Re: [PATCH 00 of 10 v3] Automatic NUMA placement for xl

[Ian Campbell <Ian.Campbell@citrix.com>]

On Wed, 2012-07-04 at 17:17 +0100, Dario Faggioli wrote:
> Hello,
> 
> Third version of the NUMA placement series Xen 4.2.

I'm afraid I get a segfault with this:

        quartz:~# xl dest d32-1 ; gdb --args xl cr /etc/xen/debian-x86_32p-1
        [...]
        (gdb) r
        Starting program: /usr/sbin/xl cr /etc/xen/debian-x86_32p-1
        [Thread debugging using libthread_db enabled]
        Parsing config from /etc/xen/debian-x86_32p-1
        
        Program received signal SIGSEGV, Segmentation fault.
        *__GI___libc_free (mem=0x1) at malloc.c:3710
        3710	malloc.c: No such file or directory.
        	in malloc.c
        (gdb) bt
        #0  *__GI___libc_free (mem=0x1) at malloc.c:3710
        #1  0xb7fa8b78 in libxl_bitmap_dispose (map=0xbffff170) at libxl_utils.c:510
        #2  0xb7fadbde in libxl__get_numa_candidates (gc=0x806b7a0, min_free_memkb=141312, min_cpus=4, min_nodes=0, max_nodes=0, suitable_cpumap=0xbffff1f4, cndts=0xbffff208, nr_cndts=0xbffff20c) at libxl_numa.c:397
        #3  0xb7fa45ec in numa_place_domain (gc=0x806b7a0, domid=8, info=0xbffff5dc, state=0x806a954) at libxl_dom.c:169
        #4  libxl__build_pre (gc=0x806b7a0, domid=8, info=0xbffff5dc, state=0x806a954) at libxl_dom.c:232
        #5  0xb7f98234 in libxl__domain_build (gc=0x806b7a0, info=0xbffff5dc, domid=8, state=0x806a954) at libxl_create.c:320
        #6  0xb7f9859f in domcreate_bootloader_done (egc=0xbffff43c, bl=0x806a998, rc=0) at libxl_create.c:695
        #7  0xb7fb5e50 in bootloader_callback (egc=<value optimized out>, bl=0x806a998, rc=0) at libxl_bootloader.c:256
        #8  0xb7fb7482 in libxl__bootloader_run (egc=0xbffff43c, bl=0x806a998) at libxl_bootloader.c:394
        #9  0xb7f99535 in initiate_domain_create (ctx=<value optimized out>, d_config=<value optimized out>, domid=0x8068354, restore_fd=-1, ao_how=0x0, aop_console_how=0x0) at libxl_create.c:635
        #10 do_domain_create (ctx=<value optimized out>, d_config=<value optimized out>, domid=0x8068354, restore_fd=-1, ao_how=0x0, aop_console_how=0x0) at libxl_create.c:1039
        #11 0xb7f9966f in libxl_domain_create_new (ctx=0x8069030, d_config=0xbffff5ac, domid=0x8068354, ao_how=0x0, aop_console_how=0x0) at libxl_create.c:1062
        #12 0x0805c479 in create_domain (dom_info=<value optimized out>) at xl_cmdimpl.c:1809
        #13 0x0805dd13 in main_create (argc=2, argv=0xbffffd28) at xl_cmdimpl.c:3774
        #14 0x0804d1d6 in main (argc=3, argv=0xbffffd24) at xl.c:263
        (gdb) frame 1
        #1  0xb7fa8b78 in libxl_bitmap_dispose (map=0xbffff170) at libxl_utils.c:510
        510	libxl_utils.c: No such file or directory.
        	in libxl_utils.c
        (gdb) print *map
        $2 = {size = 3221221764, map = 0x1 <Address 0x1 out of bounds>}
        (gdb) frame 2
        #2  0xb7fadbde in libxl__get_numa_candidates (gc=0x806b7a0, min_free_memkb=141312, min_cpus=4, min_nodes=0, max_nodes=0, suitable_cpumap=0xbffff1f4, cndts=0xbffff208, nr_cndts=0xbffff20c) at libxl_numa.c:397
        397	libxl_numa.c: No such file or directory.
        	in libxl_numa.c
        (gdb) print suitable_nodemap
        $3 = {size = 3221221764, map = 0x1 <Address 0x1 out of bounds>}
        (gdb) print nodemap
        $4 = {size = 0, map = 0x0}
        
So it looks like suitable_nodemap wasn't initialised?

There are a few "goto out"s before initialising that variable, but none
of them log (really they should) and I didn't investigate which one it
was yet.

Ian.