Nick Piggin <nickpiggin@xxxxxxxxxxxx> wrote: > 1) PG_mappedtodisk is basically PG_owner_priv_2. Please alias that and > use it? Then at least we're down to 1 extra flag. > 2) Why do you need another PG_private? PG_private for pagecache means > that it should call into the filesystem when it needs to handle fs data > attached to the page, right? So PG_private_2 doesn't really make sense > in that respect. Won't that either break fs/buffer.c and fs/mpage.c or preclude the use of FS-Cache with block-based filesystems that use the standard buffer wangling routines? As I've previously stated, I want to be able to make ISO9660 use FS-Cache. That rules out use of PG_mappedtodisk and PG_private for anything FS-Cache related. We can actually reclaim PG_private, I think. There are patches to do that. At the very least, we can probably reclaim the std buffering code's use of it. If anything, avoiding the need for PG_fscache_write is probably easier - just more memory intensive and slower. I could build a second radix tree for each inode that kept track of which pages from that inode FS-Cache knows about, and use the status bits in that node to keep track of what pages are being written out to the cache. We still need a way of triggering the page invalidation callbacks for in-use pages, however. PG_private, as I've said, is not currently a viable option. David -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
