domU reboot claim failed

[Jason Andryuk <jason.andryuk@xxxxxxx>]

Hi,

We're running Android as a guest and it's running the Compatibility Test 
Suite.  During the CTS, the Android domU is rebooted multiple times.
In the middle of the CTS, we've seen reboot fail.  xl -vvv shows:
domainbuilder: detail: Could not allocate memory for HVM guest as we 
cannot claim memory!
xc: error: panic: xg_dom_boot.c:119: xc_dom_boot_mem_init: can't 
allocate low memory for domain: Out of memory
libxl: error: libxl_dom.c:581:libxl__build_dom: xc_dom_boot_mem_init 
failed: Cannot allocate memory
domainbuilder: detail: xc_dom_release: called

So the claim failed.  The system has enough memory since we're just 
rebooting the same VM.  As a work around, I added sleep(1) + retry, 
which works.
The curious part is the memory allocation.  For d2 to d5, we have:
domainbuilder: detail: range: start=0x0 end=0xf0000000
domainbuilder: detail: range: start=0x100000000 end=0x1af000000
xc: detail: PHYSICAL MEMORY ALLOCATION:
xc: detail:   4KB PAGES: 0x0000000000000000
xc: detail:   2MB PAGES: 0x00000000000006f8
xc: detail:   1GB PAGES: 0x0000000000000003

But when we have to retry the claim for d6, there are no 1GB pages used:
domainbuilder: detail: range: start=0x0 end=0xf0000000
domainbuilder: detail: range: start=0x100000000 end=0x1af000000
domainbuilder: detail: HVM claim failed! attempt 0
xc: detail: PHYSICAL MEMORY ALLOCATION:
xc: detail:   4KB PAGES: 0x0000000000002800
xc: detail:   2MB PAGES: 0x0000000000000ce4
xc: detail:   1GB PAGES: 0x0000000000000000

But subsequent reboots for d7 and d8 go back to using 1GB pages.

Does the change in memory allocation stick out to anyone?

Unfortunately, I don't have insight into what the failing test is doing.

Xen doesn't seem set up to track the claim across reboot.  Retrying the 
claim works in our scenario since we have a controlled configuration.
Thanks,
Jason