Andrew, I have a series aimed at 2.6.41 to remove mm/shmem.c's peculiar radix tree of swap entries, using slots in the file's standard radix_tree instead - prompted in part by https://lkml.org/lkml/2011/1/22/110 There's a patch to give shmem its own truncation loop, handling pages and swap entries in the same pass. For that I want to start from a copy of truncate_inode_page_range(), but notice some discrepancies between the different loops in mm/truncate.c, so want to standardize them first before copying. The advancement of index is hard to follow: we rely upon page->index of an unlocked page persisting, yet we're ashamed of doing so, sometimes reading it again once locked. invalidate_mapping_pages() apologizes for this, but I think we should now just document that page->index is not modified until the page is freed. invalidate_inode_pages2_range() has two sophistications not seen elsewhere, which 7afadfdc says were folded in by akpm (along with a page->index one): - Don't look up more pages than we're going to use: seems a good thing for me to fold into truncate_inode_pages_range() and invalidate_mapping_pages() too. - Check for the cursor wrapping at the end of the mapping: but with #if BITS_PER_LONG==32 #define MAX_LFS_FILESIZE (((u64)PAGE_CACHE_SIZE << (BITS_PER_LONG-1))-1) #elif BITS_PER_LONG==64 #define MAX_LFS_FILESIZE 0x7fffffffffffffffUL #endif I don't see how page->index + 1 would ever be 0, even if one or other of those "-1"s went away; so may I delete the "wrapped" case? Thanks, Hugh -- 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 internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>