Project isn’t available, but I can try to catch it in the act since it’s 
occurring regularly. I’ll reply to you directly if / when I’m able to set that 
up. Thx!

From: Vlad Brezae [mailto:vlb...@microsoft.com]
Sent: Wednesday, October 19, 2016 5:20 PM
To: David Evans <dev...@pacificbiosciences.com>
Cc: mono-devel-l...@lists.ximian.com
Subject: Re: [Mono-dev] xbuild crash with mono 4.6.1?

Hey David,

          Would it be possible to repro this issue ? Is this project available 
somewhere ?

          If it’s not an OOM issue, then additional debugging would be 
required. Judging from the stacktrace and source code, 
mono_valloc/mono_valloc_aligned fails for whatever reason. Either desc is 
corrupted (it would be useful to know the contents of the memory there) and we 
are trying to allocate invalid amounts of memory, or the mmap behind the scenes 
fails for other reasons (in which case it would be useful to know the errno 
value). This information should not be too hard to find by attaching with 
lldb/gdb (MONO_DEBUG=suspend-on-sigsegv can be passed if the debugger does not 
attach automatically).

         Ideally it would be nice to see this crash myself, but I’m not sure 
whether this is possible.

Thanks,
    Vlad

From: David Evans 
<dev...@pacificbiosciences.com<mailto:dev...@pacificbiosciences.com>>
Date: Thursday, 20 October 2016 at 02:20
To: Vlad Brezae <vlb...@microsoft.com<mailto:vlb...@microsoft.com>>, mono-devel 
<mono-devel-l...@lists.ximian.com<mailto:mono-devel-l...@lists.ximian.com>>
Subject: RE: [Mono-dev] xbuild crash with mono 4.6.1?

Thanks, Vlad. I did check that first and though xbuild uses an insane amount of 
memory there still was tons left when it crashed. I did some profiling 
yesterday to confirm and it’s crashing when there are still gigs of physical 
memory available plus all of the swap. Which is why I suspected some kind of 
heap corruption as a more likely cause.

I just noticed that I was testing against the 4.6.1.3 source package, I can try 
4.6.1.5 as well. I can also try earlier builds of 4.x to see where it might 
have been introduced, but that will take me some time. Sounds like this is not 
a known issue to folks here?

I did just find two open Bugzilla reports that looks similar but not exactly 
the same, against 4.6.0, but without any resolution or diagnosis yet. I just 
added notes to these:
https://bugzilla.xamarin.com/show_bug.cgi?id=44970<https://na01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fbugzilla.xamarin.com%2Fshow_bug.cgi%3Fid%3D44970&data=02%7C01%7Cvlbrez%40microsoft.com%7C287cc06842014c1ff04208d3f8769131%7C72f988bf86f141af91ab2d7cd011db47%7C1%7C0%7C636125160576297146&sdata=qNTGZQE135jdbEEK2SgRXWpSXSqRtRWLTRF5ngWLG3E%3D&reserved=0>

And also this building in XS reported for 4.6.0:
https://bugzilla.xamarin.com/show_bug.cgi?id=44355<https://na01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fbugzilla.xamarin.com%2Fshow_bug.cgi%3Fid%3D44355&data=02%7C01%7Cvlbrez%40microsoft.com%7C287cc06842014c1ff04208d3f8769131%7C72f988bf86f141af91ab2d7cd011db47%7C1%7C0%7C636125160576297146&sdata=Ut%2BWG3PRQxhrsrOfzdx0NxQ5l2jb2%2BvLREAJhkDXBDE%3D&reserved=0>

Thanks,
David

From: Vlad Brezae [mailto:vlb...@microsoft.com]
Sent: Tuesday, October 18, 2016 2:11 PM
To: David Evans 
<dev...@pacificbiosciences.com<mailto:dev...@pacificbiosciences.com>>; 
mono-devel 
<mono-devel-l...@lists.ximian.com<mailto:mono-devel-l...@lists.ximian.com>>
Subject: Re: [Mono-dev] xbuild crash with mono 4.6.1?

Hello David,

    Based on the crash site, it would seem that we fail to allocate memory from 
the OS, which means we have an OOM situation, which we poorly handle as of 
right now.

     Could you check whether this is the case, whether there are mono instances 
that use more memory than expected. You could consider trying to limit the heap 
from growing too much by passing MONO_GC_PARAMS=soft-heap-limit=<heap_limit>, 
unless something is leaking.

Vlad

From: Mono-devel-list 
<mono-devel-list-boun...@lists.dot.net<mailto:mono-devel-list-boun...@lists.dot.net>>
 on behalf of David Evans 
<dev...@pacificbiosciences.com<mailto:dev...@pacificbiosciences.com>>
Date: Tuesday, 18 October 2016 at 20:50
To: mono-devel 
<mono-devel-l...@lists.ximian.com<mailto:mono-devel-l...@lists.ximian.com>>
Subject: [Mono-dev] xbuild crash with mono 4.6.1?

I just started building and testing with mono 4.6.1 and I’m seeing an 
intermittent crash (memory corruption?) now during the build. Happens for me 
about one time out of ten. Anyone else seeing this or is there a solution 
already available that I could patch with? We have a fairly large project which 
uses a lot of memory, but I haven’t seen anything like this building with 
4.0.4.1 or when I tried out 4.2.x or 4.3.x Thanks!

Appears to be crashing in sgen when allocating, hence my corruption guess.
Full traces here:
http://pastebin.com/vQ4630Dv<https://na01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fpastebin.com%2FvQ4630Dv&data=02%7C01%7Cvlbrez%40microsoft.com%7C14c7f03e35954cd37bf608d3f77f5695%7C72f988bf86f141af91ab2d7cd011db47%7C1%7C0%7C636124098705789846&sdata=E8axBm%2BOnKauibPynBuXu4En5X9%2FrCvIWJewgApwlJA%3D&reserved=0>

_______________________________________________
Mono-devel-list mailing list
Mono-devel-list@lists.dot.net
http://lists.dot.net/mailman/listinfo/mono-devel-list

Reply via email to