On 2022-09-01 10:42, Greg Kroah-Hartman wrote: > On Thu, Sep 01, 2022 at 10:32:55AM -0600, Logan Gunthorpe wrote: >> On 2022-09-01 10:20, Greg Kroah-Hartman wrote: >>> On Thu, Aug 25, 2022 at 09:24:24AM -0600, Logan Gunthorpe wrote: >>>> + /* >>>> + * Removing the alloc attribute from sysfs will call >>>> + * unmap_mapping_range() on the inode, teardown any existing userspace >>>> + * mappings and prevent new ones from being created. >>>> + */ >>>> + sysfs_remove_file_from_group(&pdev->dev.kobj, &p2pmem_alloc_attr.attr, >>>> + p2pmem_group.name); >>> >>> Wait, why are you manually removing the sysfs file here? It's part of >>> the group, if you do this then it is gone for forever, right? Why >>> manually do this the sysfs core should handle this for you if the device >>> is removed. >> >> We have to make sure the mappings are all removed before the cleanup of >> devm_memremap_pages() which will wait for all the pages to be freed. > > Then don't use devm_ functions. Why not just use the manual functions > instead as you know when you want to tear this down. Well we haven't plugged in a remove call into p2pdma, that would be more work and more interfaces touching the PCI code. Note: this code isn't a driver but a set of PCI helpers available to other PCI drivers. Everything that's setup is using the devm interfaces and gets torn down with the same. So I don't really see the benefit of making the change you propose. Logan
