From 2b744c01a54fe0c9974ff1b29522f25f07084053 Mon Sep 17 00:00:00 2001 From: Yasunori Goto Date: Sun, 6 May 2007 14:49:59 -0700 Subject: [PATCH] mm: fix handling of panic_on_oom when cpusets are in use The current panic_on_oom may not work if there is a process using cpusets/mempolicy, because other nodes' memory may remain. But some people want failover by panic ASAP even if they are used. This patch makes new setting for its request. This is tested on my ia64 box which has 3 nodes. Signed-off-by: Yasunori Goto Signed-off-by: Benjamin LaHaise Cc: Christoph Lameter Cc: Paul Jackson Cc: Ethan Solomita Cc: David Rientjes Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Documentation/sysctl/vm.txt | 23 +++++++++++++++++------ mm/oom_kill.c | 3 +++ 2 files changed, 20 insertions(+), 6 deletions(-) diff --git a/Documentation/sysctl/vm.txt b/Documentation/sysctl/vm.txt index e96a341eb7e..1d192565e18 100644 --- a/Documentation/sysctl/vm.txt +++ b/Documentation/sysctl/vm.txt @@ -197,11 +197,22 @@ and may not be fast. panic_on_oom -This enables or disables panic on out-of-memory feature. If this is set to 1, -the kernel panics when out-of-memory happens. If this is set to 0, the kernel -will kill some rogue process, called oom_killer. Usually, oom_killer can kill -rogue processes and system will survive. If you want to panic the system -rather than killing rogue processes, set this to 1. +This enables or disables panic on out-of-memory feature. -The default value is 0. +If this is set to 0, the kernel will kill some rogue process, +called oom_killer. Usually, oom_killer can kill rogue processes and +system will survive. + +If this is set to 1, the kernel panics when out-of-memory happens. +However, if a process limits using nodes by mempolicy/cpusets, +and those nodes become memory exhaustion status, one process +may be killed by oom-killer. No panic occurs in this case. +Because other nodes' memory may be free. This means system total status +may be not fatal yet. +If this is set to 2, the kernel panics compulsorily even on the +above-mentioned. + +The default value is 0. +1 and 2 are for failover of clustering. Please select either +according to your policy of failover. diff --git a/mm/oom_kill.c b/mm/oom_kill.c index a35e7a8ebd7..038d2234f13 100644 --- a/mm/oom_kill.c +++ b/mm/oom_kill.c @@ -413,6 +413,9 @@ void out_of_memory(struct zonelist *zonelist, gfp_t gfp_mask, int order) show_mem(); } + if (sysctl_panic_on_oom == 2) + panic("out of memory. Compulsory panic_on_oom is selected.\n"); + cpuset_lock(); read_lock(&tasklist_lock); -- 2.39.5