From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:36374) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZWVb1-0000Dp-Nu for qemu-devel@nongnu.org; Mon, 31 Aug 2015 16:22:28 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ZWVax-0004De-Kg for qemu-devel@nongnu.org; Mon, 31 Aug 2015 16:22:27 -0400 Message-ID: <55E4B77C.1080801@redhat.com> Date: Mon, 31 Aug 2015 15:22:20 -0500 From: Wei Huang MIME-Version: 1.0 References: <1440992554-5200-1-git-send-email-hemant@linux.vnet.ibm.com> In-Reply-To: <1440992554-5200-1-git-send-email-hemant@linux.vnet.ibm.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH][RESEND] qemu/kvm_stat: Fix I/O error from kvm_stat List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Hemant Kumar , qemu-devel@nongnu.org Cc: qemu-ppc@nongnu.org, agraf@suse.de 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 > 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 > Signed-off-by: Hemant Kumar > --- > 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