From: Alejandro Lucero <alejandro.lucero@netronome.com>
To: xueqin.lin@intel.com
Cc: lei.a.yao@intel.com, Thomas Monjalon <thomas@monjalon.net>,
dev <dev@dpdk.org>, "Xu, Qian Q" <qian.q.xu@intel.com>,
"Burakov, Anatoly" <anatoly.burakov@intel.com>,
Ferruh Yigit <ferruh.yigit@intel.com>,
Qi Zhang <qi.z.zhang@intel.com>
Subject: Re: [dpdk-dev] [PATCH v3 0/6] use IOVAs check based on DMA mask
Date: Tue, 30 Oct 2018 09:41:05 +0000 [thread overview]
Message-ID: <CAD+H991JcFLViqCLHC4Nda5vUVSQRwi2EyJ0jCbHqD5=s+G8Yg@mail.gmail.com> (raw)
In-Reply-To: <0D300480287911409D9FF92C1FA2A3355B442C48@SHSMSX104.ccr.corp.intel.com>
On Tue, Oct 30, 2018 at 3:20 AM Lin, Xueqin <xueqin.lin@intel.com> wrote:
> Hi Lucero&Thomas,
>
>
>
> Find the patch can’t fix multi-process cases.
>
Hi,
I think it is not specifically about multiprocess but about hotplug with
multiprocess because I can execute the symmetric_mp successfully with a
secondary process.
Working on this as a priority.
Thanks.
> Steps:
>
> 1. Setup primary process successfully
>
> ./hotplug_mp --proc-type=auto
>
>
>
> 2. Fail to setup secondary process
>
> ./hotplug_mp --proc-type=auto
>
> EAL: Detected 88 lcore(s)
>
> EAL: Detected 2 NUMA nodes
>
> EAL: Auto-detected process type: SECONDARY
>
> EAL: Multi-process socket /var/run/dpdk/rte/mp_socket_147212_2bfe08ee88d23
>
> Segmentation fault (core dumped)
>
>
>
> More information as below:
>
> Thread 1 "hotplug_mp" received signal SIGSEGV, Segmentation fault.
>
> 0x0000000000597cfb in find_next (arr=0x7ffff7ff20a4, start=0, used=true)
>
> at /root/dpdk/lib/librte_eal/common/eal_common_fbarray.c:264
>
> 264 for (idx = first; idx < msk->n_masks; idx++) {
>
> #0 0x0000000000597cfb in find_next (arr=0x7ffff7ff20a4, start=0,
> used=true)
>
> at /root/dpdk/lib/librte_eal/common/eal_common_fbarray.c:264
>
> #1 0x0000000000598573 in fbarray_find (arr=0x7ffff7ff20a4, start=0,
> next=true,
>
> used=true) at
> /root/dpdk/lib/librte_eal/common/eal_common_fbarray.c:1001
>
> #2 0x000000000059929b in rte_fbarray_find_next_used (arr=0x7ffff7ff20a4,
> start=0)
>
> at /root/dpdk/lib/librte_eal/common/eal_common_fbarray.c:1018
>
> #3 0x000000000058c877 in rte_memseg_walk_thread_unsafe (func=0x58c401
> <check_iova>,
>
> arg=0x7fffffffcc38) at
> /root/dpdk/lib/librte_eal/common/eal_common_memory.c:589
>
> #4 0x000000000058ce08 in rte_eal_check_dma_mask (maskbits=48 '0')
>
> at /root/dpdk/lib/librte_eal/common/eal_common_memory.c:465
>
> #5 0x00000000005b96c4 in pci_one_device_iommu_support_va (dev=0x11b3d90)
>
> at /root/dpdk/drivers/bus/pci/linux/pci.c:593
>
> #6 0x00000000005b9738 in pci_devices_iommu_support_va ()
>
> at /root/dpdk/drivers/bus/pci/linux/pci.c:626
>
> #7 0x00000000005b97a7 in rte_pci_get_iommu_class ()
>
> at /root/dpdk/drivers/bus/pci/linux/pci.c:650
>
> #8 0x000000000058f1ce in rte_bus_get_iommu_class ()
>
> at /root/dpdk/lib/librte_eal/common/eal_common_bus.c:237
>
> #9 0x0000000000577c7a in rte_eal_init (argc=2, argv=0x7fffffffdf98)
>
> at /root/dpdk/lib/librte_eal/linuxapp/eal/eal.c:919
>
> #10 0x000000000045dd56 in main (argc=2, argv=0x7fffffffdf98)
>
> at /root/dpdk/examples/multi_process/hotplug_mp/main.c:28
>
>
>
>
>
> Best regards,
>
> Xueqin
>
>
>
> *From:* Alejandro Lucero [mailto:alejandro.lucero@netronome.com]
> *Sent:* Monday, October 29, 2018 9:41 PM
> *To:* Yao, Lei A <lei.a.yao@intel.com>
> *Cc:* Thomas Monjalon <thomas@monjalon.net>; dev <dev@dpdk.org>; Xu, Qian
> Q <qian.q.xu@intel.com>; Lin, Xueqin <xueqin.lin@intel.com>; Burakov,
> Anatoly <anatoly.burakov@intel.com>; Yigit, Ferruh <ferruh.yigit@intel.com
> >
> *Subject:* Re: [dpdk-dev] [PATCH v3 0/6] use IOVAs check based on DMA mask
>
>
>
>
>
> On Mon, Oct 29, 2018 at 1:18 PM Yao, Lei A <lei.a.yao@intel.com> wrote:
>
>
>
>
>
> *From:* Alejandro Lucero [mailto:alejandro.lucero@netronome.com]
> *Sent:* Monday, October 29, 2018 8:56 PM
> *To:* Thomas Monjalon <thomas@monjalon.net>
> *Cc:* Yao, Lei A <lei.a.yao@intel.com>; dev <dev@dpdk.org>; Xu, Qian Q <
> qian.q.xu@intel.com>; Lin, Xueqin <xueqin.lin@intel.com>; Burakov,
> Anatoly <anatoly.burakov@intel.com>; Yigit, Ferruh <ferruh.yigit@intel.com
> >
> *Subject:* Re: [dpdk-dev] [PATCH v3 0/6] use IOVAs check based on DMA mask
>
>
>
>
>
> On Mon, Oct 29, 2018 at 11:46 AM Thomas Monjalon <thomas@monjalon.net>
> wrote:
>
> 29/10/2018 12:39, Alejandro Lucero:
> > I got a patch that solves a bug when calling rte_eal_dma_mask using the
> > mask instead of the maskbits. However, this does not solves the
> deadlock.
>
> The deadlock is a bigger concern I think.
>
>
>
> I think once the call to rte_eal_check_dma_mask uses the maskbits instead
> of the mask, calling rte_memseg_walk_thread_unsafe avoids the deadlock.
>
>
>
> Yao, can you try with the attached patch?
>
>
>
> Hi, Lucero
>
>
>
> This patch can fix the issue at my side. Thanks a lot
>
> for you quick action.
>
>
>
>
>
> Great!
>
>
>
> I will send an official patch with the changes.
>
>
>
> I have to say that I tested the patchset, but I think it was where
> legacy_mem was still there and therefore dynamic memory allocation code not
> used during memory initialization.
>
>
>
> There is something that concerns me though. Using
> rte_memseg_walk_thread_unsafe could be a problem under some situations
> although those situations being unlikely.
>
>
>
> Usually, calling rte_eal_check_dma_mask happens during initialization.
> Then it is safe to use the unsafe function for walking memsegs, but with
> device hotplug and dynamic memory allocation, there exists a potential race
> condition when the primary process is allocating more memory and
> concurrently a device is hotplugged and a secondary process does the device
> initialization. By now, this is just a problem with the NFP, and the
> potential race condition window really unlikely, but I will work on this
> asap.
>
>
>
> BRs
>
> Lei
>
>
>
> > Interestingly, the problem looks like a compiler one. Calling
> > rte_memseg_walk does not return when calling inside rt_eal_dma_mask,
> but if
> > you modify the call like this:
> >
> > - if (rte_memseg_walk(check_iova, &mask))
> > + if (!rte_memseg_walk(check_iova, &mask))
> >
> > it works, although the value returned to the invoker changes, of course.
> > But the point here is it should be the same behaviour when calling
> > rte_memseg_walk than before and it is not.
>
> Anyway, the coding style requires to save the return value in a variable,
> instead of nesting the call in an "if" condition.
> And the "if" check should be explicitly != 0 because it is not a real
> boolean.
>
> PS: please do not top post and avoid HTML emails, thanks
>
>
next prev parent reply other threads:[~2018-10-30 9:41 UTC|newest]
Thread overview: 49+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-10-05 12:45 Alejandro Lucero
2018-10-05 12:45 ` [dpdk-dev] [PATCH v3 1/6] mem: add function for checking memsegs IOVAs addresses Alejandro Lucero
2018-10-10 8:56 ` Tu, Lijuan
2018-10-11 9:26 ` Alejandro Lucero
2018-10-28 21:03 ` Thomas Monjalon
2018-10-05 12:45 ` [dpdk-dev] [PATCH v3 2/6] mem: use address hint for mapping hugepages Alejandro Lucero
2018-10-29 16:08 ` Dariusz Stojaczyk
2018-10-29 16:40 ` Alejandro Lucero
2018-10-05 12:45 ` [dpdk-dev] [PATCH v3 3/6] bus/pci: check iommu addressing limitation just once Alejandro Lucero
2018-10-05 12:45 ` [dpdk-dev] [PATCH v3 4/6] bus/pci: use IOVAs dmak mask check when setting IOVA mode Alejandro Lucero
2018-10-05 12:45 ` [dpdk-dev] [PATCH v3 5/6] net/nfp: check hugepages IOVAs based on DMA mask Alejandro Lucero
2018-10-05 12:45 ` [dpdk-dev] [PATCH v3 6/6] net/nfp: support IOVA VA mode Alejandro Lucero
2018-10-28 21:04 ` [dpdk-dev] [PATCH v3 0/6] use IOVAs check based on DMA mask Thomas Monjalon
2018-10-29 8:23 ` Yao, Lei A
2018-10-29 8:42 ` Thomas Monjalon
2018-10-29 9:07 ` Thomas Monjalon
2018-10-29 9:25 ` Alejandro Lucero
2018-10-29 9:44 ` Yao, Lei A
2018-10-29 9:36 ` Yao, Lei A
2018-10-29 9:48 ` Thomas Monjalon
2018-10-29 10:11 ` Alejandro Lucero
2018-10-29 10:15 ` Alejandro Lucero
2018-10-29 11:39 ` Alejandro Lucero
2018-10-29 11:46 ` Thomas Monjalon
2018-10-29 12:55 ` Alejandro Lucero
2018-10-29 13:18 ` Yao, Lei A
2018-10-29 13:40 ` Alejandro Lucero
2018-10-29 14:18 ` Thomas Monjalon
2018-10-29 14:35 ` Alejandro Lucero
2018-10-29 18:54 ` Yongseok Koh
2018-10-29 19:37 ` Alejandro Lucero
2018-10-30 10:10 ` Burakov, Anatoly
2018-10-30 10:11 ` Burakov, Anatoly
2018-10-30 10:19 ` Alejandro Lucero
2018-10-30 3:20 ` Lin, Xueqin
2018-10-30 9:41 ` Alejandro Lucero [this message]
2018-10-30 10:33 ` Lin, Xueqin
2018-10-30 10:38 ` Alejandro Lucero
2018-10-30 12:21 ` Lin, Xueqin
2018-10-30 12:37 ` Alejandro Lucero
2018-10-30 14:04 ` Alejandro Lucero
2018-10-30 14:14 ` Burakov, Anatoly
2018-10-30 14:45 ` Alejandro Lucero
2018-10-30 14:45 ` Lin, Xueqin
2018-10-30 14:57 ` Alejandro Lucero
2018-10-30 15:09 ` Lin, Xueqin
2018-10-30 10:18 ` Burakov, Anatoly
2018-10-30 10:23 ` Alejandro Lucero
-- strict thread matches above, loose matches on Subject: below --
2018-07-04 12:53 Alejandro Lucero
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