> Introduce DPDK per-lcore id variables, or lcore variables for short. > > An lcore variable has one value for every current and future lcore > id-equipped thread. > > The primary <rte_lcore_var.h> use case is for statically allocating > small, frequently-accessed data structures, for which one instance > should exist for each lcore. > > Lcore variables are similar to thread-local storage (TLS, e.g., C11 > _Thread_local), but decoupling the values' life time with that of the > threads. > > Lcore variables are also similar in terms of functionality provided by > FreeBSD kernel's DPCPU_*() family of macros and the associated > build-time machinery. DPCPU uses linker scripts, which effectively > prevents the reuse of its, otherwise seemingly viable, approach. > > The currently-prevailing way to solve the same problem as lcore > variables is to keep a module's per-lcore data as RTE_MAX_LCORE-sized > array of cache-aligned, RTE_CACHE_GUARDed structs. The benefit of > lcore variables over this approach is that data related to the same > lcore now is close (spatially, in memory), rather than data used by > the same module, which in turn avoid excessive use of padding, > polluting caches with unused data. > > Signed-off-by: Mattias Rönnblom <mattias.ronnb...@ericsson.com> > Acked-by: Morten Brørup <m...@smartsharesystems.com> > > --
Acked-by: Konstantin Ananyev <konstantin.anan...@huawei.com> > 2.34.1 >
