On Wed, 2006-12-20 at 14:25 -0800, Linus Torvalds wrote: > > On Wed, 20 Dec 2006, Dave Kleikamp wrote: > > > > This patch removes some questionable code that attempted to make a > > no-longer-used page easier to reclaim. > > If so, "cancel_dirty_page()" may actually be the right thing to use, but > only if you can guarantee that the page isn't mapped anywhere (and from > the name of the function I guess it's not something that you'll ever map?)
That's correct. It can't be mapped. It's a private mapping only used for metadata. I'm really not sure the code in question is having the intended effect. Maybe one of the gurus on cc: can take a look at the code and tell me if it's worth keeping. I apologize in advance if it makes anyone lose their lunch. > So the JFS code _looks_ like you could just replace the > > clear_page_dirty(page); > > with > > cancel_dirty_page(page, PAGE_CACHE_SIZE); > > (where that second parameter is just used for statistics - it updates the > "cancelled IO" byte-counts if CONFIG_TASK_IO_ACCOUNTING is set - so the > number doesn't really matter, you could make it zero if you never want the > thing to show up in the IO accounting). I'm not sure whether zero or PAGE_CACHE_SIZE would be better. The situation is where some page of metadata is no longer used, say shrinking a directory tree or truncating a file and throwing out the extent tree. Thanks, Shaggy -- David Kleikamp 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/
