On 29/05/2025 09:23, Baolin Wang wrote: > As we discussed in the previous thread [1], the MADV_COLLAPSE will ignore > the system-wide anon/shmem THP sysfs settings, which means that even though > we have disabled the anon/shmem THP configuration, MADV_COLLAPSE will still > attempt to collapse into a anon/shmem THP. This violates the rule we have > agreed upon: never means never. This patch set will address this issue. This is a drive-by comment from me without having the previous context, but... Surely MADV_COLLAPSE *should* ignore the THP sysfs settings? It's a deliberate user-initiated, synchonous request to use huge pages for a range of memory. There is nothing *transparent* about it, it just happens to be implemented using the same logic that THP uses. I always thought this was a deliberate design decision. Thanks, Ryan > > [1] https://lore.kernel.org/all/1f00fdc3-a3a3-464b-8565-4c1b23d34f8d@xxxxxxxxxxxxxxxxx/ > > Baolin Wang (2): > mm: huge_memory: disallow hugepages if the system-wide THP sysfs > settings are disabled > mm: shmem: disallow hugepages if the system-wide shmem THP sysfs > settings are disabled > > include/linux/huge_mm.h | 23 +++++++++++++++++++---- > mm/huge_memory.c | 2 +- > mm/shmem.c | 12 ++++++------ > 3 files changed, 26 insertions(+), 11 deletions(-) >
