This bug is awaiting verification that the linux-nvidia/6.8.0-1013.14 kernel in -proposed solves the problem. Please test the kernel and update this bug with the results. If the problem is solved, change the tag 'verification-needed-noble-linux-nvidia' to 'verification-done- noble-linux-nvidia'. If the problem still exists, change the tag 'verification-needed-noble-linux-nvidia' to 'verification-failed-noble- linux-nvidia'.
If verification is not done by 5 working days from today, this fix will be dropped from the source code, and this bug will be closed. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Thank you! ** Tags added: kernel-spammed-noble-linux-nvidia-v2 verification-needed-noble-linux-nvidia -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux-nvidia in Ubuntu. https://bugs.launchpad.net/bugs/2075396 Title: Pull request: mm: fix old/young bit handling in the faulting path of set_pte_range() Status in linux-nvidia package in Ubuntu: Invalid Status in linux-nvidia source package in Noble: Fix Committed Bug description: Commit 3bd786f76de2 ("mm: convert do_set_pte() to set_pte_range()") replaced do_set_pte() with set_pte_range() and that introduced a regression in the following faulting path of non-anonymous vmas which caused the PTE for the faulting address to be marked as old instead of young. handle_pte_fault() do_pte_missing() do_fault() do_read_fault() || do_cow_fault() || do_shared_fault() finish_fault() set_pte_range() The polarity of prefault calculation is incorrect. This leads to prefault being incorrectly set for the faulting address. The following check will incorrectly mark the PTE old rather than young. On some architectures this will cause a double fault to mark it young when the access is retried. if (prefault && arch_wants_old_prefaulted_pte()) entry = pte_mkold(entry); On a subsequent fault on the same address, the faulting path will see a non NULL vmf->pte and instead of reaching the do_pte_missing() path, PTE will then be correctly marked young in handle_pte_fault() itself. Due to this bug, performance degradation in the fault handling path will be observed due to unnecessary double faulting. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux-nvidia/+bug/2075396/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
