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trace spinlock
- From: Zhiwei Ying <zhiwei dot ying at gmail dot com>
- To: systemtap at sources dot redhat dot com
- Date: Thu, 26 Aug 2010 14:49:59 +0800
- Subject: trace spinlock
Hi,
I am trying to trace the spinlock/spinunlock, but there is something
weired in the output. In some cases, the parm of spinlock becomes "?"
Does anyone know what's reason? And how to fix this?
Thanks,
Zhiwei
tracelock.stp
probe kernel.function("spin_lock").inline
{
??name = execname()
??printf("exec(%s) %s %s\n", name, probefunc(), $$parms)
}
probe kernel.function("spin_unlock").inline
{
??name = execname()
??printf("exec(%s) %s %s\n", name, probefunc(), $$parms)
}
output:
exec(rfs_update_rino) spin_lock lock=0xc0958a00
exec(rfs_update_rino) spin_unlock lock=0xc0958a00
exec(rfs_update_rino) spin_lock lock=?
exec(rfs_update_rino) spin_unlock lock=?