# Re: \[PATCH v3 5/7\] selftests: add memfd/sealing page-pinning tests - From: David Herrmann \ - Date: 2014-07-19 16:32:55 - List: linux-api - Page: https://ratatoskr.run/linux-api/2014/07/86273 - Thread: https://ratatoskr.run/linux-mm/2014/06/85586/t.md ```text Hi On Wed, Jul 16, 2014 at 12:08 PM, Hugh Dickins [ref] wrote: > On Fri, 13 Jun 2014, David Herrmann wrote: > >> Setting SEAL_WRITE is not possible if there're pending GUP users. This >> commit adds selftests for memfd+sealing that use FUSE to create pending >> page-references. FUSE is very helpful here in that it allows us to delay >> direct-IO operations for an arbitrary amount of time. This way, we can >> force the kernel to pin pages and then run our normal selftests. >> >> Signed-off-by: David Herrmann > > I had a number of problems in getting this working (on openSUSE 13.1): > rpm told me I had fuse installed, yet I had to download and install > the tarball to get header files needed; then "make fuse_mnt" told me > to add -D_FILE_OFFSET_BITS=64 to the compile flags; after which I > got "undefined reference to `fuse_main_real'"; but then I tried > "make run_fuse" as root, and it seemed to sort these issues out > for itself, aside from "./run_fuse_test.sh: Permission denied" - > which was within my bounds of comprehension unlike the rest! > > No complaint, thanks for providing the test (though I didn't check > the source to convince myself that "DONE" has done what's claimed): > some rainy day someone can get the Makefile working more smoothly, > no need to delay the patchset for this. _FILE_OFFSET_BITS=64 makes sense. I added it. The "undefined ref" thing doesn't make sense to me and I cannot reproduce it. I will see what I can do. The "Permission denied" obviously just requires access to /dev/fuse, as you figured out yourself. Thanks David -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org ```