From: Wen Yang <wenyang@linux.alibaba.com>
To: Justin Capella <justincapella@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>,
Ingo Molnar <mingo@redhat.com>,
xlpang@linux.alibaba.com, LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v2] ftrace: avoid potential division by zero
Date: Fri, 3 Jan 2020 19:31:49 +0800 [thread overview]
Message-ID: <a2468cc8-cdc1-0a03-6de1-6607bff4d0fa@linux.alibaba.com> (raw)
In-Reply-To: <CAMrEMU8wB4c0TFTSJ4ixQg_gSnW72n_T3ip8ZfZFAk8xWjaKsA@mail.gmail.com>
On 2020/1/3 4:00 下午, Justin Capella wrote:
>> - do_div(stddev, rec->counter * (rec->counter - 1) * 1000);
>>
>> + stddev = div64_ul(stddev,
>> + rec->counter * (rec->counter - 1) * 1000);
>
>
> Is a rec->counter > 1 assertion needed here?
>
Hello, the above lines deal with this situation:
if (rec->counter <= 1)
stddev = 0;
else {
--
Regards,
Wen
prev parent reply other threads:[~2020-01-03 11:31 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-03 3:02 Wen Yang
2020-01-03 8:00 ` Justin Capella
2020-01-03 11:31 ` Wen Yang [this message]
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