The patch titled Subject: mm: do not call frontswap_init() during swapoff has been added to the -mm tree. Its filename is mm-do-not-call-frontswap_init-during-swapoff.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/SubmitChecklist when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Cesar Eduardo Barros <cesarb@xxxxxxxxxx> Subject: mm: do not call frontswap_init() during swapoff The call to frontswap_init() was added within enable_swap_info(), which was called not only during sys_swapon, but also to reinsert the swap_info into the swap_list in case of failure of try_to_unuse() within sys_swapoff. This means that frontswap_init() might be called more than once for the same swap area. While as far as I could see no frontswap implementation has any problem with it (and in fact, all the ones I found ignore the parameter passed to frontswap_init), this could change in the future. To prevent future problems, move the call to frontswap_init() to outside the code shared between sys_swapon and sys_swapoff. Signed-off-by: Cesar Eduardo Barros <cesarb@xxxxxxxxxx> Cc: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx> Cc: Dan Magenheimer <dan.magenheimer@xxxxxxxxxx> Cc: Mel Gorman <mgorman@xxxxxxx> Cc: Rik van Riel <riel@xxxxxxxxxx> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx> Cc: Johannes Weiner <hannes@xxxxxxxxxxx> Cc: Hugh Dickins <hughd@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/swapfile.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff -puN mm/swapfile.c~mm-do-not-call-frontswap_init-during-swapoff mm/swapfile.c --- a/mm/swapfile.c~mm-do-not-call-frontswap_init-during-swapoff +++ a/mm/swapfile.c @@ -1471,7 +1471,6 @@ static void _enable_swap_info(struct swa swap_list.head = swap_list.next = p->type; else swap_info[prev]->next = p->type; - frontswap_init(p->type); } static void enable_swap_info(struct swap_info_struct *p, int prio, @@ -1480,6 +1479,7 @@ static void enable_swap_info(struct swap { spin_lock(&swap_lock); _enable_swap_info(p, prio, swap_map, frontswap_map); + frontswap_init(p->type); spin_unlock(&swap_lock); } _ Patches currently in -mm which might be from cesarb@xxxxxxxxxx are linux-next.patch mm-refactor-reinsert-of-swap_info-in-sys_swapoff.patch mm-do-not-call-frontswap_init-during-swapoff.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html