Re: [dpdk-dev] [PATCH v2 2/2] mempool/nb_stack: add non-blocking stack mempool

["Eads, Gage" <gage.eads@intel.com>]

> -----Original Message-----
> From: Gavin Hu (Arm Technology China) [mailto:Gavin.Hu@arm.com]
> Sent: Thursday, January 17, 2019 2:06 AM
> To: Eads, Gage <gage.eads@intel.com>; dev@dpdk.org
> Cc: olivier.matz@6wind.com; arybchenko@solarflare.com; Richardson, Bruce
> <bruce.richardson@intel.com>; Ananyev, Konstantin
> <konstantin.ananyev@intel.com>; Honnappa Nagarahalli
> <Honnappa.Nagarahalli@arm.com>; Ruifeng Wang (Arm Technology China)
> <Ruifeng.Wang@arm.com>; Phil Yang (Arm Technology China)
> <Phil.Yang@arm.com>
> Subject: RE: [dpdk-dev] [PATCH v2 2/2] mempool/nb_stack: add non-blocking
> stack mempool
> 
> 
> > -----Original Message-----
> > From: dev <dev-bounces@dpdk.org> On Behalf Of Gage Eads
> > Sent: Wednesday, January 16, 2019 6:33 AM
> > To: dev@dpdk.org
> > Cc: olivier.matz@6wind.com; arybchenko@solarflare.com;
> > bruce.richardson@intel.com; konstantin.ananyev@intel.com
> > Subject: [dpdk-dev] [PATCH v2 2/2] mempool/nb_stack: add non-blocking
> > stack mempool
> >
> > This commit adds support for non-blocking (linked list based) stack
> > mempool handler. The stack uses a 128-bit compare-and-swap
> > instruction, and thus is limited to x86_64. The 128-bit CAS atomically
> > updates the stack top pointer and a modification counter, which
> > protects against the ABA problem.
> >
> > In mempool_perf_autotest the lock-based stack outperforms the non-
> > blocking handler*, however:
> > - For applications with preemptible pthreads, a lock-based stack's
> >   worst-case performance (i.e. one thread being preempted while
> >   holding the spinlock) is much worse than the non-blocking stack's.
> > - Using per-thread mempool caches will largely mitigate the performance
> >   difference.
> >
> > *Test setup: x86_64 build with default config, dual-socket Xeon
> > E5-2699 v4, running on isolcpus cores with a tickless scheduler. The
> > lock-based stack's rate_persec was 1x-3.5x the non-blocking stack's.
> >
> > Signed-off-by: Gage Eads <gage.eads@intel.com>
> > ---
> >  MAINTAINERS                                        |   4 +
> >  config/common_base                                 |   1 +
> >  doc/guides/prog_guide/env_abstraction_layer.rst    |   5 +
> >  drivers/mempool/Makefile                           |   3 +
> >  drivers/mempool/meson.build                        |   5 +
> >  drivers/mempool/nb_stack/Makefile                  |  23 ++++
> >  drivers/mempool/nb_stack/meson.build               |   4 +
> >  drivers/mempool/nb_stack/nb_lifo.h                 | 147
> > +++++++++++++++++++++
> >  drivers/mempool/nb_stack/rte_mempool_nb_stack.c    | 125
> > ++++++++++++++++++
> >  .../nb_stack/rte_mempool_nb_stack_version.map      |   4 +
> >  mk/rte.app.mk                                      |   7 +-
> >  11 files changed, 326 insertions(+), 2 deletions(-)  create mode
> > 100644 drivers/mempool/nb_stack/Makefile  create mode 100644
> > drivers/mempool/nb_stack/meson.build
> >  create mode 100644 drivers/mempool/nb_stack/nb_lifo.h
> >  create mode 100644 drivers/mempool/nb_stack/rte_mempool_nb_stack.c
> >  create mode 100644
> > drivers/mempool/nb_stack/rte_mempool_nb_stack_version.map
> >
> > diff --git a/MAINTAINERS b/MAINTAINERS index 470f36b9c..5519d3323
> > 100644
> > --- a/MAINTAINERS
> > +++ b/MAINTAINERS
> > @@ -416,6 +416,10 @@ M: Artem V. Andreev <artem.andreev@oktetlabs.ru>
> >  M: Andrew Rybchenko <arybchenko@solarflare.com>
> >  F: drivers/mempool/bucket/
> >
> > +Non-blocking stack memory pool
> > +M: Gage Eads <gage.eads@intel.com>
> > +F: drivers/mempool/nb_stack/
> > +
> >
> >  Bus Drivers
> >  -----------
> > diff --git a/config/common_base b/config/common_base index
> > 964a6956e..8a51f36b1 100644
> > --- a/config/common_base
> > +++ b/config/common_base
> > @@ -726,6 +726,7 @@ CONFIG_RTE_LIBRTE_MEMPOOL_DEBUG=n  #
> > CONFIG_RTE_DRIVER_MEMPOOL_BUCKET=y
> >  CONFIG_RTE_DRIVER_MEMPOOL_BUCKET_SIZE_KB=64
> > +CONFIG_RTE_DRIVER_MEMPOOL_NB_STACK=y
> 
> NAK,  as this applies to x86_64 only, it will break arm/ppc and even 32bit i386
> configurations.
> 

Hi Gavin,

This patch resolves that in the make and meson build files, which ensure that the library is only built for x86-64 targets:

diff --git a/drivers/mempool/Makefile b/drivers/mempool/Makefile
index 28c2e8360..895cf8a34 100644
--- a/drivers/mempool/Makefile
+++ b/drivers/mempool/Makefile
@@ -10,6 +10,9 @@ endif
 ifeq ($(CONFIG_RTE_EAL_VFIO)$(CONFIG_RTE_LIBRTE_FSLMC_BUS),yy)
 DIRS-$(CONFIG_RTE_LIBRTE_DPAA2_MEMPOOL) += dpaa2
 endif
+ifeq ($(CONFIG_RTE_ARCH_X86_64),y)
+DIRS-$(CONFIG_RTE_DRIVER_MEMPOOL_NB_STACK) += nb_stack
+endif

diff --git a/drivers/mempool/nb_stack/meson.build b/drivers/mempool/nb_stack/meson.build
new file mode 100644
index 000000000..4a699511d
--- /dev/null
+++ b/drivers/mempool/nb_stack/meson.build
@@ -0,0 +1,8 @@
+# SPDX-License-Identifier: BSD-3-Clause
+# Copyright(c) 2019 Intel Corporation
+
+if arch_subdir != 'x86' or cc.sizeof('void *') == 4
+	build = false
+endif
+
+sources = files('rte_mempool_nb_stack.c')

(Note: this code was pulled from the v3 patch)

You can see successful 32-bit builds at the dpdk-test-report here: http://mails.dpdk.org/archives/test-report/2019-January/073636.html

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