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Re: [PATCH v2] [RFC] tracepoint: Add signal coredump tracepoint
- From: Masami Hiramatsu <mhiramat at redhat dot com>
- To: Ingo Molnar <mingo at elte dot hu>
- Cc: Andrew Morton <akpm at linux-foundation dot org>, lkml <linux-kernel at vger dot kernel dot org>, systemtap <systemtap at sources dot redhat dot com>, DLE <dle-develop at lists dot sourceforge dot net>, Oleg Nesterov <oleg at redhat dot com>, Roland McGrath <roland at redhat dot com>, Jason Baron <jbaron at redhat dot com>, KOSAKI Motohiro <kosaki dot motohiro at jp dot fujitsu dot com>
- Date: Thu, 03 Dec 2009 06:32:29 -0500
- Subject: Re: [PATCH v2] [RFC] tracepoint: Add signal coredump tracepoint
- References: <4B128ECF.9020906@redhat.com> <20091202204637.25408.41195.stgit@dhcp-100-2-132.bos.redhat.com> <20091203103935.GA7628@elte.hu>
Ingo Molnar wrote:
>
> * Masami Hiramatsu <mhiramat@redhat.com> wrote:
>
>> Add signal coredump tracepoint which shows signal number, mm->flags,
>> limits, pointer to file structure and core file name.
>
> Why is the kernel pointer to the file structure logged? User-space has
> no use for it and the analysis value is low.
Ah, if open() or opening pipe fails, it becomes 0 or -ERRNO,
so we can check if there is an error.
Perhaps, we can do below in trace_printk for trace users.
"open %s", (!file || IS_ERR((void *)file)) ? "failed" : "succeeded"
Thank you,
--
Masami Hiramatsu
Software Engineer
Hitachi Computer Products (America), Inc.
Software Solutions Division
e-mail: mhiramat@redhat.com