Re: [Xenomai] Performance issue with memory allocators

[Steve Freyder <steve@freyder.net>]

On 6/14/2018 10:21 AM, Philippe Gerum wrote:
> On 06/14/2018 03:10 PM, Philippe Gerum wrote:
>> On 06/14/2018 12:53 AM, Steve Freyder wrote:
>>> I rebuilt my program with a 512K stack, same problem with the SEGV.
>>>
>>> Tried something different, without running my application at all, I ran
>>> this script:
>>>
>>> ulimit -c unlimited
>>> smokey --run=memory_pshared --verbose=2 --mem-pool-size=32M --session=foo
>>>
>>> it ran fine, but if I ran it a second time, without waiting for the
>>> first invocation to
>>> finish, then I got the same SEGV that I previously was seeing with my
>>> program and the
>>> traceback looks the same.
>>>
>>> It's as if there's an initialization issue when you're not the creator
>>> of the
>>> pshared heap.
>>>
>>>
>> Yeah, this can't work just yet. Implementation blunder. I'll follow up
>> on this.
>>
> Could you check if the situation gets any better with this change in?
>
> http://git.xenomai.org/xenomai-3.git/commit/?h=next&id=7e3d69ae6c9235289a8984b609ae2400ab950f17
>
> Thanks,
>
Philippe,

This looks pretty similar.  At first I thought my patching didn't fly, 
but I double-checked
my work and although the size of the "smokey" binary didn't change, the 
size of
libcopperplate DID change so the patch is there.

Core was generated by `smokey --run=memory_pshared --verbose=2 
--mem-pool-size=32M --session=foo'.
Program terminated with signal SIGSEGV, Segmentation fault.
#0  compare_range_by_size (r=0xfffcb000, l=0x741f38ec) at 
../../../../xenomai-3/lib/copperplate/heapobj-pshared.c:638
638     ../../../../xenomai-3/lib/copperplate/heapobj-pshared.c: No such 
file or directory.
[Current thread is 1 (LWP 800)]
(gdb) bt
#0  compare_range_by_size (r=0xfffcb000, l=0x741f38ec) at 
../../../../xenomai-3/lib/copperplate/heapobj-pshared.c:638
#1  search_range_by_size (avl=avl@entry=0x741f38ec, 
node=node@entry=0x7eca29d4, pdelta=0x7eca29c0,
     pdelta@entry=0x76f418fc <add_free_range+216>, dir=dir@entry=0) at 
../../../../xenomai-3/lib/copperplate/heapobj-pshared.c:640
#2  0x76f418fc in shavl_search_inner (ops=0x76f56630 <size_search_ops>, 
delta=0x76f418fc <add_free_range+216>, n=0x7eca29d4,
     avl=0x741f38ec) at 
../../../../xenomai-3/include/boilerplate/avl-inner.h:285
#3  shavl_search_nearest (ops=0x76f56630 <size_search_ops>, dir=1, 
node=0x7eca29d4, avl=0x741f38ec)
     at ../../../../xenomai-3/include/boilerplate/avl-inner.h:395
#4  shavl_search_ge (ops=0x76f56630 <size_search_ops>, node=0x7eca29d4, 
avl=0x741f38ec)
     at ../../../../xenomai-3/include/boilerplate/avl-inner.h:415
#5  find_suitable_range (size=1536, ext=0x741f38b8) at 
../../../../xenomai-3/lib/copperplate/heapobj-pshared.c:207
#6  reserve_page_range (size=1536, ext=0x741f38b8) at 
../../../../xenomai-3/lib/copperplate/heapobj-pshared.c:219
#7  add_free_range (heap=0x7eca29c0, heap@entry=0x741f3000, 
bsize=1995793968, bsize@entry=1536, log2size=1948200960, log2size@entry=0)
     at ../../../../xenomai-3/lib/copperplate/heapobj-pshared.c:432
#8  0x76f41be4 in sheapmem_alloc (heap=0x741f3000, size=size@entry=1272) 
at ../../../../xenomai-3/lib/copperplate/heapobj-pshared.c:553
#9  0x76f42a44 in xnmalloc (size=size@entry=1272) at 
../../../../xenomai-3/lib/copperplate/heapobj-pshared.c:1197
#10 0x76f3f8f4 in __threadobj_alloc 
(tcb_struct_size=tcb_struct_size@entry=248, 
wait_union_size=wait_union_size@entry=1024,
     thobj_offset=thobj_offset@entry=0) at 
../../../../xenomai-3/lib/copperplate/threadobj.c:1118
#11 0x76f407c0 in main_overlay () at 
../../../../xenomai-3/lib/copperplate/threadobj.c:1787
#12 threadobj_pkg_init (anon_session=anon_session@entry=0) at 
../../../../xenomai-3/lib/copperplate/threadobj.c:1818
#13 0x76f3da3c in copperplate_init () at 
../../../../xenomai-3/lib/copperplate/init.c:225
#14 0x76f1c5ac in __xenomai_init (argcp=0x7eca2bcc, 
argcp@entry=0x7eca2c14, argvp=0x1a7430, argvp@entry=0x7eca2c10,
     me=me@entry=0x76f244e0 "program") at 
../../../../xenomai-3/lib/boilerplate/setup.c:601
#15 0x76f1cd70 in xenomai_init (argcp=0x7eca2c14, 
argcp@entry=0x7eca2c0c, argvp=argvp@entry=0x7eca2c10)
     at ../../../../xenomai-3/lib/boilerplate/setup.c:656
#16 0x000149f0 in call_init (argvp=0x7eca2c10, argcp=0x7eca2c0c) at 
../../../../../xenomai-3/lib/boilerplate/init/bootstrap.c:105
#17 xenomai_bootstrap () at 
../../../../../xenomai-3/lib/boilerplate/init/bootstrap.c:169
#18 0x0002a334 in __libc_csu_init (argc=5, argv=0x7eca2da4, 
envp=0x7eca2dbc) at /usr/src/debug/glibc/2.23-r0/git/csu/elf-init.c:88
#19 0x41408088 in __libc_start_main () from /lib/libc.so.6
#20 0x00014c94 in _start () at ../sysdeps/arm/start.S:124
Backtrace stopped: previous frame identical to this frame (corrupt stack?)
(gdb)