libvirt/examples/systemtap/lock-debug.stp
Martin Kletzander 0e7457e501 Fix common misspellings
Wikipedia's list of common misspellings [1] has a machine-readable
version.  This patch fixes those misspellings mentioned in the list
which don't have multiple right variants (as e.g. "accension", which can
be both "accession" and "ascension"), such misspellings are left
untouched.  The list of changes was manually re-checked for false
positives.

[1] https://en.wikipedia.org/wiki/Wikipedia:Lists_of_common_misspellings/For_machines

Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
2015-03-23 09:01:30 +01:00

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#!/usr/bin/stap --ldd -d /usr/sbin/libvirtd -c libvirtd
#
# Usage with installed libvirt daemon:
# stap --ldd -d /usr/sbin/libvirtd -c libvirtd \
# lock-debug.stp /usr/lib/libvirt.so
#
# If made executable; simple './lock-debug.stp' should work too.
#
# TODOs:
#
# Document usage with uninstalled daemon and libs. Assuming CWD is toplevel
# source git directory, it should be only slight modification to the following:
#
# ./run stap --ldd -c daemon/libvirtd -d daemon/libvirtd
# examples/systemtap/lock-debug.stp src/.libs/libvirt.so
#
# Debug RWLock mechanisms as well.
#
# Author: Martin Kletzander <mkletzan@redhat.com>
global mx_tolock
global mx_locked
function filter()
{
if (pid() != target())
return 1
return 0
}
probe library = process( %( $# > 0 %? @1 %: "/usr/lib/libvirt.so" %) )
{
if (filter()) next
}
probe lock = library.function("virMutexLock")
{
lockname = usymdata($m)
}
probe unlock = library.function("virMutexUnlock")
{
lockname = usymdata($m)
}
probe begin
{
%( $# > 1 %? println("error: Too many parameters"); exit();
%: print("Started, press ^C when the process hangs\n"); %)
}
probe lock.call
{
mx_tolock[lockname, tid()] = sprint_usyms(ubacktrace())
}
probe lock.return
{
if ([lockname, tid()] in mx_tolock) {
mx_locked[lockname, tid()] = mx_tolock[lockname, tid()]
delete mx_tolock[lockname, tid()]
} else {
printf("internal error: lock acquired unwillingly?\n")
}
}
probe unlock.call
{
found = 0
foreach ([lock, tid] in mx_locked) {
if (lock != lockname)
continue
if (tid != tid()) {
printf("Warning: lock released on different thread that locked it.\n")
printf("Lock trace:\n%s\n", mx_locked[lock, tid])
printf("Unlock trace:\n%s\n", sprint_usyms(ubacktrace()))
}
found = tid
break
}
if (found && [lockname, found] in mx_locked)
delete mx_locked[lockname, found]
}
probe end
{
tmp = 0
printf("\n=============\n")
foreach (bt1 = [lock1, tid1] in mx_tolock) {
deadlock = 0
foreach (bt2 = [lock2, tid2] in mx_tolock) {
if (lock1 == lock2) {
if (!tmp++)
printf("The following locks cannot be acquired:\n")
if (!deadlock++)
printf("Lock %s was locked in thread %d with this trace:\n%s\n",
lock1, tid1, bt1)
printf("and is waiting to be locked by thread %d here:\n%s\n",
tid2, bt2)
}
}
if (deadlock)
printf("---\n")
}
if (!tmp)
printf("No deadlocks found, sorry.\n")
}