Applicable, archived |
| Delegated to: | David Miller |
| Headers | show |
| Series | various dynamic_debug patches | expand |
On Sat, 2018-11-10 at 00:10 +0100, Rasmus Villemoes wrote: > Changes on x86-64 later in this series require that all struct _ddebug > descriptors in a translation unit uses distinct identifiers. Realize > that for net_dbg_ratelimited by generating such an identifier via > __UNIQUE_ID and pass that to an extra level of macros. > > No functional change. Why does this require an extra indirection _<macro>? > Cc: netdev@vger.kernel.org > Acked-by: Jason Baron <jbaron@akamai.com> > Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> > --- > include/linux/net.h | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/include/linux/net.h b/include/linux/net.h > index 651fca72286c..397243a25f56 100644 > --- a/include/linux/net.h > +++ b/include/linux/net.h > @@ -260,7 +260,7 @@ do { \ > #define net_info_ratelimited(fmt, ...) \ > net_ratelimited_function(pr_info, fmt, ##__VA_ARGS__) > #if defined(CONFIG_DYNAMIC_DEBUG) > -#define net_dbg_ratelimited(fmt, ...) \ > +#define _net_dbg_ratelimited(descriptor, fmt, ...) \ > do { \ > DEFINE_DYNAMIC_DEBUG_METADATA(descriptor, fmt); \ > if (DYNAMIC_DEBUG_BRANCH(descriptor) && \ > @@ -268,6 +268,8 @@ do { \ > __dynamic_pr_debug(&descriptor, pr_fmt(fmt), \ > ##__VA_ARGS__); \ > } while (0) > +#define net_dbg_ratelimited(fmt, ...) \ > + _net_dbg_ratelimited(__UNIQUE_ID(ddebug), fmt, ##__VA_ARGS__) > #elif defined(DEBUG) > #define net_dbg_ratelimited(fmt, ...) \ > net_ratelimited_function(pr_debug, fmt, ##__VA_ARGS__)
On 10/11/2018 00.22, Joe Perches wrote: > On Sat, 2018-11-10 at 00:10 +0100, Rasmus Villemoes wrote: >> Changes on x86-64 later in this series require that all struct _ddebug >> descriptors in a translation unit uses distinct identifiers. Realize >> that for net_dbg_ratelimited by generating such an identifier via >> __UNIQUE_ID and pass that to an extra level of macros. >> >> No functional change. > > Why does this require an extra indirection _<macro>? > Because the identifier used in the >> DEFINE_DYNAMIC_DEBUG_METADATA(descriptor, fmt); line must be the same as the one in the >> if (DYNAMIC_DEBUG_BRANCH(descriptor) && line. That identifier used to be simply "descriptor", with C scope rules making that ok. But because of the asm games I'm playing later, I need to generate a fresh identifier for each instance. That identifier must be referenced in two places in the C source - hence the need to use an extra level of macros to have the __UNIQUE_ID() expanded before _net_dbg_ratelimited gets expanded. More or less every use of __UNIQUE_ID requires such an extra level (because one very rarely needs to use an identifier exactly once - the point of giving stuff a name is to refer to it again.) Rasmus
diff --git a/include/linux/net.h b/include/linux/net.h index 651fca72286c..397243a25f56 100644 --- a/include/linux/net.h +++ b/include/linux/net.h @@ -260,7 +260,7 @@ do { \ #define net_info_ratelimited(fmt, ...) \ net_ratelimited_function(pr_info, fmt, ##__VA_ARGS__) #if defined(CONFIG_DYNAMIC_DEBUG) -#define net_dbg_ratelimited(fmt, ...) \ +#define _net_dbg_ratelimited(descriptor, fmt, ...) \ do { \ DEFINE_DYNAMIC_DEBUG_METADATA(descriptor, fmt); \ if (DYNAMIC_DEBUG_BRANCH(descriptor) && \ @@ -268,6 +268,8 @@ do { \ __dynamic_pr_debug(&descriptor, pr_fmt(fmt), \ ##__VA_ARGS__); \ } while (0) +#define net_dbg_ratelimited(fmt, ...) \ + _net_dbg_ratelimited(__UNIQUE_ID(ddebug), fmt, ##__VA_ARGS__) #elif defined(DEBUG) #define net_dbg_ratelimited(fmt, ...) \ net_ratelimited_function(pr_debug, fmt, ##__VA_ARGS__)