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x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Rspam-User: X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: EF8D9A0018 X-Stat-Signature: roe8q4wtkpo3a8skb4ifijn36iqwhq8g X-HE-Tag: 1698246436-646056 X-HE-Meta: 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 wpBZ19af R1cQI83UD8exYJX3hAxpbEueiKlfUkeoreOJTkqcxs3nbaNatENn0xlZpSBT5NrcE95jbg0l0ZRt9ZL50egaGqS6qdGqRDJ1N/punio33UtiReT7DwRDmayLBo/Wd5IjcXhUd5bFyOJC6G3o/UfXjco3riq/HSUgwKAen92ZgSdRIiu5J2veVJPiW1eYLCjbwsFgi0hT9yi7aGdalHo+nsun06N2EWE9MO83Znjnxse56iUH45D1xfX0LZhq8Iu7aCdhS+RAaEe23QThfNLtsAtKI4eyrSWKDt54EuYaY1SOhB/4IpgYE+pinAyPWsk/rhU2gyi2q3Q6C/6Sq0ZJFr7CPF9Jo6NQu6fIFZ0dWJTlKkyaOZ7/Qz9yp8g== X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Wed, 25 Oct 2023 10:53:38 -0400 Mathieu Desnoyers wrote: > I don't have an informed opinion on whether the proposed heuristic is a > good idea or not, but it should definitely be implemented as an If you want to get an informed opinion, you can start here: ;-) Thomas's first reply that had me think about this solution: https://lore.kernel.org/lkml/87cyyfxd4k.ffs@tglx/ My reply that started it: https://lore.kernel.org/lkml/20231024103426.4074d319@gandalf.local.home/ > extension to rseq as suggested by Peter. I've even made the whole rseq > ABI extensible to accommodate those additional use-cases. > > In the initial rounds of rseq implementation, I even called rseq "kTLS" > because I expected it to be extended and eventually become an ABI that > contains various per-thread fields which are shared between kernel and > userspace. > > So don't let the specific naming of the rseq system call stop you from > extending it for other purposes when per-thread shared memory between > kernel and userspace is needed. Setting up various per-thread areas like > this on thread creation is not free: it requires additional system calls > on thread creation. It really makes no sense to have more than one. Thanks for the feedback Mathieu. This may indeed be the interface I am looking for. -- Steve