From: "Ananyev, Konstantin" <konstantin.ananyev@intel.com>
To: "Zhao, Bing" <ilovethull@163.com>, Jia He <hejianet@gmail.com>,
"Jerin Jacob" <jerin.jacob@caviumnetworks.com>
Cc: Olivier MATZ <olivier.matz@6wind.com>,
"dev@dpdk.org" <dev@dpdk.org>,
"jia.he@hxt-semitech.com" <jia.he@hxt-semitech.com>,
"jie2.liu@hxt-semitech.com" <jie2.liu@hxt-semitech.com>,
"bing.zhao@hxt-semitech.com" <bing.zhao@hxt-semitech.com>
Subject: Re: [dpdk-dev] [PATCH] ring: guarantee ordering of cons/prod loading when doing enqueue/dequeue
Date: Thu, 19 Oct 2017 14:15:00 +0000 [thread overview]
Message-ID: <2601191342CEEE43887BDE71AB9772585FAAB404@IRSMSX103.ger.corp.intel.com> (raw)
In-Reply-To: <8806e2bd-c57b-03ff-a315-0a311690f1d9@163.com>
>
> Hi,
>
> On 2017/10/19 18:02, Ananyev, Konstantin wrote:
> >
> > Hi Jia,
> >
> >>
> >> Hi
> >>
> >>
> >> On 10/13/2017 9:02 AM, Jia He Wrote:
> >>> Hi Jerin
> >>>
> >>>
> >>> On 10/13/2017 1:23 AM, Jerin Jacob Wrote:
> >>>> -----Original Message-----
> >>>>> Date: Thu, 12 Oct 2017 17:05:50 +0000
> >>>>>
> >> [...]
> >>>> On the same lines,
> >>>>
> >>>> Jia He, jie2.liu, bing.zhao,
> >>>>
> >>>> Is this patch based on code review or do you saw this issue on any of
> >>>> the
> >>>> arm/ppc target? arm64 will have performance impact with this change.
> >> sorry, miss one important information
> >> Our platform is an aarch64 server with 46 cpus.
> >> If we reduced the involved cpu numbers, the bug occurred less frequently.
> >>
> >> Yes, mb barrier impact the performance, but correctness is more
> >> important, isn't it ;-)
> >> Maybe we can find any other lightweight barrier here?
> >>
> >> Cheers,
> >> Jia
> >>> Based on mbuf_autotest, the rte_panic will be invoked in seconds.
> >>>
> >>> PANIC in test_refcnt_iter():
> >>> (lcore=0, iter=0): after 10s only 61 of 64 mbufs left free
> >>> 1: [./test(rte_dump_stack+0x38) [0x58d868]]
> >>> Aborted (core dumped)
> >>>
> >
> > So is it only reproducible with mbuf refcnt test?
> > Could it be reproduced with some 'pure' ring test
> > (no mempools/mbufs refcnt, etc.)?
> > The reason I am asking - in that test we also have mbuf refcnt updates
> > (that's what for that test was created) and we are doing some optimizations here too
> > to avoid excessive atomic updates.
> > BTW, if the problem is not reproducible without mbuf refcnt,
> > can I suggest to extend the test with:
> > - add a check that enqueue() operation was successful
> > - walk through the pool and check/printf refcnt of each mbuf.
> > Hopefully that would give us some extra information what is going wrong here.
> > Konstantin
> >
> >
> Currently, the issue is only found in this case here on the ARM
> platform, not sure how it is going with the X86_64 platform
I understand that it is only reproducible on arm so far.
What I am asking - with dpdk is there any other way to reproduce it (on arm)
except then running mbuf_autotest?
Something really simple that not using mbuf/mempool etc?
Just do dequeue/enqueue from multiple threads and check data integrity at the end?
If not - what makes you think that the problem is precisely in rte_ring code?
Why not in rte_mbuf let say?
>. In another
> mail of this thread, we've made a simple test based on this and captured
> some information and I pasted there.(I pasted the patch there :-))
Are you talking about that one:
http://dpdk.org/dev/patchwork/patch/30405/
?
It still uses test/test/test_mbuf.c...,
but anyway I don't really understand how mbuf_autotest supposed
to work with these changes:
@@ -730,7 +739,7 @@ test_refcnt_iter(unsigned int lcore, unsigned int iter,
rte_ring_enqueue(refcnt_mbuf_ring, m);
}
}
- rte_pktmbuf_free(m);
+ // rte_pktmbuf_free(m);
}
@@ -741,6 +750,12 @@ test_refcnt_iter(unsigned int lcore, unsigned int iter,
while (!rte_ring_empty(refcnt_mbuf_ring))
;
+ if (NULL != m) {
+ if (1 != rte_mbuf_refcnt_read(m))
+ printf("m ref is %u\n", rte_mbuf_refcnt_read(m));
+ rte_pktmbuf_free(m);
+ }
+
/* check that all mbufs are back into mempool by now */
for (wn = 0; wn != REFCNT_MAX_TIMEOUT; wn++) {
if ((i = rte_mempool_avail_count(refcnt_pool)) == n) {
That means all your mbufs (except the last one) will still be allocated.
So the test would fail - as it should, I think.
> And
> it seems that Juhamatti & Jacod found some reverting action several
> months ago.
Didn't get that one either.
Konstantin
next prev parent reply other threads:[~2017-10-19 14:15 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-10-10 9:56 Jia He
2017-10-12 15:53 ` Olivier MATZ
2017-10-12 16:15 ` Stephen Hemminger
2017-10-12 17:05 ` Ananyev, Konstantin
2017-10-12 17:23 ` Jerin Jacob
2017-10-13 1:02 ` Jia He
2017-10-13 1:15 ` Jia He
2017-10-13 1:16 ` Jia He
2017-10-13 1:49 ` Jerin Jacob
2017-10-13 3:23 ` Jia He
2017-10-13 5:57 ` Zhao, Bing
2017-10-13 7:33 ` Jianbo Liu
2017-10-13 8:20 ` Jia He
2017-10-19 10:02 ` Ananyev, Konstantin
2017-10-19 11:18 ` Zhao, Bing
2017-10-19 14:15 ` Ananyev, Konstantin [this message]
2017-10-19 20:02 ` Ananyev, Konstantin
2017-10-20 1:57 ` Jia He
2017-10-20 5:43 ` Jerin Jacob
2017-10-23 8:49 ` Jia He
2017-10-23 9:05 ` Kuusisaari, Juhamatti
2017-10-23 9:10 ` Bruce Richardson
2017-10-23 10:06 ` Jerin Jacob
2017-10-24 2:04 ` Jia He
2017-10-25 13:26 ` Jerin Jacob
2017-10-26 2:27 ` Jia He
2017-10-31 2:55 ` Jia He
2017-10-31 11:14 ` Jerin Jacob
2017-11-01 2:53 ` Jia He
2017-11-01 19:04 ` Jerin Jacob
2017-11-02 1:09 ` Jia He
2017-11-02 8:57 ` Jia He
2017-11-03 2:55 ` Jia He
2017-11-03 12:47 ` Jerin Jacob
2017-11-01 4:48 ` Jia He
2017-11-01 19:10 ` Jerin Jacob
2017-10-20 7:03 ` Ananyev, Konstantin
2017-10-13 0:24 ` Liu, Jie2
2017-10-13 2:12 ` Zhao, Bing
2017-10-13 2:34 ` Jerin Jacob
2017-10-16 10:51 ` Kuusisaari, Juhamatti
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