Created attachment 427367 [details]
xend.log

Description of problem:
When trying to balloon up RHEL 6 PV guest to a larger memory size, the guest just stays in the memory size with which it is created. 

Version-Release number of selected component (if applicable):
kernel-xen-devel-2.6.18-194.3.1.el5
xen-libs-3.0.3-113.el5
xen-debuginfo-3.0.3-113.el5
xen-devel-3.0.3-113.el5
kernel-xen-2.6.18-194.3.1.el5
xen-3.0.3-113.el5


How reproducible:
Always

Steps to Reproduce:

1. # xm li
Name                                      ID Mem(MiB) VCPUs State   Time(s)
Domain-0                                   0     1024     4 r-----  18081.7
vm1                                       56      512     4 -b----      1.0

2. # xm info | grep mem
total_memory           : 4029
free_memory            : 2385

3. # xm li -l 56 | grep mem
    (memory 512)
    (shadow_memory 0)
    (maxmem 1024)

4. # xm mem-set 56 800

5. # xm li -l 56 | grep mem
    (memory 800)
    (shadow_memory 0)
    (maxmem 1024)

6. # xm li
Name                                      ID Mem(MiB) VCPUs State   Time(s)
Domain-0                                   0     1024     4 r-----  18086.4
vm1                                       56      512     4 -b----      7.3

Within the guest, memory size is reported as 490M.

7. # xm info | grep mem
total_memory           : 4029
free_memory            : 2385
  
Actual results:
RHEL 6 PV guest cannot be ballooned beyond the memory size with which it is created.


Expected results:
Guest could be ballooned to any memory size below maxmem as along as there are enough free memory.

Additional info:
BTW, within RHEL 6 PV guest, directory of /proc/xen/ is empty which makes it difficult for us to get information of PV guest. Is it expected?