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[Qemu-devel] [PATCH] scripts/kvm/kvm_stat: Fix tracefs access checking
From: |
Janosch Frank |
Subject: |
[Qemu-devel] [PATCH] scripts/kvm/kvm_stat: Fix tracefs access checking |
Date: |
Wed, 3 Feb 2016 08:41:31 +0100 |
On kernels build without CONFIG_TRACING kvm_stat will bail out even
when traces are not used. This is not very helpful, especially if the
user can't install a new kernel. Instead, we should warn the user and
fall back to debugfs statistics.
These changes check if trace statistics were selected without kernel
support, warn with a small timeout, set the debugfs statistics option
to True and the tracefs one to False.
Fixes: 7aa4ee5 ('scripts/kvm/kvm_stat: Improve debugfs access checking')
Signed-off-by: Janosch Frank <address@hidden>
---
scripts/kvm/kvm_stat | 20 +++++++++++++++-----
1 file changed, 15 insertions(+), 5 deletions(-)
diff --git a/scripts/kvm/kvm_stat b/scripts/kvm/kvm_stat
index d43e8f3..bab34bb 100755
--- a/scripts/kvm/kvm_stat
+++ b/scripts/kvm/kvm_stat
@@ -22,6 +22,7 @@ import resource
import struct
import re
from collections import defaultdict
+from time import sleep
VMX_EXIT_REASONS = {
'EXCEPTION_NMI': 0,
@@ -778,7 +779,7 @@ def get_providers(options):
return providers
-def check_access():
+def check_access(options):
if not os.path.exists('/sys/kernel/debug'):
sys.stderr.write('Please enable CONFIG_DEBUG_FS in your kernel.')
sys.exit(1)
@@ -790,14 +791,23 @@ def check_access():
"Also ensure, that the kvm modules are loaded.\n")
sys.exit(1)
- if not os.path.exists(PATH_DEBUGFS_TRACING):
- sys.stderr.write("Please make {0} readable by the current user.\n"
+ if not os.path.exists(PATH_DEBUGFS_TRACING) and (options.tracepoints
+ or not options.debugfs):
+ sys.stderr.write("Please enable CONFIG_TRACING in your kernel "
+ "when using the option -t (default).\n"
+ "If it is enabled, make {0} readable by the "
+ "current user.\n"
+ "Falling back to debugfs statistics!\n"
.format(PATH_DEBUGFS_TRACING))
- sys.exit(1)
+ options.debugfs = True
+ options.tracepoints = False
+ sleep(5)
+
+ return options
def main():
- check_access()
options = get_options()
+ options = check_access(options)
providers = get_providers(options)
stats = Stats(providers, fields=options.fields)
--
2.3.0