* [Qemu-devel] [PATCH][RESEND] qemu/kvm_stat: Fix I/O error from kvm_stat
@ 2015-08-31 3:42 Hemant Kumar
2015-08-31 20:22 ` Wei Huang
0 siblings, 1 reply; 3+ messages in thread
From: Hemant Kumar @ 2015-08-31 3:42 UTC (permalink / raw)
To: qemu-devel; +Cc: wei, Hemant Kumar, qemu-ppc, agraf
Running kvm_stat on a powerpc macine where the kernel is compiled with
KVM_BOOK3S_HV_EXIT_TIMING config option, generates the following error :
# kvm_stat
Traceback (most recent call last):
File "/usr/bin/kvm_stat", line 644, in <module>
curses.wrapper(tui, stats)
File "/usr/lib64/python2.7/curses/wrapper.py", line 43, in wrapper
return func(stdscr, *args, **kwds)
File "/usr/bin/kvm_stat", line 550, in tui
refresh(sleeptime)
File "/usr/bin/kvm_stat", line 526, in refresh
s = stats.get()
File "/usr/bin/kvm_stat", line 486, in get
new = d.read()
File "/usr/bin/kvm_stat", line 29, in read
return dict([(key, val(key)) for key in self._fields])
File "/usr/bin/kvm_stat", line 28, in val
return int(file(self.base + '/' + key).read())
IOError: [Errno 21] Is a directory: '/sys/kernel/debug/kvm/vm12840'
The error says that its trying to read the contents of a directory as if
it were a file. The kernel here creates directories inside
"/sys/kernel/debug/kvm/" for the individual VMs running on the
machine. These directories contain timing information (for rm_entry,
rm_intr, rm_exit, guest, cede) related to each vcpu of each VM. All of
this is enabled with KVM_BOOK3S_HV_EXIT_TIMING config option for the
kernel.
kvm_stat script isn't supposed to parse/read these directories and isn't
even expecting any directories inside "/sys/kernel/debug/kvm/". This
patch fixes the problem by avoiding lookup for these directories.
Reported-by: Krishnaja Balachandran <kribalac@in.ibm.com>
Signed-off-by: Hemant Kumar <hemant@linux.vnet.ibm.com>
---
scripts/kvm/kvm_stat | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/scripts/kvm/kvm_stat b/scripts/kvm/kvm_stat
index 7e5d256..1da7a53 100755
--- a/scripts/kvm/kvm_stat
+++ b/scripts/kvm/kvm_stat
@@ -18,7 +18,11 @@ from ctypes import *
class DebugfsProvider(object):
def __init__(self):
self.base = '/sys/kernel/debug/kvm'
- self._fields = os.listdir(self.base)
+ files = os.listdir(self.base)
+ self._fields = []
+ for f in files:
+ if os.path.isfile(self.base + '/' + f):
+ self._fields.append(f)
def fields(self):
return self._fields
def select(self, fields):
--
1.9.3
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [Qemu-devel] [PATCH][RESEND] qemu/kvm_stat: Fix I/O error from kvm_stat
2015-08-31 3:42 [Qemu-devel] [PATCH][RESEND] qemu/kvm_stat: Fix I/O error from kvm_stat Hemant Kumar
@ 2015-08-31 20:22 ` Wei Huang
2015-09-01 6:50 ` Hemant Kumar
0 siblings, 1 reply; 3+ messages in thread
From: Wei Huang @ 2015-08-31 20:22 UTC (permalink / raw)
To: Hemant Kumar, qemu-devel; +Cc: qemu-ppc, agraf
On 08/30/2015 10:42 PM, Hemant Kumar wrote:
> Running kvm_stat on a powerpc macine where the kernel is compiled with
> KVM_BOOK3S_HV_EXIT_TIMING config option, generates the following error :
>
> # kvm_stat
>
> Traceback (most recent call last):
> File "/usr/bin/kvm_stat", line 644, in <module>
> curses.wrapper(tui, stats)
> File "/usr/lib64/python2.7/curses/wrapper.py", line 43, in wrapper
> return func(stdscr, *args, **kwds)
> File "/usr/bin/kvm_stat", line 550, in tui
> refresh(sleeptime)
> File "/usr/bin/kvm_stat", line 526, in refresh
> s = stats.get()
> File "/usr/bin/kvm_stat", line 486, in get
> new = d.read()
> File "/usr/bin/kvm_stat", line 29, in read
> return dict([(key, val(key)) for key in self._fields])
> File "/usr/bin/kvm_stat", line 28, in val
> return int(file(self.base + '/' + key).read())
> IOError: [Errno 21] Is a directory: '/sys/kernel/debug/kvm/vm12840'
>
> The error says that its trying to read the contents of a directory as if
> it were a file. The kernel here creates directories inside
> "/sys/kernel/debug/kvm/" for the individual VMs running on the
> machine. These directories contain timing information (for rm_entry,
> rm_intr, rm_exit, guest, cede) related to each vcpu of each VM. All of
> this is enabled with KVM_BOOK3S_HV_EXIT_TIMING config option for the
> kernel.
A suggestion: would it be useful to display these statistics in
perf_stat? I understand that these counters are per-vm-based; but they
might provide useful insights to end-users.
>
> kvm_stat script isn't supposed to parse/read these directories and isn't
> even expecting any directories inside "/sys/kernel/debug/kvm/". This
> patch fixes the problem by avoiding lookup for these directories.
>
> Reported-by: Krishnaja Balachandran <kribalac@in.ibm.com>
> Signed-off-by: Hemant Kumar <hemant@linux.vnet.ibm.com>
> ---
> scripts/kvm/kvm_stat | 6 +++++-
> 1 file changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/scripts/kvm/kvm_stat b/scripts/kvm/kvm_stat
> index 7e5d256..1da7a53 100755
> --- a/scripts/kvm/kvm_stat
> +++ b/scripts/kvm/kvm_stat
> @@ -18,7 +18,11 @@ from ctypes import *
> class DebugfsProvider(object):
> def __init__(self):
> self.base = '/sys/kernel/debug/kvm'
> - self._fields = os.listdir(self.base)
> + files = os.listdir(self.base)
> + self._fields = []
> + for f in files:
> + if os.path.isfile(self.base + '/' + f):
> + self._fields.append(f)
> def fields(self):
> return self._fields
> def select(self, fields):
>
I tested this patch on x86 box and didn't see any problem. So:
Reviewed-by: Wei Huang <wei@redhat.com>
-Wei
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [Qemu-devel] [PATCH][RESEND] qemu/kvm_stat: Fix I/O error from kvm_stat
2015-08-31 20:22 ` Wei Huang
@ 2015-09-01 6:50 ` Hemant Kumar
0 siblings, 0 replies; 3+ messages in thread
From: Hemant Kumar @ 2015-09-01 6:50 UTC (permalink / raw)
To: Wei Huang, qemu-devel; +Cc: qemu-ppc, agraf
Hi Wei,
Thanks for the review.
On 09/01/2015 01:52 AM, Wei Huang wrote:
> On 08/30/2015 10:42 PM, Hemant Kumar wrote:
>> Running kvm_stat on a powerpc macine where the kernel is compiled with
>> KVM_BOOK3S_HV_EXIT_TIMING config option, generates the following error :
>>
>> # kvm_stat
>>
>> Traceback (most recent call last):
>> File "/usr/bin/kvm_stat", line 644, in <module>
>> curses.wrapper(tui, stats)
>> File "/usr/lib64/python2.7/curses/wrapper.py", line 43, in wrapper
>> return func(stdscr, *args, **kwds)
>> File "/usr/bin/kvm_stat", line 550, in tui
>> refresh(sleeptime)
>> File "/usr/bin/kvm_stat", line 526, in refresh
>> s = stats.get()
>> File "/usr/bin/kvm_stat", line 486, in get
>> new = d.read()
>> File "/usr/bin/kvm_stat", line 29, in read
>> return dict([(key, val(key)) for key in self._fields])
>> File "/usr/bin/kvm_stat", line 28, in val
>> return int(file(self.base + '/' + key).read())
>> IOError: [Errno 21] Is a directory: '/sys/kernel/debug/kvm/vm12840'
>>
>> The error says that its trying to read the contents of a directory as if
>> it were a file. The kernel here creates directories inside
>> "/sys/kernel/debug/kvm/" for the individual VMs running on the
>> machine. These directories contain timing information (for rm_entry,
>> rm_intr, rm_exit, guest, cede) related to each vcpu of each VM. All of
>> this is enabled with KVM_BOOK3S_HV_EXIT_TIMING config option for the
>> kernel.
> A suggestion: would it be useful to display these statistics in
> perf_stat? I understand that these counters are per-vm-based; but they
> might provide useful insights to end-users.
It would be definitely useful to display these statistics, but since this
script doesn't work on powerpc with the config option enabled, this
patch should work as a fix for now.
We can work on enhancing kvm_stat to display these per vm statistics.
>> kvm_stat script isn't supposed to parse/read these directories and isn't
>> even expecting any directories inside "/sys/kernel/debug/kvm/". This
>> patch fixes the problem by avoiding lookup for these directories.
>>
>> Reported-by: Krishnaja Balachandran <kribalac@in.ibm.com>
>> Signed-off-by: Hemant Kumar <hemant@linux.vnet.ibm.com>
>> ---
>> scripts/kvm/kvm_stat | 6 +++++-
>> 1 file changed, 5 insertions(+), 1 deletion(-)
>>
>> diff --git a/scripts/kvm/kvm_stat b/scripts/kvm/kvm_stat
>> index 7e5d256..1da7a53 100755
>> --- a/scripts/kvm/kvm_stat
>> +++ b/scripts/kvm/kvm_stat
>> @@ -18,7 +18,11 @@ from ctypes import *
>> class DebugfsProvider(object):
>> def __init__(self):
>> self.base = '/sys/kernel/debug/kvm'
>> - self._fields = os.listdir(self.base)
>> + files = os.listdir(self.base)
>> + self._fields = []
>> + for f in files:
>> + if os.path.isfile(self.base + '/' + f):
>> + self._fields.append(f)
>> def fields(self):
>> return self._fields
>> def select(self, fields):
>>
> I tested this patch on x86 box and didn't see any problem. So:
>
> Reviewed-by: Wei Huang <wei@redhat.com>
Thanks!
--
Hemant Kumar
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2015-09-01 6:50 UTC | newest]
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2015-08-31 3:42 [Qemu-devel] [PATCH][RESEND] qemu/kvm_stat: Fix I/O error from kvm_stat Hemant Kumar
2015-08-31 20:22 ` Wei Huang
2015-09-01 6:50 ` Hemant Kumar
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