From: Dave Hansen <dave.hansen@intel.com>
To: Alexander Duyck <alexander.duyck@gmail.com>, mhocko@kernel.org
Cc: linux-mm <linux-mm@kvack.org>,
LKML <linux-kernel@vger.kernel.org>,
linux-nvdimm@lists.01.org, pavel.tatashin@microsoft.com,
dave.jiang@intel.com, Ingo Molnar <mingo@kernel.org>,
jglisse@redhat.com, Andrew Morton <akpm@linux-foundation.org>,
logang@deltatee.com, dan.j.williams@intel.com,
"Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Subject: Re: [PATCH 1/4] mm: Provide kernel parameter to allow disabling page init poisoning
Date: Wed, 12 Sep 2018 08:23:58 -0700 [thread overview]
Message-ID: <841e8101-40db-9ff2-f688-5f175d91fc31@intel.com> (raw)
In-Reply-To: <CAKgT0UdvhV7U5Zniq=KskXz2QsRP8C7ctr5=ZtJwYAVpBT-RHw@mail.gmail.com>
On 09/12/2018 07:49 AM, Alexander Duyck wrote:
>>> + page_init_poison= [KNL] Boot-time parameter changing the
>>> + state of poisoning of page structures during early
>>> + boot. Used to verify page metadata is not accessed
>>> + prior to initialization. Available with
>>> + CONFIG_DEBUG_VM=y.
>>> + off: turn off poisoning
>>> + on: turn on poisoning (default)
>>> +
>> what about the following wording or something along those lines
>>
>> Boot-time parameter to control struct page poisoning which is a
>> debugging feature to catch unitialized struct page access. This option
>> is available only for CONFIG_DEBUG_VM=y and it affects boot time
>> (especially on large systems). If there are no poisoning bugs reported
>> on the particular system and workload it should be safe to disable it to
>> speed up the boot time.
> That works for me. I will update it for the next release.
FWIW, I rather liked Dan's idea of wrapping this under
vm_debug=<something>. We've got a zoo of boot options and it's really
hard to _remember_ what does what. For this case, we're creating one
that's only available under a specific debug option and I think it makes
total sense to name the boot option accordingly.
For now, I think it makes total sense to do vm_debug=all/off. If, in
the future, we get more options, we can do things like slab does and do
vm_debug=P (for Page poison) for this feature specifically.
vm_debug = [KNL] Available with CONFIG_DEBUG_VM=y.
May slow down boot speed, especially on larger-
memory systems when enabled.
off: turn off all runtime VM debug features
all: turn on all debug features (default)
next prev parent reply other threads:[~2018-09-12 15:25 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-09-10 23:43 [PATCH 0/4] Address issues slowing persistent memory initialization Alexander Duyck
2018-09-10 23:43 ` [PATCH 1/4] mm: Provide kernel parameter to allow disabling page init poisoning Alexander Duyck
2018-09-11 0:35 ` Alexander Duyck
2018-09-11 16:50 ` Dan Williams
2018-09-11 20:01 ` Alexander Duyck
2018-09-11 20:24 ` Dan Williams
2018-09-12 13:24 ` Pasha Tatashin
2018-09-12 14:10 ` Michal Hocko
2018-09-12 14:49 ` Alexander Duyck
2018-09-12 15:23 ` Dave Hansen [this message]
2018-09-12 16:36 ` Alexander Duyck
2018-09-12 16:43 ` Dave Hansen
2018-09-10 23:43 ` [PATCH 2/4] mm: Create non-atomic version of SetPageReserved for init use Alexander Duyck
2018-09-12 13:28 ` Pasha Tatashin
2018-09-10 23:43 ` [PATCH 3/4] mm: Defer ZONE_DEVICE page initialization to the point where we init pgmap Alexander Duyck
2018-09-11 7:49 ` kbuild test robot
2018-09-11 7:54 ` kbuild test robot
2018-09-11 22:35 ` Dan Williams
2018-09-12 0:51 ` Alexander Duyck
2018-09-12 0:59 ` Dan Williams
2018-09-12 13:59 ` Pasha Tatashin
2018-09-12 15:48 ` Alexander Duyck
2018-09-12 15:54 ` Pasha Tatashin
2018-09-12 16:44 ` Alexander Duyck
2018-09-12 16:50 ` Dan Williams
2018-09-12 17:46 ` Pasha Tatashin
2018-09-12 19:11 ` Dan Williams
2018-09-10 23:44 ` [PATCH 4/4] nvdimm: Trigger the device probe on a cpu local to the device Alexander Duyck
2018-09-11 0:37 ` Alexander Duyck
2018-09-12 5:48 ` Dan Williams
2018-09-12 13:44 ` Pasha Tatashin
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