On Tue, 27 Mar 2007 10:28:16 +0200 Miklos Szeredi <[EMAIL PROTECTED]> wrote:
> > > But Peter Staubach says a RH custumer has files written thorugh mmap, > > > which are not being backed up. > > > > Yes, I expect the backup problem is the major real-world hurt arising from > > this bug. > > > > But I expect we could adequately plug that problem at munmap()-time. Or, > > better, do_wp_page(). As I said - half-assed. > > > > It's a question if whether the backup problem is the only thing which is > > hurting > > in the real-world, or if people have other problems. > > > > (In fact, what's wrong with doing it in do_wp_page()? > > It's rather more expensive, than just toggling a bit. It shouldn't be, especially for filesystems which have one-second timestamp granularity. Filesystems which have s_time_gran=1 might hurt a bit, but no more than they will with write(). Actually, no - we'd only update the mctime once per page per writeback period (30 seconds by default) so the load will be small. It'll be more often if the user is doing a lot of pte-cleaning via msync() or fsync(), but then the m/ctime writes will be the least of their problems. I'd have thought there were more substantial problems with something that crude? - 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/
