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Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Shuah Khan , John Hubbard , Kalesh Singh , Anshuman Khandual , Park Tae-sun , linux-mm@kvack.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org References: <20260924050009.19974-1-sarthak.sharma@arm.com> Content-Language: en-US From: Sarthak Sharma In-Reply-To: <20260924050009.19974-1-sarthak.sharma@arm.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Rspamd-Server: rspam06 X-Stat-Signature: g4bib44sonw5dmy968hgbobiqo3wazin X-Rspam-User: X-Rspamd-Queue-Id: 1A29220008 X-HE-Tag: 1790661275-254726 X-HE-Meta: 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 xn7pHFzG Q9BU81YNzr66IgkfRtXTAVuw0sWXh49G1I8L4TEUmDc6p2Dkty5J9gm12zDVbp5T0bbFHvN6yvq3N304f4wFs4baJzWjSwoxhO/2Xw7fb+yoIp8KeOqIBSJ5GEGobLnyirjBtSNxehow5z4WugIEBM0Sw331n8aCXDSfK/gdVLQSjZNS/qSUlP/2jG70ijpI5DioS/TUH2sXraU74uaWhA+w4o88dzACydwKMgPSgx11TOpbO3SwWd6KCalY2uj0dedtCCoT05beKbnBk7JOOA6RKEx+FyVZ8uETIHI5G4hsiOWMjdB6I+bNZqw6vu++blmp0YLfgZh8ZhyTuvEw5Bh4gSDrZoHpbz+xP0p8jTMFbQyzWs+XXfSKV1YgqcezkhXMa84T/k2LbHRX3qv/9EMQTsahjBFSTchfZ+HIcRiwp13s= Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 9/24/26 10:30 AM, Sarthak Sharma wrote: > This series fixes several correctness issues in mremap_test and > simplifies and strengthens its data validation. > > Patch 1 converts the mremap_test to use kselftest helpers, removes > manual tracking of failed tests and corrects some spelling errors. > > Patches 2 to 5 fix userfaultfd skipping, unexpected mremap success > handling, multi-VMA data validation and failure reporting when data > corruption is detected. > > Patch 6 removes the randomization and uses a simple pattern based approach. > > Patch 7 removes perf tests and timing infrastructure. > > Patch 8 removes validation threshold and always validates complete mappings. > > Patch 9 strengthens the multi VMA validation by also checking the > mapping state of holes after remapping. Hello everyone! Just wanted to check if someone has had a chance to look at the series. Also, Sashiko has a concern [1], and I had the same while posting the series. I hope I can get some opinion from the community. Currently, for PUD remap tests, we allocate a source mapping of 2GB. We only fault in the first threshold_mb amount of memory, remap the whole region, and validate the already faulted threshold_mb amount of memory, which is, by default, equal to 4MB and can be changed by the user by supplying a command line option. Since we plan to remove all command line options from teh selftests, I removed threshold_mb altogether, following some discussion on the list [2]. This would now cause a 2GB source mapping, and its contents copied from another 2GB buffer. This causes the process to have a 4GB RSS. Sashiko says that this can cause OOM killing in small CI machines. Would it be okay to keep a 4GB RSS in this case, or should we find some other way of validating a part of the whole range instead? [1] https://sashiko.dev/#/patchset/20260924050009.19974-1-sarthak.sharma%40arm.com [2] https://lore.kernel.org/all/2e34b619-085f-4a9c-bb41-bc024fd40dd7@kernel.org/