From: Paolo 'Blaisorblade' Giarrusso <[EMAIL PROTECTED]> Seems like on 2.4.9.4 this comment got out of sync ;-)
I'm not completely sure on which basis we don't need any more to do as the comment suggests, but it seems that when faulting in a second time the same swap page, can_share_swap_page() returns false, and we do an early COW break, so there's no need to write-protect the page. No idea why we don't defer the COW break. Reference commit from GIT version of BKCVS history: 5ee46c7964de4b1969fc5be036167eb2da0de4e2, BKRev 3c603c81PtWl2I1NnVuphvsItrD1hg (v2.4.9.3 -> v2.4.9.4). Signed-off-by: Paolo 'Blaisorblade' Giarrusso <[EMAIL PROTECTED]> --- linux-2.6.git-paolo/mm/swapfile.c | 5 +---- 1 files changed, 1 insertion(+), 4 deletions(-) diff -puN mm/swapfile.c~remove-stale-comment-swap-file mm/swapfile.c --- linux-2.6.git/mm/swapfile.c~remove-stale-comment-swap-file 2005-08-11 11:13:18.000000000 +0200 +++ linux-2.6.git-paolo/mm/swapfile.c 2005-08-11 11:13:18.000000000 +0200 @@ -388,10 +388,7 @@ void free_swap_and_cache(swp_entry_t ent } /* - * Always set the resulting pte to be nowrite (the same as COW pages - * after one process has exited). We don't know just how many PTEs will - * share this swap entry, so be cautious and let do_wp_page work out - * what to do if a write is requested later. + * Since we're swapping it in, we mark it as old. * * vma->vm_mm->page_table_lock is held. */ _ - 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/
