Commit-ID: 00b30cf04a775b5292ab704f782394e36e25617d Gitweb: http://git.kernel.org/tip/00b30cf04a775b5292ab704f782394e36e25617d Author: cpw@xxxxxxx <cpw@xxxxxxx> AuthorDate: Tue, 21 Jun 2011 07:21:26 -0500 Committer: Ingo Molnar <mingo@xxxxxxx> CommitDate: Tue, 21 Jun 2011 14:50:31 +0200 x86, UV: Fix smp_processor_id() use in a preemptable region Fix a call by tunables_write() to smp_processor_id() within a preemptable region. Call get_cpu()/put_cpu() around the region where the returned cpu number is actually used, which makes it non-preemptable. A DEBUG_PREEMPT warning is prevented. UV does not support cpu hotplug yet, but this is a step toward that ability as well. Signed-off-by: Cliff Wickman <cpw@xxxxxxx> Link: http://lkml.kernel.org/r/20110621122242.086384966@xxxxxxx Signed-off-by: Ingo Molnar <mingo@xxxxxxx> --- arch/x86/platform/uv/tlb_uv.c | 5 +++-- 1 files changed, 3 insertions(+), 2 deletions(-) diff --git a/arch/x86/platform/uv/tlb_uv.c b/arch/x86/platform/uv/tlb_uv.c index 68e467f..34be650 100644 --- a/arch/x86/platform/uv/tlb_uv.c +++ b/arch/x86/platform/uv/tlb_uv.c @@ -1334,9 +1334,10 @@ static ssize_t tunables_write(struct file *file, const char __user *user, instr[count] = '\0'; - bcp = &per_cpu(bau_control, smp_processor_id()); - + cpu = get_cpu(); + bcp = &per_cpu(bau_control, cpu); ret = parse_tunables_write(bcp, instr, count); + put_cpu(); if (ret) return ret; -- To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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