[RFC,v6,0/6] Lcore variables

Message ID 20240506082721.120666-1-mattias.ronnblom@ericsson.com (mailing list archive)
Headers
Series Lcore variables |

Message

Mattias Rönnblom May 6, 2024, 8:27 a.m. UTC
This RFC presents a new API <rte_lcore_var.h> for static per-lcore id
data allocation.

Please refer to the <rte_lcore_var.h> API documentation for both a
rationale for this new API, and a comparison to the alternatives
available.

The adoption of this API would affect many different DPDK modules, but
the author updated only a few, mostly to serve as examples in this
RFC, and to iron out some, but surely not all, wrinkles in the API.

The question on how to best allocate static per-lcore memory has been
up several times on the dev mailing list, for example in the thread on
"random: use per lcore state" RFC by Stephen Hemminger.

Lcore variables are surely not the answer to all your per-lcore-data
needs, since it only allows for more-or-less static allocation. In the
author's opinion, it does however provide a reasonably simple and
clean and seemingly very much performant solution to a real problem.

One thing is unclear to the author is how this API relates to a
potential future per-lcore dynamic allocator (e.g., a per-lcore heap).

Mattias Rönnblom (6):
  eal: add static per-lcore memory allocation facility
  eal: add lcore variable test suite
  random: keep PRNG state in lcore variable
  power: keep per-lcore state in lcore variable
  service: keep per-lcore state in lcore variable
  eal: keep per-lcore power intrinsics state in lcore variable

 app/test/meson.build                  |   1 +
 app/test/test_lcore_var.c             | 432 ++++++++++++++++++++++++++
 config/rte_config.h                   |   1 +
 doc/api/doxy-api-index.md             |   1 +
 lib/eal/common/eal_common_lcore_var.c |  69 ++++
 lib/eal/common/meson.build            |   1 +
 lib/eal/common/rte_random.c           |  28 +-
 lib/eal/common/rte_service.c          | 115 +++----
 lib/eal/include/meson.build           |   1 +
 lib/eal/include/rte_lcore_var.h       | 384 +++++++++++++++++++++++
 lib/eal/version.map                   |   3 +
 lib/eal/x86/rte_power_intrinsics.c    |  17 +-
 lib/power/rte_power_pmd_mgmt.c        |  34 +-
 13 files changed, 1000 insertions(+), 87 deletions(-)
 create mode 100644 app/test/test_lcore_var.c
 create mode 100644 lib/eal/common/eal_common_lcore_var.c
 create mode 100644 lib/eal/include/rte_lcore_var.h