From: Andrew Morton Date: Sun, 25 Jun 2006 12:47:46 +0000 (-0700) Subject: [PATCH] pdflush: handle resume wakeups X-Git-Tag: v2.6.18-rc1~993 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=d616e09ab33aa4d013a93c9b393efd5cebf78521;p=linux-2.6 [PATCH] pdflush: handle resume wakeups pdflush is carefully designed to ensure that all wakeups have some corresponding work to do - if a woken-up pdflush thread discovers that it hasn't been given any work to do then this is considered an error. That all broke when swsusp came along - because a timer-delivered wakeup to a frozen pdflush thread will just get lost. This causes the pdflush thread to get lost as well: the writeback timer is supposed to be re-armed by pdflush in process context, but pdflush doesn't execute the callout which does this. Fix that up by ignoring the return value from try_to_freeze(): jsut proceed, see if we have any work pending and only go back to sleep if that is not the case. Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/mm/pdflush.c b/mm/pdflush.c index df7e50b8f7..b02102feeb 100644 --- a/mm/pdflush.c +++ b/mm/pdflush.c @@ -104,21 +104,20 @@ static int __pdflush(struct pdflush_work *my_work) list_move(&my_work->list, &pdflush_list); my_work->when_i_went_to_sleep = jiffies; spin_unlock_irq(&pdflush_lock); - schedule(); - if (try_to_freeze()) { - spin_lock_irq(&pdflush_lock); - continue; - } - + try_to_freeze(); spin_lock_irq(&pdflush_lock); if (!list_empty(&my_work->list)) { - printk("pdflush: bogus wakeup!\n"); + /* + * Someone woke us up, but without removing our control + * structure from the global list. swsusp will do this + * in try_to_freeze()->refrigerator(). Handle it. + */ my_work->fn = NULL; continue; } if (my_work->fn == NULL) { - printk("pdflush: NULL work function\n"); + printk("pdflush: bogus wakeup\n"); continue; } spin_unlock_irq(&pdflush_lock);