hi,
I tried to make huge page request in Fedora x86_64 PV guest using xen 4.1 unstable and it crashed(crash info given below)
I had enabled superpages in config file
I had also set hugepages parameter at boot time for the PV Dom U
By excuting
# cat /proc/mem_info | grep Huge
gave me that there are 10 free huge pages available , still the domain crashed.
[   86.403654] BUG: unable to handle kernel paging request at ffff880002b35cb0
[   86.403695] IP: [<ffffffff8100505a>] xen_set_pte+0x47/0x52
[   86.403725] PGD 1a43067 PUD 1a47067 PMD 3e58067 PTE 8010000002b35065
[   86.403755] Oops: 0003 [#1] SMP 
[   86.403773] last sysfs file: /sys/devices/virtual/vc/vcsa6/
uevent
[   86.403791] CPU 0 
[  
 86.403800] Modules linked in: ip6t_REJECT nf_conntrack_ipv6 
ip6table_filter ip6_tables ipv6 xen_netfront xen_blkfront [last 
unloaded: scsi_wait_scan]
[   86.403859] 
[   86.403872] Pid: 759, comm: sohuge Not tainted 2.6.35.6-45.fc14.x86_64 #1 /
[   86.403888] RIP: e030:[<ffffffff8100505a>]  [<ffffffff8100505a>] xen_set_pte+0x47/0x52
[   86.403913] RSP: e02b:ffff88001cf43d38  EFLAGS: 00010296
[   86.403928] RAX: 0000000000000000 RBX: ffff880002b35cb0 RCX: 8000000140f750e7
[   86.403945] RDX: 0000000000000000 RSI: 8000000140f750e7 RDI: ffff880002b35cb0
[   86.403964] RBP: ffff88001cf43d58 R08: 0000000000000200 R09: ffff880002642128
[   86.403982] R10: 0000000000000022 R11: 0000000000000246 R12: 8000000140f750e7
[   86.404000] R13: 000000000001e74d R14: ffff88001ec8e680 R15: ffff88001e50dd00
[   86.404026] FS:  00007f0672be1720(0000) GS:ffff880003e99000(0000) knlGS:0000000000000000
[   86.404048] CS:  e033 DS: 0000 ES: 0000 CR0: 000000008005003b
[   86.404068] CR2: ffff880002b35cb0 CR3: 00000000025cd000 CR4: 0000000000002660
[   86.404071] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[   86.404071] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
[   86.404071] Process sohuge (pid: 759, threadinfo ffff88001cf42000, task ffff88001e50dd00)
[   86.404071] Stack:
[   86.404071]  ffff8800025c9a10 ffff880002b35cb0 8000000140f750e7 00007f0672c00000
[   86.404071] <0> ffff88001cf43db8 ffffffff8100514a 0000000000000022 ffff880002642128
[   86.404071] <0> 0000000000000200 8000000002800027 8000000000000027 ffff8800025c9a10
[   86.404071] Call Trace:
[   86.404071]  [<ffffffff8100514a>] xen_set_pte_at+0xe5/0xf4
[   86.404071]  [<ffffffff810fc62e>] set_huge_pte_at+0xe/0x12
[   86.404071]  [<ffffffff810fec42>] hugetlb_fault+0x380/0x510
[   86.404071]  [<ffffffff810eba12>] handle_mm_fault+0xbd/0x84d
[   86.404071]  [<ffffffff8100670f>] ? xen_restore_fl_direct_end+0x0/0x1
[   86.404071]  [<ffffffff812aad54>] ? raw_local_irq_restore+0x10/0x12
[   86.404071]  [<ffffffff8146c468>] do_page_fault+0x250/0x265
[   86.404071]  [<ffffffff814697f5>] page_fault+0x25/0x30
[   
86.404071] Code: ff ff 05 be 00 ca 00 e8 aa ff ff ff 44 8b 2d ba 00 ca 
00 e8 48 6f 02 00 ff c8 0f 94 c0 0f b6 c0 46 8d 2c 28 44 89 2d a2 00 ca 
00 <4c> 89 23 5a 5b 41 5c 41 5d c9 c3 55 48 89 e5 41 57 41 56 41 
55 
[   86.404071] RIP  [<ffffffff8100505a>] xen_set_pte+0x47/0x52
[   86.404071]  RSP <ffff88001cf43d38>
[   86.404071] CR2: ffff880002b35cb0
[   86.404071] ---[ end trace b6fd430c22cc2dfc ]---
Message from syslogd@localhost at Jan  8 23:05:21 ...
 kernel:[   86.403755] Oops: 0003 [#1] SMP 
Message from syslogd@localhost at Jan  8 23:05:21 ...
 kernel:[   86.403773] last sysfs file: /sys/devices/virtual/vc/vcsa6/uevent
Message from syslogd@localhost at Jan  8 23:05:21 ...
 kernel:[   86.404071] Stack:
Message from syslogd@localhost at Jan  8 23:05:21 ...
 kernel:[   86.404071] Call Trace:
Message from syslogd@localhost at Jan  8 23:05:21 ...
 kernel:[  
 86.404071] Code: ff ff 05 be 00 ca 00 e8 aa ff ff ff 44 8b 2d ba 00 ca 
00 e8 48 6f 02 00 ff c8 0f 94 c0 0f b6 c0 46 8d 2c 28 44 89 2d a2 00 ca 
00 <4c> 89 23 5a 5b 41 5c 41 5d c9 c3 55 48 89 e5 41 57 41 56 41 
55 
Message from syslogd@localhost at Jan  8 23:05:21 ...
 kernel:[   86.404071] CR2: ffff880002b35cb0
can anyone tell the way problem can be solved ?
-
Keshav Darak.