On 10/21/22 10:41, Logan Gunthorpe wrote: > Create a sysfs bin attribute called "allocate" under the existing > "p2pmem" group. The only allowable operation on this file is the mmap() > call. > > When mmap() is called on this attribute, the kernel allocates a chunk of > memory from the genalloc and inserts the pages into the VMA. The > dev_pagemap .page_free callback will indicate when these pages are no > longer used and they will be put back into the genalloc. > > On device unbind, remove the sysfs file before the memremap_pages are > cleaned up. This ensures unmap_mapping_range() is called on the files > inode and no new mappings can be created. > > Signed-off-by: Logan Gunthorpe <logang@xxxxxxxxxxxx> > Acked-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx> > Reviewed-by: Christoph Hellwig <hch@xxxxxx> > Reviewed-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> > --- Reviewed-by: Chaitanya Kulkarni <kch@xxxxxxxxxx> -ck
