Re: [PATCH v1 33/36] mm/gup: drop nth_page() usage in unpin_user_page_range_dirty_lock()
From: David Hildenbrand <hidden>
Date: 2025-08-29 14:41:16
Also in:
dri-devel, intel-gfx, io-uring, kvm, linux-arm-kernel, linux-crypto, linux-ide, linux-iommu, linux-kselftest, linux-mips, linux-mm, linux-mmc, linux-riscv, linux-s390, linux-scsi, lkml, virtualization
On 28.08.25 20:09, Lorenzo Stoakes wrote:
On Thu, Aug 28, 2025 at 12:01:37AM +0200, David Hildenbrand wrote:quoted
There is the concern that unpin_user_page_range_dirty_lock() might do some weird merging of PFN ranges -- either now or in the future -- such that PFN range is contiguous but the page range might not be. Let's sanity-check for that and drop the nth_page() usage. Signed-off-by: David Hildenbrand <redacted>Seems one user uses SG and the other is IOMMU and in each instance you'd expect physical contiguity (maybe Jason G. or somebody else more familiar with these uses can also chime in).
Right, and I added the sanity-check so we can identify and fix any such wrong merging of ranges. Thanks! -- Cheers David / dhildenb