On Wed, 17 Nov 2010 18:52:30 -0500 "Ted Ts'o" <tytso@xxxxxxx> wrote: > On Thu, Nov 18, 2010 at 10:11:43AM +1100, Dave Chinner wrote: > > I don't think ->page_mkwrite can be worked around - we need that to > > be called on the first write fault of any mmap()d page to ensure it > > is set up correctly for writeback. If we don't get write faults > > after the page is mlock()d, then we need the ->page_mkwrite() call > > during the mlock() call. > > OK, so I'm not an mm hacker, so maybe I'm missing something. Could > part of this be fixed by simply sending the write faults for > mlock()'ed pages, so page_mkwrite() gets called when the page is > dirtied. Seems like a real waste to have the file system pre-allocate > all of the blocks for a mlock()'ed region. Why does mlock() have to > result in the write faults getting suppressed when the page is > actually dirtied? Yup, I don't think it would be too bad to take a minor fault each time an mlocked page transitions from clean->dirty. In fact we should already be doing that, after the mlocked page gets written back by kupdate? Hope so! -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom policy in Canada: sign http://dissolvethecrtc.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>