[PATCH 2/6] pstore: Add event tracing support
Sai Prakash Ranjan
saiprakash.ranjan at codeaurora.org
Tue Sep 18 10:52:48 PDT 2018
On 9/18/2018 5:04 AM, Steven Rostedt wrote:
> It looks like pstore_event_call() gets called from a trace event. You
> can't call kmalloc() from one. One thing is that kmalloc has
> tracepoints itself. You trace those you just entered an infinite loop.
Ok will remove it in v2. But any alternative way to do this?
>> + event_call = fbuffer->trace_file->event_call;
>> + if (!event_call || !event_call->event.funcs ||
>> + !event_call->event.funcs->trace)
>> + goto fail_event;
>> + event = &fbuffer->trace_file->event_call->event;
>> + spin_lock_irqsave(&psinfo->buf_lock, flags);
>> + trace_seq_init(&iter->seq);
>> + iter->ent = fbuffer->entry;
> I guess what you are doing is needing to translate the raw data into
> ascii output, and need the trace_iterator to do so.
> You are already under a psinfo->buf_lock. Add a dummy iterator to that
> and use it instead.
>> + event_call->event.funcs->trace(iter, 0, event);
> (psinfo->iter, 0 , event);
Sure, will update in v2.
>> + trace_seq_putc(&iter->seq, 0);
>> + if (seq->size > psinfo->bufsize)
>> + seq->size = psinfo->bufsize;
>> + s = &iter->seq;
>> + seq = &s->seq;
>> + record.buf = (char *)(seq->buffer);
>> + record.size = seq->len;
>> + psinfo->write(&record);
>> + spin_unlock_irqrestore(&psinfo->buf_lock, flags);
> You may also need to convert these spin_locks into raw_spin_locks as
> when PREEMPT_RT enters the kernel you don't want them to turn into
> But that can be another patch.
I will change this in v2, but can't we have it in same patch?
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