From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Mon, 18 Mar 2002 19:25:19 -0300 (BRT) From: Rik van Riel Subject: [RFT][PATCH] oom killer fix ??? Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org Return-Path: To: linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org List-ID: Hi, The -rmap VM has had some problems with the OOM killer triggering before the machine actually ran out of freeable memory. The patch below is an attempt at fixing the OOM killer, it works by: 1) making sure userland allocations can always allocate right down to zone->pages_min, albeit slowly 2) not OOM killing if any zone has more than zone->pages_min in freeable pages I'd appreciate it if the CONFIG_DISCONTIGMEM people could give this patch a try. thank you, Rik -- http://www.surriel.com/ http://distro.conectiva.com/ ===== mm/vmscan.c 1.97 vs edited ===== --- 1.97/mm/vmscan.c Thu Feb 28 20:38:19 2002 +++ edited/mm/vmscan.c Mon Mar 18 16:57:41 2002 @@ -605,7 +605,7 @@ * Hmm.. Cache shrink failed - time to kill something? * Mhwahahhaha! This is the part I really like. Giggle. */ - if (!ret && free_low(ANY_ZONE) > 0) + if (!ret && free_min(ANY_ZONE) > 0) out_of_memory(); return ret; @@ -703,9 +703,11 @@ } } +static int kswapd_overloaded; DECLARE_WAIT_QUEUE_HEAD(kswapd_wait); DECLARE_WAIT_QUEUE_HEAD(kswapd_done); -#define VM_SHOULD_SLEEP (free_low(ALL_ZONES) > (freepages.min / 2)) +#define VM_SHOULD_SLEEP ((free_low(ALL_ZONES) > (freepages.min / 2)) && \ + !kswapd_overloaded) /** * wakeup_kswapd - wake up the pageout daemon @@ -751,27 +753,25 @@ { DECLARE_WAITQUEUE(wait, current); - /* Enough free RAM, we can easily keep up with memory demand. */ add_wait_queue(&kswapd_wait, &wait); set_current_state(TASK_INTERRUPTIBLE); + /* Don't let the processes waiting on memory get stuck, ever. */ + wake_up(&kswapd_done); + + /* Enough free RAM, we can easily keep up with memory demand. */ if (free_high(ALL_ZONES) <= 0) { - wake_up(&kswapd_done); schedule_timeout(HZ); remove_wait_queue(&kswapd_wait, &wait); return; } remove_wait_queue(&kswapd_wait, &wait); - /* - * kswapd is going to sleep for a long time. Wake up the waiters to - * prevent them to get stuck while waiting for us. - */ - wake_up(&kswapd_done); - /* OK, the VM is very loaded. Sleep instead of using all CPU. */ + kswapd_overloaded = 1; set_current_state(TASK_UNINTERRUPTIBLE); schedule_timeout(HZ / 4); + kswapd_overloaded = 0; return; } -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/