Messages in this thread |  | | | From | "Zhaolei" <> | | Subject | Re: [PATCH] tracing/workqueue: Get rid of searching last executedworklet in probe_worklet_complete() | | Date | Fri, 22 May 2009 08:42:44 +0800 |
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* From: "Oleg Nesterov" <oleg@redhat.com> > On 05/21, Zhaolei wrote: >> We don't need search workqueue's worklet list for worklet which was latest >> executed, instead, we can use a pointer in cpu_workqueue_stats to remember >> which worklet was just executed. > > Minor nit, > >> @@ -192,22 +192,11 @@ probe_worklet_complete(struct task_struct *wq_thread, void *work) >> goto end; >> >> found_wq: >> - list_for_each_entry(wfnode, &node->workfunclist, list) { >> - u64 executed_time; >> + executed_time = trace_clock_global() - node->last_workfunc->start_time; >> + node->last_workfunc->total_time += executed_time; > > Suppose that "enqueue" handler fails to allocate the memory for the new > work_struct. > > This means that the "execute" handler does not record ->last_workfunc. > > In that case probe_worklet_complete() uses the wrong workfunc_stats or > we can even crash if ->last_workfunc == NULL. > > I think _execute() should set ->last_workfunc = NULL first, then serach > for wfnode. _complete() should check ->last_workfunc != NULL and return > if it is NULL. Hello, Oleg
Thanks! You are right, I will send v2 to fix this.
Zhaolei |  |