From a6e4491c682a7b28574a62e6f311a0acec50b318 Mon Sep 17 00:00:00 2001 From: Prarit Bhargava Date: Thu, 4 Feb 2016 09:38:00 -0500 Subject: [PATCH] sched/isolcpus: Output warning when the 'isolcpus=' kernel parameter is invalid The isolcpus= kernel boot parameter restricts userspace from scheduling on the specified CPUs. If a CPU is specified that is outside the range of 0 to nr_cpu_ids, cpulist_parse() will return -ERANGE, return an empty cpulist, and fail silently. This patch adds an error message to isolated_cpu_setup() to indicate to the user that something has gone awry, and returns 0 on error. Signed-off-by: Prarit Bhargava Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/1454596680-10367-1-git-send-email-prarit@redhat.com [ Twiddled some details. ] Signed-off-by: Ingo Molnar --- kernel/sched/core.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 9503d590e5ef..24fcdbf28b18 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -6173,11 +6173,16 @@ cpu_attach_domain(struct sched_domain *sd, struct root_domain *rd, int cpu) /* Setup the mask of cpus configured for isolated domains */ static int __init isolated_cpu_setup(char *str) { + int ret; + alloc_bootmem_cpumask_var(&cpu_isolated_map); - cpulist_parse(str, cpu_isolated_map); + ret = cpulist_parse(str, cpu_isolated_map); + if (ret) { + pr_err("sched: Error, all isolcpus= values must be between 0 and %d\n", nr_cpu_ids); + return 0; + } return 1; } - __setup("isolcpus=", isolated_cpu_setup); struct s_data { -- 2.20.1