On Wed, 2007-03-07 at 16:03 -0700, Eric W. Biederman wrote: > Bill Irwin <[EMAIL PROTECTED]> writes: > > > On Thu, Mar 01, 2007 at 03:46:08PM -0800, Adam Litke wrote: > >> static inline int is_file_hugepages(struct file *file) > >> { > >> - return file->f_op == &hugetlbfs_file_operations; > >> + if (file->f_op == &hugetlbfs_file_operations) > >> + return 1; > >> + if (is_file_shm_hugepages(file)) > >> + return 1; > >> + > >> + return 0; > >> } > > ... > >> +int is_file_shm_hugepages(struct file *file) > >> +{ > >> + int ret = 0; > >> + > >> + if (file->f_op == &shm_file_operations) { > >> + struct shm_file_data *sfd; > >> + sfd = shm_file_data(file); > >> + ret = is_file_hugepages(sfd->file); > >> + } > >> + return ret; > > > > A comment to prepare others for the impending doubletake might be nice. > > Or maybe just open-coding the equality check for &huetlbfs_file_operations > > in is_file_shm_hugepages() if others find it as jarring as I. Please > > extend my ack to any follow-up fiddling with that. > > You did notice we are testing a different struct file? > > > The patch addresses relatively straightforward issues and naturally at > > that. > > The whole concept is recursive so I'm not certain being a recursive check > is that bad but I understand the point. > > I think the right answer is most likely to add an extra file method or > two so we can remove the need for is_file_hugepages. > > There are still 4 calls to is_file_hugepages in ipc/shm.c and > 2 calls in mm/mmap.c not counting the one in is_file_shm_hugepages. > > The special cases make it difficult to properly wrap hugetlbfs files > with another file, which is why we have the weird special case above.
:) Enter my remove-is_file_hugepages() patches (which I posted a few weeks ago). I'll rework them and repost soon. That should help to make all of this cleaner. -- Adam Litke - (agl at us.ibm.com) IBM Linux Technology Center - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/