ציטוט Ryota OZAKI:
Hi Izik,
I've tried your patch set, but ksm doesn't work in my machine.
I compiled linux patched with the four patches and configured with KSM
and KVM enabled. After boot with the linux, I run two VMs running linux
using QEMU with a patch in your mail and started KSM scanner with your
script, then the host linux caused panic with the following oops.
Yes you are right, we are missing pte_unmap(pte); in get_pte()!
that will effect just 32bits with highmem so this why you see it
thanks for the reporting, i will fix it for v3
below patch should fix it (i cant test it now, will test it for v3)
can you report if it fix your problem? thanks
== BEGINNING of OOPS
kernel BUG at arch/x86/mm/highmem_32.c:87!
invalid opcode: 0000 [#1] SMP
last sysfs file: /sys/class/net/vnet-ssh2/address
Dumping ftrace buffer:
(ftrace buffer empty)
Modules linked in: netconsole autofs4 nf_conntrack_ipv4 nf_defrag_ipv4
xt_state nf_conntrack xt_tcpudp ipt_REJECT iptable_filter ip_tables
x_tables loop kvm_intel kvm iTCO_wdt iTCO_vendor_support igb
netxen_nic button ext3 jbd mbcache uhci_hcd ohci_hcd ehci_hcd usbcore
[last unloaded: microcode]
Pid: 343, comm: kksmd Not tainted
(2.6.28-rc5-linus-head-20081119-sparsemem #1) X7DWA
EIP: 0060:[<c041eff9>] EFLAGS: 00010206 CPU: 6
EIP is at kmap_atomic_prot+0x7d/0xeb
EAX: c0008d94 EBX: c1ff6240 ECX: 00000163 EDX: 7e000000
ESI: 00000154 EDI: 00000055 EBP: f5cdbf10 ESP: f5cdbef8
DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068
Process kksmd (pid: 343, ti=f5cda000 task=f617b140 task.ti=f5cda000)
Stack:
7fa12163 fffff000 c204efbc f50479e8 9eb7e000 c08a34d0 f5cdbf18 c041f07a
f5cdbf28 c048339c 00000000 f5c271e0 f5cdbf30 c04833bc f5cdbfb0 c0483b0d
f5cdbf50 c0425845 00000000 00000064 00000009 c08a34d0 f5cdbfb0 c06384c1
Call Trace:
[<c041f07a>] ? kmap_atomic+0x13/0x15
[<c048339c>] ? get_pte+0x50/0x63
[<c04833bc>] ? is_present_pte+0xd/0x1f
[<c0483b0d>] ? ksm_scan_start+0x9a/0x7ac
[<c0425845>] ? finish_task_switch+0x29/0xa4
[<c06384c1>] ? schedule+0x6bf/0x719
[<c041b3fc>] ? default_spin_lock_flags+0x8/0xc
[<c043bffa>] ? finish_wait+0x49/0x4e
[<c04845f4>] ? kthread_ksm_scan_thread+0x0/0xdc
[<c048462e>] ? kthread_ksm_scan_thread+0x3a/0xdc
[<c043bf31>] ? autoremove_wake_function+0x0/0x38
[<c043be3e>] ? kthread+0x40/0x66
[<c043bdfe>] ? kthread+0x0/0x66
[<c0404997>] ? kernel_thread_helper+0x7/0x10
Code: 86 00 00 00 64 a1 04 a0 82 c0 6b c0 0d 8d 3c 30 a1 78 b0 77 c0
8d 34 bd 00 00 00 00 89 45 ec a1 0c d0 84 c0 29 f0 83 38 00 74 04 <0f>
0b eb fe c1 ea 1a 8b 04 d5 80 32 8a c0 83 e0 fc 29 c3 c1 fb
EIP: [<c041eff9>] kmap_atomic_prot+0x7d/0xeb SS:ESP 0068:f5cdbef8
Kernel panic - not syncing: Fatal exception
== END of OOPS
diff --git a/mm/ksm.c b/mm/ksm.c
index 707be52..e14448a 100644
--- a/mm/ksm.c
+++ b/mm/ksm.c
@@ -562,6 +562,7 @@ static pte_t *get_pte(struct mm_struct *mm, unsigned long
addr)
goto out;
ptep = pte_offset_map(pmd, addr);
+ pte_unmap(ptep);
out:
return ptep;
}
