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Howlett" , David Hildenbrand , Lorenzo Stoakes , Shakeel Butt , Vlastimil Babka , kernel-team@meta.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH 0/9] mm/madvise: batch tlb flushes for MADV_DONTNEED and MADV_FREE Message-Id: <20250310153921.47d390c637105e3ad6fc49c0@linux-foundation.org> In-Reply-To: <20250310172318.653630-1-sj@kernel.org> References: <20250310172318.653630-1-sj@kernel.org> X-Mailer: Sylpheed 3.7.0 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Rspamd-Queue-Id: E03FA18000C X-Stat-Signature: bxcikqk64b4wrpocpiz8syed9tgwo53q X-Rspamd-Server: rspam02 X-Rspam-User: X-HE-Tag: 1741646363-394621 X-HE-Meta: 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 SfNOv3Hn LuDjpsX2A3ygAApf84zyZ0Wr4hz0KSerZKZ2X1ei96jRlK92iS6jIPEgaEG5U2K/CRI/xHfIw2bwtfK0/HAsuIJKswgqECieYKrRFCJWbO8zEUcmyfgelqB/NPfnWhUaYbmv4/3kKhU67sCC8i+Nn11UUt4HQQzlCXyjzyjJMvDHL2SbkyeT8wQslWFnh0rQgsh59T5kHxWJXINpsSs0MPzNMXQmGLtWyQje1lYVKqnHZLPHTEm9WAs4Gu8fBZ4hSPLuD55488bLjgxU/ro0dMM0yu7IjwaJ6eYSbv9FWfYeI9oSrEujYrN9csqdvIrGIHCNt 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 Mon, 10 Mar 2025 10:23:09 -0700 SeongJae Park wrote: > It is unclear if such use case > is common and the inefficiency is significant. Well, we could conduct a survey, Can you add some logging to detect when userspace performs such an madvise() call, then run that kernel on some "typical" machines which are running "typical" workloads? That should give us a feeling for how often userspace does this, and hence will help us understand the usefulness of this patchset.