[v7,0/8] Add stack library and new mempool handler

52226 mbox series

This patchset introduces a stack library, supporting both lock-based and
lock-free stacks, and a lock-free stack mempool handler.

The lock-based stack code is derived from the existing stack mempool handler,
and that handler is refactored to use the stack library.

The lock-free stack mempool handler is intended for usages where the rte
ring's "non-preemptive" constraint is not acceptable; for example, if the
application uses a mixture of pinned high-priority threads and multiplexed
low-priority threads that share a mempool.

Note that the lock-free algorithm relies on a 128-bit compare-and-swap[1],
so it is currently limited to the x86_64 platform.

This patchset is the successor to a patchset containing only the new mempool
handler[2].

[1] http://mails.dpdk.org/archives/dev/2019-April/129014.html
[2] http://mails.dpdk.org/archives/dev/2019-January/123555.html

---
v7:
- Add rte_branch_prediction.h include to rte_stack_std.h for unlikely()
- Add rte_compat.h include to rte_stack.h for __rte_experimental

v6:
- Add load-acquire fence to the lock-free push function
- Correct generic implementation's pop_elems 128b CAS success and failure
  memorder to match those in the C11 implementation.

v5:
- Add comment to explain padding in *_get_memsize() functions
- Prefix internal functions with '__'
- Use RTE_ASSERT for performance critical run-time checks
- Don't use __atomic_load in the C11 pop_elems function, and put an acquire
  thread fence at the start of the 2nd do-while loop
- Change pop_elems 128b CAS success memorder to RELEASE and failure memorder to
  RELAXED
- Change compile-time assertion to run for all 64-bit architectures
- Reorganize the code with standard and lock-free .c and .h files

v4:
- Fix 32-bit build error in test_stack.c by using %zu format specifier for
  size_t
- Rebase onto master

v3:
- Rebase patchset onto master (test/test/ -> app/test/)
- Fix rte_stack_std_push() segfault introduced in v2

v2:
- Reworked structure and function naming to use rte_stack_{std, lf}_...
- Updated to the latest rte_atomic128_cmp_exchange() interface.
- Rename STACK_F_NB -> RTE_STACK_F_LF.
- Remove rte_rmb() and rte_wmb() from the generic push and pop implementations.
  These are obviated by rte_atomic128_cmp_exchange()'s two memorder arguments.
- Edit stack_lib.rst text to 80 chars/line.
- Fix rte_stack.h doxygen formatting.
- Allocate popped_objs array from the heap
- Fix stack_thread_push_pop bug ("&t->sz" -> "t->sz")
- Remove unnecessary NULL check from test_stack_basic
- Properly terminate the name string in test_stack_name_length
- Add an empty array of struct rte_nb_lifo_elem elements
- In rte_nb_lifo_push(), retrieve the last element from __nb_lifo_pop()
- Split C11 implementation into a separate patchset

Gage Eads (8):
  stack: introduce rte stack library
  mempool/stack: convert mempool to use rte stack
  test/stack: add stack test
  test/stack: add stack perf test
  stack: add lock-free stack implementation
  stack: add C11 atomic implementation
  test/stack: add lock-free stack tests
  mempool/stack: add lock-free stack mempool handler

 MAINTAINERS                                     |   9 +-
 app/test/Makefile                               |   3 +
 app/test/meson.build                            |   7 +
 app/test/test_stack.c                           | 423 ++++++++++++++++++++++++
 app/test/test_stack_perf.c                      | 356 ++++++++++++++++++++
 config/common_base                              |   5 +
 doc/api/doxy-api-index.md                       |   1 +
 doc/api/doxy-api.conf.in                        |   1 +
 doc/guides/prog_guide/env_abstraction_layer.rst |  10 +
 doc/guides/prog_guide/index.rst                 |   1 +
 doc/guides/prog_guide/stack_lib.rst             |  83 +++++
 doc/guides/rel_notes/release_19_05.rst          |  13 +
 drivers/mempool/stack/Makefile                  |   3 +-
 drivers/mempool/stack/meson.build               |   6 +-
 drivers/mempool/stack/rte_mempool_stack.c       | 115 +++----
 lib/Makefile                                    |   2 +
 lib/librte_stack/Makefile                       |  29 ++
 lib/librte_stack/meson.build                    |  12 +
 lib/librte_stack/rte_stack.c                    | 196 +++++++++++
 lib/librte_stack/rte_stack.h                    | 260 +++++++++++++++
 lib/librte_stack/rte_stack_lf.c                 |  31 ++
 lib/librte_stack/rte_stack_lf.h                 | 106 ++++++
 lib/librte_stack/rte_stack_lf_c11.h             | 175 ++++++++++
 lib/librte_stack/rte_stack_lf_generic.h         | 164 +++++++++
 lib/librte_stack/rte_stack_pvt.h                |  34 ++
 lib/librte_stack/rte_stack_std.c                |  26 ++
 lib/librte_stack/rte_stack_std.h                | 121 +++++++
 lib/librte_stack/rte_stack_version.map          |   9 +
 lib/meson.build                                 |   2 +-
 mk/rte.app.mk                                   |   1 +
 30 files changed, 2132 insertions(+), 72 deletions(-)
 create mode 100644 app/test/test_stack.c
 create mode 100644 app/test/test_stack_perf.c
 create mode 100644 doc/guides/prog_guide/stack_lib.rst
 create mode 100644 lib/librte_stack/Makefile
 create mode 100644 lib/librte_stack/meson.build
 create mode 100644 lib/librte_stack/rte_stack.c
 create mode 100644 lib/librte_stack/rte_stack.h
 create mode 100644 lib/librte_stack/rte_stack_lf.c
 create mode 100644 lib/librte_stack/rte_stack_lf.h
 create mode 100644 lib/librte_stack/rte_stack_lf_c11.h
 create mode 100644 lib/librte_stack/rte_stack_lf_generic.h
 create mode 100644 lib/librte_stack/rte_stack_pvt.h
 create mode 100644 lib/librte_stack/rte_stack_std.c
 create mode 100644 lib/librte_stack/rte_stack_std.h
 create mode 100644 lib/librte_stack/rte_stack_version.map

03/04/2019 22:09, Gage Eads:
> v7:
> - Add rte_branch_prediction.h include to rte_stack_std.h for unlikely()
> - Add rte_compat.h include to rte_stack.h for __rte_experimental

There is another error when compiling for Arm:

lib/librte_stack/rte_stack.h:76:2: error:
	implicit declaration of function 'RTE_ASSERT'

> -----Original Message-----
> From: Thomas Monjalon [mailto:thomas@monjalon.net]
> Sent: Wednesday, April 3, 2019 3:40 PM
> To: Eads, Gage <gage.eads@intel.com>
> Cc: dev@dpdk.org; olivier.matz@6wind.com; arybchenko@solarflare.com;
> Richardson, Bruce <bruce.richardson@intel.com>; Ananyev, Konstantin
> <konstantin.ananyev@intel.com>; gavin.hu@arm.com;
> Honnappa.Nagarahalli@arm.com; nd@arm.com
> Subject: Re: [dpdk-dev] [PATCH v7 0/8] Add stack library and new mempool
> handler
> 
> 03/04/2019 22:09, Gage Eads:
> > v7:
> > - Add rte_branch_prediction.h include to rte_stack_std.h for unlikely()
> > - Add rte_compat.h include to rte_stack.h for __rte_experimental
> 
> There is another error when compiling for Arm:
> 
> lib/librte_stack/rte_stack.h:76:2: error:
> 	implicit declaration of function 'RTE_ASSERT'

Fix incoming. Looking through the rest of that header, I don't see any other externally defined macros/data structures/functions/etc. that would need another include.

Also note that v7's ci/Performance-Testing build fail (http://mails.dpdk.org/archives/test-report/2019-April/079261.html) is because dpdklab applied the patch on commit 3c45889189924067, which is older than the 128-bit CAS patch.