From: "Ananyev, Konstantin" <konstantin.ananyev@intel.com>
To: Rahul Lakkireddy <rahul.lakkireddy@chelsio.com>,
Aaron Conole <aconole@redhat.com>
Cc: "dev@dpdk.org" <dev@dpdk.org>, Felix Marti <felix@chelsio.com>,
Nirranjan Kirubaharan <nirranjan@chelsio.com>,
Kumar A S <kumaras@chelsio.com>
Subject: Re: [dpdk-dev] [PATCH 1/6] cxgbe: Optimize forwarding performance for 40G
Date: Mon, 5 Oct 2015 11:46:40 +0000 [thread overview]
Message-ID: <2601191342CEEE43887BDE71AB97725836AA36CF@irsmsx105.ger.corp.intel.com> (raw)
In-Reply-To: <20151005100620.GA2487@scalar.blr.asicdesigners.com>
> -----Original Message-----
> From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Rahul Lakkireddy
> Sent: Monday, October 05, 2015 11:06 AM
> To: Aaron Conole
> Cc: dev@dpdk.org; Felix Marti; Kumar A S; Nirranjan Kirubaharan
> Subject: Re: [dpdk-dev] [PATCH 1/6] cxgbe: Optimize forwarding performance for 40G
>
> Hi Aaron,
>
> On Friday, October 10/02/15, 2015 at 14:48:28 -0700, Aaron Conole wrote:
> > Hi Rahul,
> >
> > Rahul Lakkireddy <rahul.lakkireddy@chelsio.com> writes:
> >
> > > Update sge initialization with respect to free-list manager configuration
> > > and ingress arbiter. Also update refill logic to refill mbufs only after
> > > a certain threshold for rx. Optimize tx packet prefetch and free.
> > <<snip>>
> > > for (i = 0; i < sd->coalesce.idx; i++) {
> > > - rte_pktmbuf_free(sd->coalesce.mbuf[i]);
> > > + struct rte_mbuf *tmp = sd->coalesce.mbuf[i];
> > > +
> > > + do {
> > > + struct rte_mbuf *next = tmp->next;
> > > +
> > > + rte_pktmbuf_free_seg(tmp);
> > > + tmp = next;
> > > + } while (tmp);
> > > sd->coalesce.mbuf[i] = NULL;
> > Pardon my ignorance here, but rte_pktmbuf_free does this work. I can't
> > actually see much difference between your rewrite of this block, and
> > the implementation of rte_pktmbuf_free() (apart from moving your branch
> > to the end of the function). Did your microbenchmarking really show this
> > as an improvement?
> >
> > Thanks for your time,
> > Aaron
>
> rte_pktmbuf_free calls rte_mbuf_sanity_check which does a lot of
> checks.
Only when RTE_LIBRTE_MBUF_DEBUG is enabled in your config.
By default it is switched off.
> This additional check seems redundant for single segment
> packets since rte_pktmbuf_free_seg also performs rte_mbuf_sanity_check.
>
> Several PMDs already prefer to use rte_pktmbuf_free_seg directly over
> rte_pktmbuf_free as it is faster.
Other PMDs use rte_pktmbuf_free_seg() as each TD has an associated
with it segment. So as HW is done with the TD, SW frees associated segment.
In your case I don't see any point in re-implementing rte_pktmbuf_free() manually,
and I don't think it would be any faster.
Konstantin
>
> The forwarding perf. improvement with only this particular block is
> around 1 Mpps for 64B packets when using l3fwd with 8 queues.
>
> Thanks,
> Rahul
next prev parent reply other threads:[~2015-10-05 11:46 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-10-02 11:16 [dpdk-dev] [PATCH 0/6] cxgbe: Optimize tx/rx for 40GbE and add Jumbo Frame support for CXGBE PMD Rahul Lakkireddy
2015-10-02 11:16 ` [dpdk-dev] [PATCH 1/6] cxgbe: Optimize forwarding performance for 40G Rahul Lakkireddy
2015-10-02 21:48 ` Aaron Conole
2015-10-05 10:06 ` Rahul Lakkireddy
2015-10-05 11:46 ` Ananyev, Konstantin [this message]
2015-10-05 12:42 ` Rahul Lakkireddy
2015-10-05 14:09 ` Ananyev, Konstantin
2015-10-05 15:07 ` Rahul Lakkireddy
2015-10-07 15:27 ` Rahul Lakkireddy
2015-10-02 11:16 ` [dpdk-dev] [PATCH 2/6] cxgbe: Update device info and perform sanity checks to enable jumbo frames Rahul Lakkireddy
2015-10-02 11:16 ` [dpdk-dev] [PATCH 3/6] cxgbe: Update tx path to transmit " Rahul Lakkireddy
2015-10-02 11:16 ` [dpdk-dev] [PATCH 4/6] cxgbe: Update rx path to receive " Rahul Lakkireddy
2015-10-02 11:16 ` [dpdk-dev] [PATCH 5/6] cxgbe: Allow apps to change mtu Rahul Lakkireddy
2015-10-02 11:16 ` [dpdk-dev] [PATCH 6/6] doc: Update cxgbe documentation and release notes Rahul Lakkireddy
2015-10-08 13:46 ` [dpdk-dev] [PATCH v2 0/6] cxgbe: Optimize tx/rx for 40GbE and add Jumbo Frame support for CXGBE PMD Rahul Lakkireddy
2015-10-08 13:46 ` [dpdk-dev] [PATCH v2 1/6] cxgbe: Optimize forwarding performance for 40G Rahul Lakkireddy
2015-10-08 13:46 ` [dpdk-dev] [PATCH v2 2/6] cxgbe: Update device info and perform sanity checks to enable jumbo frames Rahul Lakkireddy
2015-10-08 13:46 ` [dpdk-dev] [PATCH v2 3/6] cxgbe: Update tx path to transmit " Rahul Lakkireddy
2015-10-08 13:46 ` [dpdk-dev] [PATCH v2 4/6] cxgbe: Update rx path to receive " Rahul Lakkireddy
2015-10-08 13:46 ` [dpdk-dev] [PATCH v2 5/6] cxgbe: Allow apps to change mtu Rahul Lakkireddy
2015-10-08 13:46 ` [dpdk-dev] [PATCH v2 6/6] doc: Update cxgbe documentation and release notes Rahul Lakkireddy
2015-10-20 16:51 ` [dpdk-dev] [PATCH v2 0/6] cxgbe: Optimize tx/rx for 40GbE and add Jumbo Frame support for CXGBE PMD Thomas Monjalon
2015-10-21 6:14 ` Rahul Lakkireddy
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=2601191342CEEE43887BDE71AB97725836AA36CF@irsmsx105.ger.corp.intel.com \
--to=konstantin.ananyev@intel.com \
--cc=aconole@redhat.com \
--cc=dev@dpdk.org \
--cc=felix@chelsio.com \
--cc=kumaras@chelsio.com \
--cc=nirranjan@chelsio.com \
--cc=rahul.lakkireddy@chelsio.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).