From: Paul Jackson Date: Thu, 25 Aug 2005 19:47:56 +0000 (-0700) Subject: [PATCH] completely disable cpu_exclusive sched domain X-Git-Tag: v2.6.13~19 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=212d6d2237f60bc28c1518f8abf9d3ed6c17574a;p=linux-2.6 [PATCH] completely disable cpu_exclusive sched domain At the suggestion of Nick Piggin and Dinakar, totally disable the facility to allow cpu_exclusive cpusets to define dynamic sched domains in Linux 2.6.13, in order to avoid problems first reported by John Hawkes (corrupt sched data structures and kernel oops). This has been built for ppc64, i386, ia64, x86_64, sparc, alpha. It has been built, booted and tested for cpuset functionality on an SN2 (ia64). Dinakar or Nick - could you verify that it for sure does avoid the problems Hawkes reported. Hawkes is out of town, and I don't have the recipe to reproduce what he found. Signed-off-by: Paul Jackson Acked-by: Nick Piggin Signed-off-by: Linus Torvalds --- diff --git a/kernel/cpuset.c b/kernel/cpuset.c index 21a4e3b2cb..8ab1b4e518 100644 --- a/kernel/cpuset.c +++ b/kernel/cpuset.c @@ -627,6 +627,14 @@ static int validate_change(const struct cpuset *cur, const struct cpuset *trial) * Call with cpuset_sem held. May nest a call to the * lock_cpu_hotplug()/unlock_cpu_hotplug() pair. */ + +/* + * Hack to avoid 2.6.13 partial node dynamic sched domain bug. + * Disable letting 'cpu_exclusive' cpusets define dynamic sched + * domains, until the sched domain can handle partial nodes. + * Remove this #if hackery when sched domains fixed. + */ +#if 0 static void update_cpu_domains(struct cpuset *cur) { struct cpuset *c, *par = cur->parent; @@ -667,6 +675,11 @@ static void update_cpu_domains(struct cpuset *cur) partition_sched_domains(&pspan, &cspan); unlock_cpu_hotplug(); } +#else +static void update_cpu_domains(struct cpuset *cur) +{ +} +#endif static int update_cpumask(struct cpuset *cs, char *buf) {