From: David Hildenbrand <david@redhat.com>
To: Luis Chamberlain <mcgrof@kernel.org>
Cc: linux-modules@vger.kernel.org, linux-kernel@vger.kernel.org,
pmladek@suse.com, petr.pavlu@suse.com, prarit@redhat.com,
christophe.leroy@csgroup.eu, song@kernel.org,
torvalds@linux-foundation.org
Subject: Re: [RFC 00/12] module: avoid userspace pressure on unwanted allocations
Date: Wed, 15 Mar 2023 17:41:53 +0100 [thread overview]
Message-ID: <f18ec4d3-be63-7e86-1951-f3d460acd7a7@redhat.com> (raw)
In-Reply-To: <ZBHuBgUQFbsd6l+J@bombadil.infradead.org>
On 15.03.23 17:10, Luis Chamberlain wrote:
> On Wed, Mar 15, 2023 at 01:24:41PM +0100, David Hildenbrand wrote:
>> On 11.03.23 06:17, Luis Chamberlain wrote:
>>> A long time ago we had some issues with userspace doing stupid stuff.
>>> Well, it turns out even the kernel and do stupid stuff too, as we're
>>> learning with the ACPI modules aliaes and that hammering tons of loads.
>>>
>>> So add a bit of code which gets us a bit more in the defensive about
>>> these situations.
>>>
>>> To experiment, this also adds in-kernel alias support to see if this helps
>>> with some larger systems.
>>>
>>> This is all based on some old code which tried to add defensive
>>> mechanisms the last of which was here and I had dropped the ball:
>>>
>>> https://lore.kernel.org/all/20171208001540.23696-1-mcgrof@kernel.org/
>>>
>>> I've only compile tested this for now. Will need to stress to test
>>> with kmod tests 0008 and 0009 to see if there's any differences.
>>> I'll have to re-test and re-gnuplot stuff there. But early feedback
>>> is appreciated, hence the RFC.
>>>
>>> David Hildenbrand had reported a while ago issues with userspace
>>> doing insane things with allocations bringing a system down to
>>> its knees. This is part of the motivation for this series.
>>
>>
>> I'll try to grab a system where I can reproduce the issue and give your
>> patches a churn.
>
> Great, then please wait for v2 RFC as the first patch was missing an
> obvious mutex grab / release, I already have some memory pressure data
> that shows gains. Hope to post soon.
I expect to have a machine (with a crazy number of CPUs/devices)
available in a couple of days (1-2), so no need to rush.
The original machine I was able to reproduce with is blocked for a
little bit longer; so I hope the alternative I looked up will similarly
trigger the issue easily.
--
Thanks,
David / dhildenb
next prev parent reply other threads:[~2023-03-15 16:47 UTC|newest]
Thread overview: 47+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-03-11 5:17 [RFC 00/12] module: avoid userspace pressure on unwanted allocations Luis Chamberlain
2023-03-11 5:17 ` [RFC 01/12] module: use goto errors on check_modinfo() and layout_and_allocate() Luis Chamberlain
2023-03-11 5:17 ` [RFC 02/12] module: move get_modinfo() helpers all above Luis Chamberlain
2023-03-11 5:17 ` [RFC 03/12] module: rename next_string() to module_next_tag_pair() Luis Chamberlain
2023-03-11 5:17 ` [RFC 04/12] module: add a for_each_modinfo_entry() Luis Chamberlain
2023-03-11 5:17 ` [RFC 05/12] module: add debugging alias parsing support Luis Chamberlain
2023-03-11 5:17 ` [RFC 06/12] module: move early sanity checks into a helper Luis Chamberlain
2023-03-11 5:17 ` [RFC 07/12] module: move check_modinfo() early to early_mod_check() Luis Chamberlain
2023-03-11 5:17 ` [RFC 08/12] module: move finished_loading() Luis Chamberlain
2023-03-11 5:17 ` [RFC 09/12] module: extract patient module check into helper Luis Chamberlain
2023-03-11 5:17 ` [RFC 10/12] module: avoid allocation if module is already present and ready Luis Chamberlain
2023-03-11 5:17 ` [RFC 11/12] module: use list_add_tail_rcu() when adding module Luis Chamberlain
2023-03-11 5:17 ` [RFC 12/12] module: use aliases to find module on find_module_all() Luis Chamberlain
2023-03-11 13:12 ` kernel test robot
2023-03-11 17:06 ` kernel test robot
2023-03-15 14:43 ` Petr Pavlu
2023-03-15 16:12 ` Luis Chamberlain
2023-03-15 12:24 ` [RFC 00/12] module: avoid userspace pressure on unwanted allocations David Hildenbrand
2023-03-15 16:10 ` Luis Chamberlain
2023-03-15 16:41 ` David Hildenbrand [this message]
2023-03-16 23:55 ` Luis Chamberlain
2023-03-16 23:56 ` Luis Chamberlain
2023-03-18 0:11 ` Luis Chamberlain
2023-03-20 9:38 ` David Hildenbrand
2023-03-20 19:40 ` David Hildenbrand
2023-03-20 21:09 ` Luis Chamberlain
2023-03-20 21:15 ` David Hildenbrand
2023-03-20 21:23 ` Luis Chamberlain
2023-03-20 21:27 ` Luis Chamberlain
2023-03-21 19:32 ` David Hildenbrand
2023-03-24 9:27 ` David Hildenbrand
2023-03-24 17:54 ` Luis Chamberlain
2023-03-24 19:11 ` Linus Torvalds
2023-03-24 19:59 ` Luis Chamberlain
2023-03-24 20:28 ` Linus Torvalds
2023-03-24 21:14 ` Luis Chamberlain
2023-03-24 23:27 ` Luis Chamberlain
2023-03-24 23:41 ` Linus Torvalds
2023-03-28 3:44 ` David Hildenbrand
2023-03-28 6:16 ` Luis Chamberlain
2023-03-28 21:02 ` David Hildenbrand
2023-03-29 5:31 ` Luis Chamberlain
2023-03-30 4:42 ` David Hildenbrand
2023-03-21 15:11 ` David Hildenbrand
2023-03-21 16:52 ` Luis Chamberlain
2023-03-21 17:01 ` David Hildenbrand
2023-03-20 9:37 ` David Hildenbrand
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