> -----Original Message----- > From: dev [mailto:dev-boun...@dpdk.org] On Behalf Of Stephen Hemminger > Sent: Monday, May 20, 2019 11:52 PM > To: adrien.mazarg...@6wind.com > Cc: dev@dpdk.org; Stephen Hemminger <step...@networkplumber.org> > Subject: [dpdk-dev] [PATCH] rte_flow: mark rte_flow_error_set as cold > > A minor optimization that save a few cycles during flow setup. > > Use the GCC cold attribute for the rte_flow_error_set function. > This attribute implicitly marks all code paths that arrive at > this function as unlikely.
Interesting - wasn't aware this is what the "cold" attribute does. > lib/librte_ethdev/rte_flow.h | 8 +++++++- > 1 file changed, 7 insertions(+), 1 deletion(-) > > diff --git a/lib/librte_ethdev/rte_flow.h b/lib/librte_ethdev/rte_flow.h > index 63f84fca65c4..dc821be43f19 100644 > --- a/lib/librte_ethdev/rte_flow.h > +++ b/lib/librte_ethdev/rte_flow.h > @@ -2591,7 +2591,13 @@ rte_flow_error_set(struct rte_flow_error *error, > int code, > enum rte_flow_error_type type, > const void *cause, > - const char *message); > + const char *message) > +#ifdef __GNUC__ > +#if (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ > 2)) > + __attribute__((cold)) > +#endif > +#endif > + ; Would it be worth making an __rte_attribute_cold or similar? Less in-place #ifdefs and there are probably other locations in DPDK that would also benefit from such an annotation. -Harry
