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

Eads, Gage gage.eads at intel.com
Thu Jan 17 16:16:28 CET 2019



> -----Original Message-----
> From: Richardson, Bruce
> Sent: Thursday, January 17, 2019 8:21 AM
> To: Eads, Gage <gage.eads at intel.com>
> Cc: Gavin Hu (Arm Technology China) <Gavin.Hu at arm.com>; dev at dpdk.org;
> olivier.matz at 6wind.com; arybchenko at solarflare.com; Ananyev, Konstantin
> <konstantin.ananyev at intel.com>; Honnappa Nagarahalli
> <Honnappa.Nagarahalli at arm.com>; Ruifeng Wang (Arm Technology China)
> <Ruifeng.Wang at arm.com>; Phil Yang (Arm Technology China)
> <Phil.Yang at arm.com>
> Subject: Re: [dpdk-dev] [PATCH v2 2/2] mempool/nb_stack: add non-blocking
> stack mempool
> 
> On Thu, Jan 17, 2019 at 02:11:22PM +0000, Eads, Gage wrote:
> >
> >
> > > -----Original Message-----
> > > From: Gavin Hu (Arm Technology China) [mailto:Gavin.Hu at arm.com]
> > > Sent: Thursday, January 17, 2019 2:06 AM
> > > To: Eads, Gage <gage.eads at intel.com>; dev at dpdk.org
> > > Cc: olivier.matz at 6wind.com; arybchenko at solarflare.com; Richardson,
> > > Bruce <bruce.richardson at intel.com>; Ananyev, Konstantin
> > > <konstantin.ananyev at intel.com>; Honnappa Nagarahalli
> > > <Honnappa.Nagarahalli at arm.com>; Ruifeng Wang (Arm Technology China)
> > > <Ruifeng.Wang at arm.com>; Phil Yang (Arm Technology China)
> > > <Phil.Yang at arm.com>
> > > Subject: RE: [dpdk-dev] [PATCH v2 2/2] mempool/nb_stack: add
> > > non-blocking stack mempool
> > >
> > >
> > > > -----Original Message-----
> > > > From: dev <dev-bounces at dpdk.org> On Behalf Of Gage Eads
> > > > Sent: Wednesday, January 16, 2019 6:33 AM
> > > > To: dev at dpdk.org
> > > > Cc: olivier.matz at 6wind.com; arybchenko at solarflare.com;
> > > > bruce.richardson at intel.com; konstantin.ananyev at 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 at 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 at oktetlabs.ru>
> > > >  M: Andrew Rybchenko <arybchenko at solarflare.com>
> > > >  F: drivers/mempool/bucket/
> > > >
> > > > +Non-blocking stack memory pool
> > > > +M: Gage Eads <gage.eads at 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
> > +
> 
> Minor suggestion:
> Can be simplified to "build = dpdk_conf.has('RTE_ARCH_X86_64')", I believe.
> 
> /Bruce

Sure, I'll switch to that check in v4.

Thanks,
Gage


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