Received-SPF: pass (google.com: domain of linux-kernel+bounces-64449-linux.lists.archive=gmail.com@vger.kernel.org designates 147.75.80.249 as permitted sender) client-ip=147.75.80.249;
Message-ID: <6a0f5d8b-9c67-43f6-b25e-2240171265be@redhat.com>
Date: Tue, 13 Feb 2024 23:17:32 +0100
Precedence: bulk
MIME-Version: 1.0
User-Agent: Mozilla Thunderbird
Subject: Re: [PATCH v3 00/35] Memory allocation profiling
Content-Language: en-US
To: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Suren Baghdasaryan <surenb@google.com>, Michal Hocko <mhocko@suse.com>,
 akpm@linux-foundation.org, vbabka@suse.cz, hannes@cmpxchg.org,
 roman.gushchin@linux.dev, mgorman@suse.de, dave@stgolabs.net,
 willy@infradead.org, liam.howlett@oracle.com, corbet@lwn.net,
 void@manifault.com, peterz@infradead.org, juri.lelli@redhat.com,
 catalin.marinas@arm.com, will@kernel.org, arnd@arndb.de, tglx@linutronix.de,
 mingo@redhat.com, dave.hansen@linux.intel.com, x86@kernel.org,
 peterx@redhat.com, axboe@kernel.dk, mcgrof@kernel.org, masahiroy@kernel.org,
 nathan@kernel.org, dennis@kernel.org, tj@kernel.org, muchun.song@linux.dev,
 rppt@kernel.org, paulmck@kernel.org, pasha.tatashin@soleen.com,
 yosryahmed@google.com, yuzhao@google.com, dhowells@redhat.com,
 hughd@google.com, andreyknvl@gmail.com, keescook@chromium.org,
 ndesaulniers@google.com, vvvvvv@google.com, gregkh@linuxfoundation.org,
 ebiggers@google.com, ytcoode@gmail.com, vincent.guittot@linaro.org,
 dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com,
 bristot@redhat.com, vschneid@redhat.com, cl@linux.com, penberg@kernel.org,
 iamjoonsoo.kim@lge.com, 42.hyeyoo@gmail.com, glider@google.com,
 elver@google.com, dvyukov@google.com, shakeelb@google.com,
 songmuchun@bytedance.com, jbaron@akamai.com, rientjes@google.com,
 minchan@google.com, kaleshsingh@google.com, kernel-team@android.com,
 linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org,
 iommu@lists.linux.dev, linux-arch@vger.kernel.org,
 linux-fsdevel@vger.kernel.org, linux-mm@kvack.org,
 linux-modules@vger.kernel.org, kasan-dev@googlegroups.com,
 cgroups@vger.kernel.org
References: <20240212213922.783301-1-surenb@google.com>
 <Zctfa2DvmlTYSfe8@tiehlicka>
 <CAJuCfpEsWfZnpL1vUB2C=cxRi_WxhxyvgGhUg7WdAxLEqy6oSw@mail.gmail.com>
 <9e14adec-2842-458d-8a58-af6a2d18d823@redhat.com>
 <2hphuyx2dnqsj3hnzyifp5yqn2hpgfjuhfu635dzgofr5mst27@4a5dixtcuxyi>
From: David Hildenbrand <david@redhat.com>
Autocrypt: addr=david@redhat.com; keydata=
 xsFNBFXLn5EBEAC+zYvAFJxCBY9Tr1xZgcESmxVNI/0ffzE/ZQOiHJl6mGkmA1R7/uUpiCjJ
 dBrn+lhhOYjjNefFQou6478faXE6o2AhmebqT4KiQoUQFV4R7y1KMEKoSyy8hQaK1umALTdL
 QZLQMzNE74ap+GDK0wnacPQFpcG1AE9RMq3aeErY5tujekBS32jfC/7AnH7I0v1v1TbbK3Gp
 XNeiN4QroO+5qaSr0ID2sz5jtBLRb15RMre27E1ImpaIv2Jw8NJgW0k/D1RyKCwaTsgRdwuK
 Kx/Y91XuSBdz0uOyU/S8kM1+ag0wvsGlpBVxRR/xw/E8M7TEwuCZQArqqTCmkG6HGcXFT0V9
 PXFNNgV5jXMQRwU0O/ztJIQqsE5LsUomE//bLwzj9IVsaQpKDqW6TAPjcdBDPLHvriq7kGjt
 WhVhdl0qEYB8lkBEU7V2Yb+SYhmhpDrti9Fq1EsmhiHSkxJcGREoMK/63r9WLZYI3+4W2rAc
 UucZa4OT27U5ZISjNg3Ev0rxU5UH2/pT4wJCfxwocmqaRr6UYmrtZmND89X0KigoFD/XSeVv
 jwBRNjPAubK9/k5NoRrYqztM9W6sJqrH8+UWZ1Idd/DdmogJh0gNC0+N42Za9yBRURfIdKSb
 B3JfpUqcWwE7vUaYrHG1nw54pLUoPG6sAA7Mehl3nd4pZUALHwARAQABzSREYXZpZCBIaWxk
 ZW5icmFuZCA8ZGF2aWRAcmVkaGF0LmNvbT7CwZgEEwEIAEICGwMGCwkIBwMCBhUIAgkKCwQW
 AgMBAh4BAheAAhkBFiEEG9nKrXNcTDpGDfzKTd4Q9wD/g1oFAl8Ox4kFCRKpKXgACgkQTd4Q
 9wD/g1oHcA//a6Tj7SBNjFNM1iNhWUo1lxAja0lpSodSnB2g4FCZ4R61SBR4l/psBL73xktp
 rDHrx4aSpwkRP6Epu6mLvhlfjmkRG4OynJ5HG1gfv7RJJfnUdUM1z5kdS8JBrOhMJS2c/gPf
 wv1TGRq2XdMPnfY2o0CxRqpcLkx4vBODvJGl2mQyJF/gPepdDfcT8/PY9BJ7FL6Hrq1gnAo4
 3Iv9qV0JiT2wmZciNyYQhmA1V6dyTRiQ4YAc31zOo2IM+xisPzeSHgw3ONY/XhYvfZ9r7W1l
 pNQdc2G+o4Di9NPFHQQhDw3YTRR1opJaTlRDzxYxzU6ZnUUBghxt9cwUWTpfCktkMZiPSDGd
 KgQBjnweV2jw9UOTxjb4LXqDjmSNkjDdQUOU69jGMUXgihvo4zhYcMX8F5gWdRtMR7DzW/YE
 BgVcyxNkMIXoY1aYj6npHYiNQesQlqjU6azjbH70/SXKM5tNRplgW8TNprMDuntdvV9wNkFs
 9TyM02V5aWxFfI42+aivc4KEw69SE9KXwC7FSf5wXzuTot97N9Phj/Z3+jx443jo2NR34XgF
 89cct7wJMjOF7bBefo0fPPZQuIma0Zym71cP61OP/i11ahNye6HGKfxGCOcs5wW9kRQEk8P9
 M/k2wt3mt/fCQnuP/mWutNPt95w9wSsUyATLmtNrwccz63XOwU0EVcufkQEQAOfX3n0g0fZz
 Bgm/S2zF/kxQKCEKP8ID+Vz8sy2GpDvveBq4H2Y34XWsT1zLJdvqPI4af4ZSMxuerWjXbVWb
 T6d4odQIG0fKx4F8NccDqbgHeZRNajXeeJ3R7gAzvWvQNLz4piHrO/B4tf8svmRBL0ZB5P5A
 2uhdwLU3NZuK22zpNn4is87BPWF8HhY0L5fafgDMOqnf4guJVJPYNPhUFzXUbPqOKOkL8ojk
 CXxkOFHAbjstSK5Ca3fKquY3rdX3DNo+EL7FvAiw1mUtS+5GeYE+RMnDCsVFm/C7kY8c2d0G
 NWkB9pJM5+mnIoFNxy7YBcldYATVeOHoY4LyaUWNnAvFYWp08dHWfZo9WCiJMuTfgtH9tc75
 7QanMVdPt6fDK8UUXIBLQ2TWr/sQKE9xtFuEmoQGlE1l6bGaDnnMLcYu+Asp3kDT0w4zYGsx
 5r6XQVRH4+5N6eHZiaeYtFOujp5n+pjBaQK7wUUjDilPQ5QMzIuCL4YjVoylWiBNknvQWBXS
 lQCWmavOT9sttGQXdPCC5ynI+1ymZC1ORZKANLnRAb0NH/UCzcsstw2TAkFnMEbo9Zu9w7Kv
 AxBQXWeXhJI9XQssfrf4Gusdqx8nPEpfOqCtbbwJMATbHyqLt7/oz/5deGuwxgb65pWIzufa
 N7eop7uh+6bezi+rugUI+w6DABEBAAHCwXwEGAEIACYCGwwWIQQb2cqtc1xMOkYN/MpN3hD3
 AP+DWgUCXw7HsgUJEqkpoQAKCRBN3hD3AP+DWrrpD/4qS3dyVRxDcDHIlmguXjC1Q5tZTwNB
 boaBTPHSy/Nksu0eY7x6HfQJ3xajVH32Ms6t1trDQmPx2iP5+7iDsb7OKAb5eOS8h+BEBDeq
 3ecsQDv0fFJOA9ag5O3LLNk+3x3q7e0uo06XMaY7UHS341ozXUUI7wC7iKfoUTv03iO9El5f
 XpNMx/YrIMduZ2+nd9Di7o5+KIwlb2mAB9sTNHdMrXesX8eBL6T9b+MZJk+mZuPxKNVfEQMQ
 a5SxUEADIPQTPNvBewdeI80yeOCrN+Zzwy/Mrx9EPeu59Y5vSJOx/z6OUImD/GhX7Xvkt3kq
 Er5KTrJz3++B6SH9pum9PuoE/k+nntJkNMmQpR4MCBaV/J9gIOPGodDKnjdng+mXliF3Ptu6
 3oxc2RCyGzTlxyMwuc2U5Q7KtUNTdDe8T0uE+9b8BLMVQDDfJjqY0VVqSUwImzTDLX9S4g/8
 kC4HRcclk8hpyhY2jKGluZO0awwTIMgVEzmTyBphDg/Gx7dZU1Xf8HFuE+UZ5UDHDTnwgv7E
 th6RC9+WrhDNspZ9fJjKWRbveQgUFCpe1sa77LAw+XFrKmBHXp9ZVIe90RMe2tRL06BGiRZr
 jPrnvUsUUsjRoRNJjKKA/REq+sAnhkNPPZ/NNMjaZ5b8Tovi8C0tmxiCHaQYqj7G2rgnT0kt
 WNyWQQ==
Organization: Red Hat
In-Reply-To: <2hphuyx2dnqsj3hnzyifp5yqn2hpgfjuhfu635dzgofr5mst27@4a5dixtcuxyi>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 8bit

On 13.02.24 23:09, Kent Overstreet wrote:
> On Tue, Feb 13, 2024 at 11:04:58PM +0100, David Hildenbrand wrote:
>> On 13.02.24 22:58, Suren Baghdasaryan wrote:
>>> On Tue, Feb 13, 2024 at 4:24 AM Michal Hocko <mhocko@suse.com> wrote:
>>>>
>>>> On Mon 12-02-24 13:38:46, Suren Baghdasaryan wrote:
>>>> [...]
>>>>> We're aiming to get this in the next merge window, for 6.9. The feedback
>>>>> we've gotten has been that even out of tree this patchset has already
>>>>> been useful, and there's a significant amount of other work gated on the
>>>>> code tagging functionality included in this patchset [2].
>>>>
>>>> I suspect it will not come as a surprise that I really dislike the
>>>> implementation proposed here. I will not repeat my arguments, I have
>>>> done so on several occasions already.
>>>>
>>>> Anyway, I didn't go as far as to nak it even though I _strongly_ believe
>>>> this debugging feature will add a maintenance overhead for a very long
>>>> time. I can live with all the downsides of the proposed implementation
>>>> _as long as_ there is a wider agreement from the MM community as this is
>>>> where the maintenance cost will be payed. So far I have not seen (m)any
>>>> acks by MM developers so aiming into the next merge window is more than
>>>> little rushed.
>>>
>>> We tried other previously proposed approaches and all have their
>>> downsides without making maintenance much easier. Your position is
>>> understandable and I think it's fair. Let's see if others see more
>>> benefit than cost here.
>>
>> Would it make sense to discuss that at LSF/MM once again, especially
>> covering why proposed alternatives did not work out? LSF/MM is not "too far"
>> away (May).
>>
>> I recall that the last LSF/MM session on this topic was a bit unfortunate
>> (IMHO not as productive as it could have been). Maybe we can finally reach a
>> consensus on this.
> 
> I'd rather not delay for more bikeshedding. Before agreeing to LSF I'd
> need to see a serious proposl - what we had at the last LSF was people
> jumping in with half baked alternative proposals that very much hadn't
> been thought through, and I see no need to repeat that.
> 
> Like I mentioned, there's other work gated on this patchset; if people
> want to hold this up for more discussion they better be putting forth
> something to discuss.

I'm thinking of ways on how to achieve Michal's request: "as long as 
there is a wider agreement from the MM community". If we can achieve 
that without LSF, great! (a bi-weekly MM meeting might also be an option)

-- 
Cheers,

David / dhildenb