From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga14.intel.com (mga14.intel.com [192.55.52.115]) by dpdk.org (Postfix) with ESMTP id 8D396590B for ; Fri, 7 Nov 2014 15:55:58 +0100 (CET) Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by fmsmga103.fm.intel.com with ESMTP; 07 Nov 2014 06:58:36 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.07,332,1413270000"; d="scan'208";a="618882458" Received: from bricha3-mobl3.ger.corp.intel.com ([10.243.20.32]) by fmsmga001.fm.intel.com with SMTP; 07 Nov 2014 07:04:30 -0800 Received: by (sSMTP sendmail emulation); Fri, 07 Nov 2014 15:04:29 +0025 Date: Fri, 7 Nov 2014 15:04:29 +0000 From: Bruce Richardson To: jigsaw Message-ID: <20141107150429.GD12092@bricha3-MOBL3> References: <545b6b74.a96db40a.26af.ffffe7fb@mx.google.com> <20141106135951.GB7252@bricha3-MOBL3> <20141107094521.GB4628@bricha3-MOBL3> <20141107135303.GB12092@bricha3-MOBL3> <20141107144410.GC12092@bricha3-MOBL3> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Organization: Intel Shannon Ltd. User-Agent: Mutt/1.5.23 (2014-03-12) Cc: "dev@dpdk.org" Subject: Re: [dpdk-dev] =?utf-8?b?562U5aSNOiAgW1BBVENIXSBBZGQgdXNlciBkZWZpbmVk?= =?utf-8?q?_tag_calculation_callback_tolibrte=5Fdistributor=2E?= X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: patches and discussions about DPDK List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 07 Nov 2014 14:55:59 -0000 On Fri, Nov 07, 2014 at 04:52:46PM +0200, jigsaw wrote: > Yeah that's better. As below, right? Yep. > > @@ -290,6 +294,7 @@ rte_distributor_process(struct rte_distributor *d, > match |= (!(d->in_flight_tags[i] ^ new_tag) > << i); > > + match &= d->in_flight_bitmask; > if (match) { > next_mb = NULL; > unsigned worker = __builtin_ctz(match); > > > On Fri, Nov 7, 2014 at 4:44 PM, Bruce Richardson > wrote: > > > On Fri, Nov 07, 2014 at 04:31:18PM +0200, jigsaw wrote: > > > Hi Bruce, > > > > > > Pls have a quick look at the diff to see if this is exactly what you mean > > > about the bitmask. > > > I just wrote it without even compiling, just to express the idea. So it > > may > > > leave some places unpatched. > > > If this is agreed, I will make a decent test to verify it before sending > > > the patch for RFC. > > > > > > diff --git a/lib/librte_distributor/rte_distributor.c > > > b/lib/librte_distributor/rte_di > > > index 585ff88..d606bcf 100644 > > > --- a/lib/librte_distributor/rte_distributor.c > > > +++ b/lib/librte_distributor/rte_distributor.c > > > @@ -92,6 +92,8 @@ struct rte_distributor { > > > unsigned num_workers; /**< Number of workers > > > polling */ > > > > > > uint32_t in_flight_tags[RTE_MAX_LCORE]; > > > + uint32_t in_flight_bitmask; > > > + > > > struct rte_distributor_backlog backlog[RTE_MAX_LCORE]; > > > > > > union rte_distributor_buffer bufs[RTE_MAX_LCORE]; > > > @@ -188,6 +190,7 @@ static inline void > > > handle_worker_shutdown(struct rte_distributor *d, unsigned wkr) > > > { > > > d->in_flight_tags[wkr] = 0; > > > + d->in_flight_mask &= ~(1 << wkr); > > > d->bufs[wkr].bufptr64 = 0; > > > if (unlikely(d->backlog[wkr].count != 0)) { > > > /* On return of a packet, we need to move the > > > @@ -241,6 +244,7 @@ process_returns(struct rte_distributor *d) > > > else { > > > d->bufs[wkr].bufptr64 = > > RTE_DISTRIB_GET_BUF; > > > d->in_flight_tags[wkr] = 0; > > > + d->in_flight_mask &= ~(1 << wkr); > > > } > > > oldbuf = data >> RTE_DISTRIB_FLAG_BITS; > > > } else if (data & RTE_DISTRIB_RETURN_BUF) { > > > @@ -282,12 +286,13 @@ rte_distributor_process(struct rte_distributor *d, > > > next_mb = mbufs[next_idx++]; > > > next_value = (((int64_t)(uintptr_t)next_mb) > > > << RTE_DISTRIB_FLAG_BITS); > > > - new_tag = (next_mb->hash.rss | 1); > > > + new_tag = next_mb->hash.rss; > > > > > > uint32_t match = 0; > > > unsigned i; > > > for (i = 0; i < d->num_workers; i++) > > > - match |= (!(d->in_flight_tags[i] ^ > > new_tag) > > > + match |= (((!(d->in_flight_tags[i] ^ > > > new_tag)) & > > > + (d->in_flight_bitmask >> > > i)) > > > > I would not do the bitmask comparison here, as that's extra instruction in > > the > > loop. Instead, because its a bitmask, build up the match variable as it was > > before, and then just do a single and operation afterwards, outside the > > loop > > body. > > > > /Bruce > > > > > << i); > > > > > > if (match) { > > > @@ -309,6 +314,7 @@ rte_distributor_process(struct rte_distributor *d, > > > else { > > > d->bufs[wkr].bufptr64 = next_value; > > > d->in_flight_tags[wkr] = new_tag; > > > + d->in_flight_bitmask |= 1 << wkr; > > > next_mb = NULL; > > > } > > > oldbuf = data >> RTE_DISTRIB_FLAG_BITS; > > > > > > > > > > >