On 5/21/2019 3:31 PM, Stephen Hemminger wrote: > On Tue, 21 May 2019 08:01:53 +0000 > "Van Haaren, Harry" <harry.van.haa...@intel.com> wrote: > >>> -----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.
+1 to define '__rte_cold' [1] in 'lib/librte_eal/common/include/rte_common.h' as defined other similar compiler attributes there. [1] or '__rte_attribute_cold' but all other attribute defines are missing 'attribute' keyword, so I think can be skipped here as well >> >> -Harry > > I just cloned what was already on rte_log. >
