From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jerin Jacob Subject: Re: [PATCH v1 01/14] ring: remove split cacheline build setting Date: Tue, 28 Feb 2017 23:24:25 +0530 Message-ID: <20170228175423.GA23591@localhost.localdomain> References: <20170223172407.27664-1-bruce.richardson@intel.com> <20170223172407.27664-2-bruce.richardson@intel.com> <20170228113511.GA28584@localhost.localdomain> <20170228115703.GA4656@bricha3-MOBL3.ger.corp.intel.com> <20170228120833.GA30817@localhost.localdomain> <20170228135226.GA9784@bricha3-MOBL3.ger.corp.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: olivier.matz@6wind.com, dev@dpdk.org To: Bruce Richardson Return-path: Received: from NAM03-CO1-obe.outbound.protection.outlook.com (mail-co1nam03on0085.outbound.protection.outlook.com [104.47.40.85]) by dpdk.org (Postfix) with ESMTP id 58BF72B86 for ; Tue, 28 Feb 2017 18:54:51 +0100 (CET) Content-Disposition: inline In-Reply-To: <20170228135226.GA9784@bricha3-MOBL3.ger.corp.intel.com> List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" On Tue, Feb 28, 2017 at 01:52:26PM +0000, Bruce Richardson wrote: > On Tue, Feb 28, 2017 at 05:38:34PM +0530, Jerin Jacob wrote: > > On Tue, Feb 28, 2017 at 11:57:03AM +0000, Bruce Richardson wrote: > > > On Tue, Feb 28, 2017 at 05:05:13PM +0530, Jerin Jacob wrote: > > > > On Thu, Feb 23, 2017 at 05:23:54PM +0000, Bruce Richardson wrote: > > > > > Users compiling DPDK should not need to know or care about the arrangement > > > > > of cachelines in the rte_ring structure. Therefore just remove the build > > > > > option and set the structures to be always split. For improved > > > > > performance use 128B rather than 64B alignment since it stops the producer > > > > > and consumer data being on adjacent cachelines. > > > > > > > > > > Signed-off-by: Bruce Richardson > > > > > --- > > > > > config/common_base | 1 - > > > > > doc/guides/rel_notes/release_17_05.rst | 6 ++++++ > > > > > lib/librte_ring/rte_ring.c | 2 -- > > > > > lib/librte_ring/rte_ring.h | 8 ++------ > > > > > 4 files changed, 8 insertions(+), 9 deletions(-) > > > > > > > > > > diff --git a/config/common_base b/config/common_base > > > > > index aeee13e..099ffda 100644 > > > > > --- a/config/common_base > > > > > +++ b/config/common_base > > > > > @@ -448,7 +448,6 @@ CONFIG_RTE_LIBRTE_PMD_NULL_CRYPTO=y > > > > > # > > > > > CONFIG_RTE_LIBRTE_RING=y > > > > > CONFIG_RTE_LIBRTE_RING_DEBUG=n > > > > > -CONFIG_RTE_RING_SPLIT_PROD_CONS=n > > > > > CONFIG_RTE_RING_PAUSE_REP_COUNT=0 > > > > > > > > > > # > > > > > diff --git a/doc/guides/rel_notes/release_17_05.rst b/doc/guides/rel_notes/release_17_05.rst > > > > > index e25ea9f..ea45e0c 100644 > > > > > --- a/doc/guides/rel_notes/release_17_05.rst > > > > > +++ b/doc/guides/rel_notes/release_17_05.rst > > > > > @@ -110,6 +110,12 @@ API Changes > > > > > Also, make sure to start the actual text at the margin. > > > > > ========================================================= > > > > > > > > > > +* **Reworked rte_ring library** > > > > > + > > > > > + The rte_ring library has been reworked and updated. The following changes > > > > > + have been made to it: > > > > > + > > > > > + * removed the build-time setting ``CONFIG_RTE_RING_SPLIT_PROD_CONS`` > > > > > > > > > > ABI Changes > > > > > ----------- > > > > > diff --git a/lib/librte_ring/rte_ring.c b/lib/librte_ring/rte_ring.c > > > > > index ca0a108..4bc6da1 100644 > > > > > --- a/lib/librte_ring/rte_ring.c > > > > > +++ b/lib/librte_ring/rte_ring.c > > > > > @@ -127,10 +127,8 @@ rte_ring_init(struct rte_ring *r, const char *name, unsigned count, > > > > > /* compilation-time checks */ > > > > > RTE_BUILD_BUG_ON((sizeof(struct rte_ring) & > > > > > RTE_CACHE_LINE_MASK) != 0); > > > > > -#ifdef RTE_RING_SPLIT_PROD_CONS > > > > > RTE_BUILD_BUG_ON((offsetof(struct rte_ring, cons) & > > > > > RTE_CACHE_LINE_MASK) != 0); > > > > > -#endif > > > > > RTE_BUILD_BUG_ON((offsetof(struct rte_ring, prod) & > > > > > RTE_CACHE_LINE_MASK) != 0); > > > > > #ifdef RTE_LIBRTE_RING_DEBUG > > > > > diff --git a/lib/librte_ring/rte_ring.h b/lib/librte_ring/rte_ring.h > > > > > index 72ccca5..04fe667 100644 > > > > > --- a/lib/librte_ring/rte_ring.h > > > > > +++ b/lib/librte_ring/rte_ring.h > > > > > @@ -168,7 +168,7 @@ struct rte_ring { > > > > > uint32_t mask; /**< Mask (size-1) of ring. */ > > > > > volatile uint32_t head; /**< Producer head. */ > > > > > volatile uint32_t tail; /**< Producer tail. */ > > > > > - } prod __rte_cache_aligned; > > > > > + } prod __rte_aligned(RTE_CACHE_LINE_SIZE * 2); > > > > > > > > I think we need to use RTE_CACHE_LINE_MIN_SIZE instead of > > > > RTE_CACHE_LINE_SIZE for alignment here. PPC and ThunderX1 targets are cache line > > > > size of 128B > > > > > > > Sure. > > > > > > However, can you perhaps try a performance test and check to see if > > > there is a performance difference between the two values before I change > > > it? In my tests I see improved performance by having an extra blank > > > cache-line between the producer and consumer data. > > > > Sure. Which test are you running to measure the performance difference? > > Is it app/test/test_ring_perf.c? > > > > > > Yep, just the basic ring perf test. I look mostly at the core-to-core > numbers, since hyperthread-to-hyperthread or NUMA socket to NUMA socket > would be far less common use cases IMHO. Performance test result shows regression with RTE_CACHE_LINE_MIN_SIZE scheme in some use case and some use case has higher performance(Testing using two physical cores) # base code RTE>>ring_perf_autotest ### Testing single element and burst enq/deq ### SP/SC single enq/dequeue: 84 MP/MC single enq/dequeue: 301 SP/SC burst enq/dequeue (size: 8): 20 MP/MC burst enq/dequeue (size: 8): 46 SP/SC burst enq/dequeue (size: 32): 12 MP/MC burst enq/dequeue (size: 32): 18 ### Testing empty dequeue ### SC empty dequeue: 7.11 MC empty dequeue: 12.15 ### Testing using a single lcore ### SP/SC bulk enq/dequeue (size: 8): 19.08 MP/MC bulk enq/dequeue (size: 8): 46.28 SP/SC bulk enq/dequeue (size: 32): 11.89 MP/MC bulk enq/dequeue (size: 32): 18.84 ### Testing using two physical cores ### SP/SC bulk enq/dequeue (size: 8): 37.42 MP/MC bulk enq/dequeue (size: 8): 73.32 SP/SC bulk enq/dequeue (size: 32): 18.69 MP/MC bulk enq/dequeue (size: 32): 24.59 Test OK # with ring rework patch RTE>>ring_perf_autotest ### Testing single element and burst enq/deq ### SP/SC single enq/dequeue: 84 MP/MC single enq/dequeue: 301 SP/SC burst enq/dequeue (size: 8): 19 MP/MC burst enq/dequeue (size: 8): 45 SP/SC burst enq/dequeue (size: 32): 11 MP/MC burst enq/dequeue (size: 32): 18 ### Testing empty dequeue ### SC empty dequeue: 7.10 MC empty dequeue: 12.15 ### Testing using a single lcore ### SP/SC bulk enq/dequeue (size: 8): 18.59 MP/MC bulk enq/dequeue (size: 8): 45.49 SP/SC bulk enq/dequeue (size: 32): 11.67 MP/MC bulk enq/dequeue (size: 32): 18.65 ### Testing using two physical cores ### SP/SC bulk enq/dequeue (size: 8): 37.41 MP/MC bulk enq/dequeue (size: 8): 72.98 SP/SC bulk enq/dequeue (size: 32): 18.69 MP/MC bulk enq/dequeue (size: 32): 24.59 Test OK RTE>> # with ring rework patch + cache-line size change to one on 128BCL target RTE>>ring_perf_autotest ### Testing single element and burst enq/deq ### SP/SC single enq/dequeue: 90 MP/MC single enq/dequeue: 317 SP/SC burst enq/dequeue (size: 8): 20 MP/MC burst enq/dequeue (size: 8): 48 SP/SC burst enq/dequeue (size: 32): 11 MP/MC burst enq/dequeue (size: 32): 18 ### Testing empty dequeue ### SC empty dequeue: 8.10 MC empty dequeue: 11.15 ### Testing using a single lcore ### SP/SC bulk enq/dequeue (size: 8): 20.24 MP/MC bulk enq/dequeue (size: 8): 48.43 SP/SC bulk enq/dequeue (size: 32): 11.01 MP/MC bulk enq/dequeue (size: 32): 18.43 ### Testing using two physical cores ### SP/SC bulk enq/dequeue (size: 8): 25.92 MP/MC bulk enq/dequeue (size: 8): 69.76 SP/SC bulk enq/dequeue (size: 32): 14.27 MP/MC bulk enq/dequeue (size: 32): 22.94 Test OK RTE>>