Re: [dpdk-dev] [PATCH v3 0/6] use IOVAs check based on DMA mask

[Alejandro Lucero <alejandro.lucero@netronome.com>]

I know what is going on.

In patchset version 3 I forgot to remove an old code. Anatoly spotted that
and I was going to send another version for fixing it. Before sending the
new version I saw that report about a problem with dma_mask and I'm afraid
I did not send another version with the fix ...

Yao, can you try with next patch?:

*diff --git a/lib/librte_eal/common/eal_common_memory.c
b/lib/librte_eal/common/eal_common_memory.c*

*index ef656bbad..26adf46c0 100644*

*--- a/lib/librte_eal/common/eal_common_memory.c*

*+++ b/lib/librte_eal/common/eal_common_memory.c*

@@ -458,10 +458,6 @@ rte_eal_check_dma_mask(uint8_t maskbits)

                return -1;

        }



-       /* keep the more restricted maskbit */

-       if (!mcfg->dma_maskbits || maskbits < mcfg->dma_maskbits)

-               mcfg->dma_maskbits = maskbits;

-

        /* create dma mask */

        mask = ~((1ULL << maskbits) - 1);

On Mon, Oct 29, 2018 at 9:48 AM Thomas Monjalon <thomas@monjalon.net> wrote:

> 29/10/2018 10:36, Yao, Lei A:
> > From: Thomas Monjalon [mailto:thomas@monjalon.net]
> > > 29/10/2018 09:23, Yao, Lei A:
> > > > Hi, Lucero, Thomas
> > > >
> > > > This patch set will cause deadlock during memory initialization.
> > > > rte_memseg_walk and try_expand_heap both will lock
> > > > the file &mcfg->memory_hotplug_lock. So dead lock will occur.
> > > >
> > > > #0       rte_memseg_walk
> > > > #1  <-rte_eal_check_dma_mask
> > > > #2  <-alloc_pages_on_heap
> > > > #3  <-try_expand_heap_primary
> > > > #4  <-try_expand_heap
> > > >
> > > > Log as following:
> > > > EAL: TSC frequency is ~2494156 KHz
> > > > EAL: Master lcore 0 is ready (tid=7ffff7fe3c00;cpuset=[0])
> > > > [New Thread 0x7ffff5e0d700 (LWP 330350)]
> > > > EAL: lcore 1 is ready (tid=7ffff5e0d700;cpuset=[1])
> > > > EAL: Trying to obtain current memory policy.
> > > > EAL: Setting policy MPOL_PREFERRED for socket 0
> > > > EAL: Restoring previous memory policy: 0
> > > >
> > > > Could you have a check on this? A lot of test cases in our validation
> > > > team fail because of this. Thanks a lot!
> > >
> > > Can we just call rte_memseg_walk_thread_unsafe()?
> > >
> > > +Cc Anatoly
> >
> > Hi, Thomas
> >
> > I change to rte_memseg_walk_thread_unsafe(), still
> > Can't work.
> >
> > EAL: Setting policy MPOL_PREFERRED for socket 0
> > EAL: Restoring previous memory policy: 0
> > EAL: memseg iova 140000000, len 40000000, out of range
> > EAL:    using dma mask ffffffffffffffff
> > EAL: alloc_pages_on_heap(): couldn't allocate memory due to DMA mask
> > EAL: Trying to obtain current memory policy.
> > EAL: Setting policy MPOL_PREFERRED for socket 1
> > EAL: Restoring previous memory policy: 0
> > EAL: memseg iova 1bc0000000, len 40000000, out of range
> > EAL:    using dma mask ffffffffffffffff
> > EAL: alloc_pages_on_heap(): couldn't allocate memory due to DMA mask
> > error allocating rte services array
> > EAL: FATAL: rte_service_init() failed
> > EAL: rte_service_init() failed
> > PANIC in main():
>
> I think it is showing there are at least 2 issues:
>         1/ deadlock
>         2/ allocation does not comply with mask check (out of range)
>
>
>