From: Sasha Levin <sasha.levin@oracle.com>
To: Ingo Molnar <mingo@kernel.org>, Michal Hocko <mhocko@suse.cz>
Cc: Borislav Petkov <bp@alien8.de>,
Linus Torvalds <torvalds@linux-foundation.org>,
LKML <linux-kernel@vger.kernel.org>,
Rusty Russell <rusty@rustcorp.com.au>,
Dave Jones <davej@redhat.com>,
the arch/x86 maintainers <x86@kernel.org>
Subject: Re: Hang on large copy_from_user with PREEMPT_NONE
Date: Tue, 07 Apr 2015 13:00:48 -0400 [thread overview]
Message-ID: <55240D40.6030206@oracle.com> (raw)
In-Reply-To: <20150407143710.GA18777@gmail.com>
On 04/07/2015 10:37 AM, Ingo Molnar wrote:
>
> * Michal Hocko <mhocko@suse.cz> wrote:
>
>> On Tue 07-04-15 13:05:31, Ingo Molnar wrote:
>>>
>>> * Borislav Petkov <bp@alien8.de> wrote:
>>>
>>>> On Tue, Apr 07, 2015 at 11:31:45AM +0200, Ingo Molnar wrote:
>>>>> Would be nice to see the actual kernel .config, as there's a few
>>>>> debug features that can slow things down significantly, such as
>>>>> CONFIG_KMEMCHECK=y or in some cases CONFIG_DEBUG_PAGEALLOC=y.
>>>>
>>>> He sent it here: https://lkml.kernel.org/r/55229D7E.6080309@oracle.com
>>>>
>>>> I'm attaching it again.
>>>
>>> Thanks. Nothing particularly expensive stands out to me at a quick
>>> glance:-/
>>
>> Sasha uses KASAN very often and it is enabled here as well. I guess
>> this might slow things really down.
>
> Indeed, that kind of instrumentation might explain the overhead ...
It locks up quickly without KASan as well.
Thanks,
Sasha
next prev parent reply other threads:[~2015-04-07 17:01 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-04-06 3:59 Hang on large copy_from_user with PREEMPT_NONE Sasha Levin
2015-04-06 11:24 ` Borislav Petkov
2015-04-06 14:51 ` Sasha Levin
2015-04-06 16:52 ` Borislav Petkov
2015-04-06 17:26 ` Linus Torvalds
2015-04-06 19:08 ` Sasha Levin
2015-04-06 19:36 ` Borislav Petkov
2015-04-06 23:45 ` Sasha Levin
2015-04-06 20:42 ` Linus Torvalds
2015-04-07 1:49 ` Rusty Russell
2015-04-07 9:31 ` Ingo Molnar
2015-04-07 10:39 ` Borislav Petkov
2015-04-07 11:05 ` Ingo Molnar
2015-04-07 14:30 ` Michal Hocko
2015-04-07 14:37 ` Ingo Molnar
2015-04-07 17:00 ` Sasha Levin [this message]
2015-04-07 17:33 ` Linus Torvalds
2015-04-07 17:58 ` Dave Jones
[not found] ` <CA+55aFyxCb9aDfh0L4gyvHMSefOFoD7zftRpWbnvf5j9iZVaMw@mail.gmail.com>
2015-04-07 21:09 ` Dave Jones
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