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From: Oleg Nesterov <oleg@redhat.com>
To: "chunlei.wang" <Chunlei.wang@mediatek.com>
Cc: weiwei.zhang@mediatek.com, wsd_upstream@mediatek.com,
	Peter Zijlstra <peterz@infradead.org>,
	"Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>,
	linux-kernel@vger.kernel.org, linux-mediatek@lists.infradead.org,
	Matthias Brugger <matthias.bgg@gmail.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	Will Deacon <will@kernel.org>
Subject: Re: [PATCH] siganl: ignore other signals when doing coredump
Date: Mon, 3 Aug 2020 21:17:25 +0200	[thread overview]
Message-ID: <20200803191725.GA2078@redhat.com> (raw)
In-Reply-To: <1596185654.11648.1.camel@mbjsdccf07>

On 07/31, chunlei.wang wrote:
>
> Please tell us much more about why you think Linux would benefit from
> this change.  Precisely what operational problems are you seeing with
> the current code?
> =>
>        Sorry for the late reply.
>
>        If coredump is incomplete, R&D can not find root cause through
> coredump.
>  If the issue is seldom, this modification will speed up the process of
> solving the problem.

To be honest, I do not even know what can I say, except that I disagree
with this change. The very idea looks wrong to me.

Granted, SIGKILL can kill the process which does something useful. Say,
dumps a core. So what?

Where does this SIGKILL come from? How often does this happen?

And why do you think the core dumping is special? Say, you try to debug
the buggy application, but a sudden SIGKILL kills the debuggee and you
lose the debugging session. Does this mean that the kernel needs another
patch to protect the process running under gdb from SIGKILL?

I don't think so. Please feel free to resend this patch, but it needs
a very convincing changelog. And please send it to lkml.

Oleg.


_______________________________________________
Linux-mediatek mailing list
Linux-mediatek@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-mediatek

WARNING: multiple messages have this Message-ID (diff)
From: Oleg Nesterov <oleg@redhat.com>
To: "chunlei.wang" <Chunlei.wang@mediatek.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
	Matthias Brugger <matthias.bgg@gmail.com>,
	Peter Zijlstra <peterz@infradead.org>,
	"Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>,
	Will Deacon <will@kernel.org>,
	linux-mediatek@lists.infradead.org, wsd_upstream@mediatek.com,
	weiwei.zhang@mediatek.com, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] siganl: ignore other signals when doing coredump
Date: Mon, 3 Aug 2020 21:17:25 +0200	[thread overview]
Message-ID: <20200803191725.GA2078@redhat.com> (raw)
In-Reply-To: <1596185654.11648.1.camel@mbjsdccf07>

On 07/31, chunlei.wang wrote:
>
> Please tell us much more about why you think Linux would benefit from
> this change.  Precisely what operational problems are you seeing with
> the current code?
> =>
>        Sorry for the late reply.
>
>        If coredump is incomplete, R&D can not find root cause through
> coredump.
>  If the issue is seldom, this modification will speed up the process of
> solving the problem.

To be honest, I do not even know what can I say, except that I disagree
with this change. The very idea looks wrong to me.

Granted, SIGKILL can kill the process which does something useful. Say,
dumps a core. So what?

Where does this SIGKILL come from? How often does this happen?

And why do you think the core dumping is special? Say, you try to debug
the buggy application, but a sudden SIGKILL kills the debuggee and you
lose the debugging session. Does this mean that the kernel needs another
patch to protect the process running under gdb from SIGKILL?

I don't think so. Please feel free to resend this patch, but it needs
a very convincing changelog. And please send it to lkml.

Oleg.


  reply	other threads:[~2020-08-03 19:17 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-07-23  6:52 [PATCH] siganl: ignore other signals when doing coredump chunlei.wang
2020-07-24  0:51 ` Andrew Morton
2020-07-31  8:54   ` chunlei.wang
2020-08-03 19:17     ` Oleg Nesterov [this message]
2020-08-03 19:17       ` Oleg Nesterov

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