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Subject: Re: [hwloc-devel] Something lighter-weight than XML?
From: Ralph Castain (rhc_at_[hidden])
Date: 2011-09-24 18:36:38


Thanks!

On Sep 24, 2011, at 2:18 PM, Brice Goglin wrote:

> I fixed one parsing bug in commit 3660 on the v1.2-ompi branch. Things
> should work better now.
>
> Parsing XML distance matrices was broken when the XML file came from the
> no-libxml exporter. That's why you had problems on your dual-amd machine
> (those have distance matrices) and not on your mac (single processor, no
> distances, no bug).
>
> The v1.2 branch doesn't report parsing failure well, so it just crashed.
> Trunk exits with an error instead of crashing.
>
> Brice
>
>
>
>
> Le 24/09/2011 20:37, Ralph Castain a écrit :
>> Yep, it fails. Runs on my Mac, but not under Linux.
>>
>> Program terminated with signal 11, Segmentation fault.
>> #0 0x00002aaaaacdbedd in hwloc_bitmap_snprintf () from /nfs/rinfs/san/homedirs/rhc/lib/libhwloc.so.3
>> (gdb) where
>> #0 0x00002aaaaacdbedd in hwloc_bitmap_snprintf () from /nfs/rinfs/san/homedirs/rhc/lib/libhwloc.so.3
>> #1 0x00002aaaaacdc060 in hwloc_bitmap_asprintf () from /nfs/rinfs/san/homedirs/rhc/lib/libhwloc.so.3
>> #2 0x00002aaaaacd9b34 in hwloc__xml_export_object () from /nfs/rinfs/san/homedirs/rhc/lib/libhwloc.so.3
>> #3 0x00002aaaaacda325 in hwloc___nolibxml_prepare_export () from /nfs/rinfs/san/homedirs/rhc/lib/libhwloc.so.3
>> #4 0x00002aaaaacda39c in hwloc__nolibxml_prepare_export () from /nfs/rinfs/san/homedirs/rhc/lib/libhwloc.so.3
>> #5 0x00002aaaaacda4be in hwloc_topology_export_xmlbuffer () from /nfs/rinfs/san/homedirs/rhc/lib/libhwloc.so.3
>> #6 0x00000000004009b8 in main () at xmlbuffer.c:31
>>
>> On Sep 24, 2011, at 9:45 AM, Brice Goglin wrote:
>>
>>> Indeed, this object contains invalid pointers.
>>>
>>> Can you try to run tests/xmlbuffer.c from hwloc's tree? It does
>>> export+import+export+compare on the same machine. It would be good to
>>> know if it fails on one of the machines you're using here.
>>>
>>> https://svn.open-mpi.org/trac/hwloc/browser/branches/v1.2-ompi/tests/xmlbuffer.c?rev=3837&format=txt
>>>
>>> thanks
>>> Brice
>>>
>>>
>>>
>>> Le 24/09/2011 17:07, Ralph Castain a écrit :
>>>> FWIW: I tried just printing out the contents of that root object immediately after importing the xml, and it clearly has a problem:
>>>>
>>>> (gdb) print *obj
>>>> $2 = {type = OPAL_HWLOC122_hwloc_OBJ_SYSTEM, os_index = 0, name = 0x101 <Address 0x101 out of bounds>, memory = {
>>>> total_memory = 46912502995240, local_memory = 46912502995240, page_types_len = 0, page_types = 0x0}, attr = 0x2,
>>>> depth = 6900112, logical_index = 0, os_level = 6571424, next_cousin = 0x0, prev_cousin = 0xffffffff, parent = 0x0,
>>>> sibling_rank = 0, next_sibling = 0x0, prev_sibling = 0x0, arity = 145, children = 0x2aaaab139738,
>>>> first_child = 0x2aaaab139738, last_child = 0x0, userdata = 0x0, cpuset = 0x0, complete_cpuset = 0x0,
>>>> online_cpuset = 0x644700, allowed_cpuset = 0x691970, nodeset = 0x6919e0, complete_nodeset = 0x644c90,
>>>> allowed_nodeset = 0x644cb0, distances = 0x6948b0, distances_count = 6900000, infos = 0x0, infos_count = 0}
>>>>
>>>>
>>>> On Sep 24, 2011, at 9:02 AM, Ralph Castain wrote:
>>>>
>>>>> Here's the trace:
>>>>>
>>>>> #0 0x00002aaaaae61737 in hwloc__xml_export_object (output=0x7fffffffd890, topology=0x695f10, obj=0x2aaaab139b28)
>>>>> at topology-xml.c:1094
>>>>> #1 0x00002aaaaae61b69 in hwloc___nolibxml_prepare_export (topology=0x695f10,
>>>>> xmlbuffer=0x698a70 "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n<!DOCTYPE topology SYSTEM \"hwloc.dtd\">\n<topology>\n <object type=\"Unknown\" os_level=\"-1424778408\" os_index=\"10922\" cpuset=\"0xf...f\" complete_cpuset=\"0xf...f\" onl"...,
>>>>> buflen=16384) at topology-xml.c:1193
>>>>> #2 0x00002aaaaae61be0 in hwloc__nolibxml_prepare_export (topology=0x695f10, bufferp=0x7fffffffd988, buflenp=0x7fffffffd97c)
>>>>> at topology-xml.c:1207
>>>>> #3 0x00002aaaaae61d02 in opal_hwloc122_hwloc_topology_export_xmlbuffer (topology=0x695f10, xmlbuffer=0x7fffffffd988,
>>>>> buflen=0x7fffffffd97c) at topology-xml.c:1281
>>>>> #4 0x00002aaaaae529f4 in opal_hwloc_compare (topo1=0x695f10, topo2=0x6915c0, type=22 '\026') at base/hwloc_base_dt.c:183
>>>>> #5 0x00002aaaaadf348c in opal_dss_compare (value1=0x695f10, value2=0x6915c0, type=22 '\026') at dss/dss_compare.c:39
>>>>> #6 0x00002aaaaad9b5f7 in process_orted_launch_report (fd=-1, event=1, data=0x6444d0) at base/plm_base_launch_support.c:564
>>>>> #7 0x00002aaaaae3881f in event_process_active_single_queue (base=0x60dd60, activeq=0x6111e0) at event.c:1329
>>>>> #8 0x00002aaaaae38c71 in event_process_active (base=0x60dd60) at event.c:1396
>>>>> #9 0x00002aaaaae3902b in opal_libevent2012_event_base_loop (base=0x60dd60, flags=1) at event.c:1598
>>>>> #10 0x00002aaaaadf080d in opal_progress () at runtime/opal_progress.c:189
>>>>> #11 0x00002aaaaad9bbfa in orte_plm_base_daemon_callback (num_daemons=2) at base/plm_base_launch_support.c:666
>>>>> #12 0x00002aaaaada49e1 in plm_slurm_launch_job (jdata=0x67a500) at plm_slurm_module.c:404
>>>>> #13 0x0000000000403822 in orterun (argc=4, argv=0x7fffffffe1d8) at orterun.c:817
>>>>> #14 0x0000000000402aa3 in main (argc=4, argv=0x7fffffffe1d8) at main.c:13
>>>>>
>>>>> And the error report
>>>>>
>>>>> Program received signal SIGSEGV, Segmentation fault.
>>>>> 0x00002aaaaae61737 in hwloc__xml_export_object (output=0x7fffffffd890, topology=0x695f10, obj=0x2aaaab139b28)
>>>>> at topology-xml.c:1094
>>>>> 1094 sprintf(tmp, "%llu", (unsigned long long) obj->memory.page_types[i].count);
>>>>> (gdb) print obj
>>>>> $1 = (opal_hwloc122_hwloc_obj_t) 0x2aaaab139b28
>>>>> (gdb) print *obj
>>>>> $2 = {type = 2870188824, os_index = 10922, name = 0x2aaaab139b18 "\b\233\023\253\252*", memory = {total_memory = 6579376,
>>>>> local_memory = 6579376, page_types_len = 2870188856, page_types = 0x2aaaab139b38}, attr = 0x2aaaab139b48,
>>>>> depth = 2870188872, logical_index = 10922, os_level = -1424778408, next_cousin = 0x2aaaab139b58,
>>>>> prev_cousin = 0x2aaaab139b68, parent = 0x2aaaab139b68, sibling_rank = 2870188920, next_sibling = 0x2aaaab139b78,
>>>>> prev_sibling = 0x2aaaab139b88, arity = 2870188936, children = 0x2aaaab139b98, first_child = 0x2aaaab139b98,
>>>>> last_child = 0x2aaaab139ba8, userdata = 0x2aaaab139ba8, cpuset = 0x2aaaab139bb8, complete_cpuset = 0x2aaaab139bb8,
>>>>> online_cpuset = 0x2aaaab139bc8, allowed_cpuset = 0x2aaaab139bc8, nodeset = 0x2aaaab139bd8,
>>>>> complete_nodeset = 0x2aaaab139bd8, allowed_nodeset = 0x2aaaab139be8, distances = 0x2aaaab139be8,
>>>>> distances_count = 2870189048, infos = 0x2aaaab139bf8, infos_count = 2870189064}
>>>>> (gdb) print obj->memory
>>>>> $3 = {total_memory = 6579376, local_memory = 6579376, page_types_len = 2870188856, page_types = 0x2aaaab139b38}
>>>>> (gdb) print obj->memory.page_types
>>>>> $4 = (struct opal_hwloc122_hwloc_obj_memory_page_type_s *) 0x2aaaab139b38
>>>>> (gdb) print i
>>>>> $5 = 1612
>>>>> (gdb) print obj->memory.page_types[1600]
>>>>> $6 = {size = 0, count = 0}
>>>>> (gdb) print obj->memory.page_types[1612]
>>>>> Cannot access memory at address 0x2aaaab13fff8
>>>>> (gdb) print obj->memory.page_types[1611]
>>>>> $7 = {size = 0, count = 0}
>>>>> (gdb)
>>>>>
>>>>>
>>>>> The whole obj looks like trash to me. I looked a little more - the object referenced is the root object:
>>>>>
>>>>> 1193 hwloc__xml_export_object (&output, topology, hwloc_get_root_obj(topology));
>>>>>
>>>>> I'm continuing to look in case I'm doing something stupid, but the code is pretty linear here - unpack, import, export for compare.
>>>>>
>>>>>
>>>>> On Sep 24, 2011, at 8:59 AM, Jeff Squyres wrote:
>>>>>
>>>>>> Here's some feedback from Ralph -- any idea what's going wrong here?
>>>>>>
>>>>>> -----
>>>>>>
>>>>>> 1. I export a topology into xml using
>>>>>>
>>>>>> hwloc_topology_export_xmlbuffer(t, &xmlbuffer, &len);
>>>>>>
>>>>>> I then pack and send the string.
>>>>>>
>>>>>> 2. I unpack the string on the other end and import it into a topology
>>>>>> hwloc_topology_init(&t);
>>>>>> if (0 != (rc = hwloc_topology_set_xmlbuffer(t, xmlbuffer, strlen(xmlbuffer)))) {
>>>>>> hwloc_topology_destroy(t);
>>>>>> goto cleanup;
>>>>>> }
>>>>>> hwloc_topology_load(t);
>>>>>>
>>>>>> 3. I then need to compare two topologies, so I export the topology I received into another xml string
>>>>>> hwloc_topology_export_xmlbuffer(t1, &x1, &l1);
>>>>>>
>>>>>> It is this export that fails, which implies to me that somehow the import didn't work right. Note that this code worked fine with libxml2, so this is a regression.
>>>>>>
>>>>>>
>>>>>> On Sep 22, 2011, at 9:39 AM, Jeff Squyres wrote:
>>>>>>
>>>>>>> Yes, I can get some testing of the ompi branch pretty quickly. I can bring in a new copy of this later today and see what we can see.
>>>>>>>
>>>>>>> Many thanks!
>>>>>>>
>>>>>>>
>>>>>>> On Sep 19, 2011, at 9:05 AM, Brice Goglin wrote:
>>>>>>>
>>>>>>>> I pushed the new minimalistic XML import/export implementation without
>>>>>>>> libxml2 to the nolibxml branch. If libxml2 is available, it's still used
>>>>>>>> by default. --disable-libxml2 or some env variables can be used for
>>>>>>>> force the minimalistic implementation if needed. The minimalistic implem
>>>>>>>> is only guaranteed to import XML files that were generated by hwloc
>>>>>>>> (even if libxml was enabled there).
>>>>>>>>
>>>>>>>> I also backported most of this to the new v1.2-ompi branch (required to
>>>>>>>> backport some other XML cleanups from trunk). This branch will now serve
>>>>>>>> as a base for Open MPI's embedded hwloc. The idea is to have a complete
>>>>>>>> v1.2 + nolibxml somewhere so that we can at least run make check (Open
>>>>>>>> MPI does not embed enough to run hwloc's make check).
>>>>>>>>
>>>>>>>> How do we proceed now? Can we have the OMPI guys test the new code soon?
>>>>>>>> Should I wait for their feedback before merging the nolibxml branch into
>>>>>>>> the trunk? I'd like to merge this in v1.3 too (and basically release rc2
>>>>>>>> as the actual first feature-complete RC), so getting feedback early
>>>>>>>> might be appreciated.
>>>>>>>>
>>>>>>>> Brice
>>>>>>>>
>>>>>>>> _______________________________________________
>>>>>>>> hwloc-devel mailing list
>>>>>>>> hwloc-devel_at_[hidden]
>>>>>>>> http://www.open-mpi.org/mailman/listinfo.cgi/hwloc-devel
>>>>>>> --
>>>>>>> Jeff Squyres
>>>>>>> jsquyres_at_[hidden]
>>>>>>> For corporate legal information go to:
>>>>>>> http://www.cisco.com/web/about/doing_business/legal/cri/
>>>>>>>
>>>>>>>
>>>>>>> _______________________________________________
>>>>>>> hwloc-devel mailing list
>>>>>>> hwloc-devel_at_[hidden]
>>>>>>> http://www.open-mpi.org/mailman/listinfo.cgi/hwloc-devel
>>>>>> --
>>>>>> Jeff Squyres
>>>>>> jsquyres_at_[hidden]
>>>>>> For corporate legal information go to:
>>>>>> http://www.cisco.com/web/about/doing_business/legal/cri/
>>>>>>
>>>> _______________________________________________
>>>> hwloc-devel mailing list
>>>> hwloc-devel_at_[hidden]
>>>> http://www.open-mpi.org/mailman/listinfo.cgi/hwloc-devel
>