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From:   Thomas Gleixner <tglx@linutronix.de>
To:     Walter Wu <walter-zh.wu@mediatek.com>
Cc:     Andrew Morton <akpm@linux-foundation.org>,
        John Stultz <john.stultz@linaro.org>,
        Stephen Boyd <sboyd@kernel.org>,
        Marco Elver <elver@google.com>,
        Andrey Ryabinin <aryabinin@virtuozzo.com>,
        Alexander Potapenko <glider@google.com>,
        Dmitry Vyukov <dvyukov@google.com>,
        Andrey Konovalov <andreyknvl@google.com>,
        Matthias Brugger <matthias.bgg@gmail.com>,
        kasan-dev@googlegroups.com, linux-mm@kvack.org,
        linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        wsd_upstream <wsd_upstream@mediatek.com>,
        linux-mediatek@lists.infradead.org
Subject: Re: [PATCH v4 1/6] timer: kasan: record timer stack
In-Reply-To: <1601025346.2255.2.camel@mtksdccf07>
References: <20200924040335.30934-1-walter-zh.wu@mediatek.com> <87h7rm97js.fsf@nanos.tec.linutronix.de> <1601018323.28162.4.camel@mtksdccf07> <87lfgyutf8.fsf@nanos.tec.linutronix.de> <1601025346.2255.2.camel@mtksdccf07>
Date:   Sat, 26 Sep 2020 00:59:35 +0200
Message-ID: <87wo0htqco.fsf@nanos.tec.linutronix.de>
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On Fri, Sep 25 2020 at 17:15, Walter Wu wrote:
> On Fri, 2020-09-25 at 10:55 +0200, Thomas Gleixner wrote:
>> > We don't want to replace DEBUG_OBJECTS_TIMERS with this patches, only
>> > hope to use low overhead(compare with DEBUG_OBJECTS_TIMERS) to debug
>> 
>> KASAN has lower overhead than DEBUG_OBJECTS_TIMERS? Maybe in a different
>> universe.
>> 
> I mean KASAN + our patch vs KASAN + DEBUG_OBJECTS_TIMERS. The front one
> have the information to the original caller and help to debug. It is
> smaller overhead than the one behind.

For ONE specific problem related to timers and you have still not shown
a single useful debug output where this information helps to debug
anything.

> I agree your saying, so that I need to find out a use case to explain to
> you.

Indeed.

Thanks,

        tglx