Hi Konrad & Jeremy:

            I think we finally located the missing patch for this commit.
            We test commit http://git.kernel.org/?p=linux/kernel/git/jeremy/xen.git;a=commit;h=c97f681f138039425c87f35ea46a92385d81e70e
            which is works.
 
            We test commit http://git.kernel.org/?p=linux/kernel/git/jeremy/xen.git;a=commit;h=221c64dbf860d37f841f40893bddf8d804aa55bd
            which server crashed.
 
             Later I found the comments for this commit: 
             http://git.kernel.org/?p=linux/kernel/git/jeremy/xen.git;a=commit;h=64141da587241301ce8638cc945f8b67853156ec
         
            So It looks like this fix is not applied on 2.6.32.36, Could you take a look at this? 
 
            Many thanks.
              
=====================================================
>Hi Konrad & Jeremy:
> 
>     I'd like to open this BUG in a new thread, since the old thread is too long for easy read.
>     
>     We recently want to upgrade our kernel to 2.6.32, but unfortunately, we confront a kernel crash bug.
>Our test case is simple, start 24 win2003 HVMS on our physical machine, and each HVM reboot 
>every 15minutes. The kernel will crash in half an hour.(That is crash on VM second starts).
> 
>Our test go much further.
>We test different kernel version.
>2.6.32.10  http://git.kernel.org/?p=linux/kernel/git/jeremy/xen.git;a=commit;h=d945b014ac5df9592c478bf9486d97e8914aab59
>2.6.32.11  http://git.kernel.org/?p=linux/kernel/git/jeremy/xen.git;a=commit;h=27f948a3bf365a5bc3d56119637a177d41147815
>2.6.32.12  http://git.kernel.org/?p=linux/kernel/git/jeremy/xen.git;a=commit;h=ba739f9abd3f659b907a824af1161926b420a2ce
>2.6.32.13  http://git.kernel.org/?p=linux/kernel/git/jeremy/xen.git;a=commit;h=f6fe6583b77a49b569eef1b66c3d761eec2e561b
>2.6.32.15  http://git.kernel.org/?p=linux/kernel/git/jeremy/xen.git;a=commit;h=27ed1b0e0dae5f1d5da5c76451bc84cb529128bd
>2.6.32.21  http://git.kernel.org/?p=linux/kernel/git/jeremy/xen.git;a=commit;h=69e50db231723596ed8ef9275d0068d6697f466a
> 
>There are basic three different result we met.
> 
>i1) grant table issue
>The host still function, but use xm  dmesg, we have abnormal log.
>please refer to the attched log of grant table
> 
>i2) kernel crash on a different place.
>Host die during the test, after reboot, we can see nothing abnormal in /var/log/messages
> 
>i3) kernel BUG at arch/x86/xen/mmu.c:1872; 
>Host die during the test, after reboot, we see the crash log in messages, refer to the attached log of 2.6.32.36
>Summary of the test result, can be classified in two:
> 
>1) 2.6.32.10
>30 machines involved the test, and three has issue (i1), and two has issue (i2), *no* issue (i3)
>Other machines run tests successfully till now, more than 8 hours
> 
>2)2.6.32.11 or later version.
>Each version containers 10 machine for tests, and all machine crashed in less than half an hour.
> 
>Conclusion:
>1) grant table issue exists in all kernel version
>2) kernerl crash at different place may exist in all kernel versions, but not happen so frequently, 2 out of 30
>3) We observe the major difference of issue i3), from the test, it looks like it is introduced between the version
>2.6.32.10 and 2.6.32.11.
> 
>Hope this help to locate the bug.
>Many thanks.
> 
>