If users clearly know which file-backed pages to reclaim in system view, they can use this ioctl() to register in advance and reclaim all at once later. To MM and others, I'd like to propose this API in F2FS only, since 1) the use-case is quite limited in Android at the moment. Once it's generall accepted with more use-cases, happy to propose a generic API such as fadvise. Please chime in, if there's any needs. 2) it's file-backed pages which requires to maintain the list of inode objects. I'm not sure this fits in MM tho, also happy to listen to any feedback. Jaegeuk Kim (2): f2fs: register inodes which is able to donate pages f2fs: add a sysfs entry to request donate file-backed pages Documentation/ABI/testing/sysfs-fs-f2fs | 7 +++ fs/f2fs/debug.c | 3 ++ fs/f2fs/f2fs.h | 14 +++++- fs/f2fs/file.c | 65 +++++++++++++++++++++++++ fs/f2fs/inode.c | 14 ++++++ fs/f2fs/shrinker.c | 27 ++++++++++ fs/f2fs/super.c | 1 + fs/f2fs/sysfs.c | 8 +++ include/uapi/linux/f2fs.h | 7 +++ 9 files changed, 145 insertions(+), 1 deletion(-) -- 2.48.0.rc2.279.g1de40edade-goog